diff --git a/README.md b/README.md
index 941148d..4cacb04 100644
--- a/README.md
+++ b/README.md
@@ -87,7 +87,7 @@ Show doc comment at the Project view Tree, line End, json etc.
 <li>1.5   Add line-end-comment  find next loop when none
 <li>1.4   Add line-end-comment  find element right to left
 <li>1.3   ★   project-view-tree file and member comment
-<li>1.2   Add line-end-comment  settings fro class prefix filter
+<li>1.2   Add line-end-comment  settings for class prefix filter
 <li>1.1   Add line-end-comment  settings for text color
 </ul>
 
diff --git a/build.gradle b/build.gradle
index 56b1128..73cb8be 100644
--- a/build.gradle
+++ b/build.gradle
@@ -110,7 +110,7 @@ patchPluginXml {
 <li>1.5   Add line-end-comment  find next loop when none
 <li>1.4   Add line-end-comment  find element right to left
 <li>1.3   ★   project-view-tree file and member comment
-<li>1.2   Add line-end-comment  settings fro class prefix filter
+<li>1.2   Add line-end-comment  settings for class prefix filter
 <li>1.1   Add line-end-comment  settings for text color
 </ul>
 
diff --git a/src/main/idea/io/github/linwancen/plugin/show/java/JavaLangDoc.java b/src/main/idea/io/github/linwancen/plugin/show/java/JavaLangDoc.java
index c871213..717a310 100644
--- a/src/main/idea/io/github/linwancen/plugin/show/java/JavaLangDoc.java
+++ b/src/main/idea/io/github/linwancen/plugin/show/java/JavaLangDoc.java
@@ -34,27 +34,28 @@ public class JavaLangDoc extends BaseTagLangDoc<PsiDocComment> {
     }
 
     @Override
-    public @Nullable <T extends SettingsInfo> String treeDoc(T settingsInfo, ProjectViewNode<?> node, Project project) {
+    public @Nullable <T extends SettingsInfo> String treeDoc(@NotNull T settingsInfo, ProjectViewNode<?> node,
+                                                             @NotNull Project project) {
         return JavaTree.treeDoc(settingsInfo, node, project);
     }
 
     @Override
     protected @Nullable <T extends SettingsInfo> String refDoc(@NotNull T lineInfo, @NotNull PsiElement ref) {
         if ("Override".equals(ref.getText())) {
-            PsiMethod psiMethod = PsiTreeUtil.getParentOfType(ref, PsiMethod.class);
+            @Nullable PsiMethod psiMethod = PsiTreeUtil.getParentOfType(ref, PsiMethod.class);
             if (psiMethod == null) {
                 return null;
             }
             // must supper
-            PsiDocComment psiDocComment = OwnerToPsiDocUtils.supperMethodDoc(psiMethod);
+            @Nullable PsiDocComment psiDocComment = OwnerToPsiDocUtils.supperMethodDoc(psiMethod);
             return docElementToStr(lineInfo, psiDocComment);
         }
         if (lineInfo.appSettings.fromNew) {
             PsiElement parent = ref.getParent();
             if (parent instanceof PsiNewExpression) {
-                PsiNewExpression psiNewExpression = (PsiNewExpression) parent;
+                @NotNull PsiNewExpression psiNewExpression = (PsiNewExpression) parent;
                 try {
-                    PsiMethod resolve = psiNewExpression.resolveMethod();
+                    @Nullable PsiMethod resolve = psiNewExpression.resolveMethod();
                     if (resolve != null) {
                         return resolveDocPrint(lineInfo, resolve);
                     }
@@ -68,7 +69,7 @@ public class JavaLangDoc extends BaseTagLangDoc<PsiDocComment> {
 
     @Override
     public @Nullable <T extends SettingsInfo> String resolveDocPrint(@NotNull T lineInfo, @NotNull PsiElement resolve) {
-        String resolveDocPrint = super.resolveDocPrint(lineInfo, resolve);
+        @Nullable String resolveDocPrint = super.resolveDocPrint(lineInfo, resolve);
         if (resolveDocPrint != null) {
             return resolveDocPrint;
         }
@@ -80,20 +81,20 @@ public class JavaLangDoc extends BaseTagLangDoc<PsiDocComment> {
 
     @Nullable
     private String paramDoc(@NotNull PsiParameter psiParameter) {
-        PsiMethod method = PsiTreeUtil.getParentOfType(psiParameter, PsiMethod.class);
+        @Nullable PsiMethod method = PsiTreeUtil.getParentOfType(psiParameter, PsiMethod.class);
         if (method == null) {
             return null;
         }
-        PsiDocComment psiDocComment = OwnerToPsiDocUtils.methodDoc(method);
+        @Nullable PsiDocComment psiDocComment = OwnerToPsiDocUtils.methodDoc(method);
         if (psiDocComment == null) {
             return null;
         }
-        String name = psiParameter.getName();
-        PsiDocTag[] params = psiDocComment.findTagsByName("param");
-        for (PsiDocTag param : params) {
-            PsiDocTagValue value = param.getValueElement();
+        @NotNull String name = psiParameter.getName();
+        @NotNull PsiDocTag[] params = psiDocComment.findTagsByName("param");
+        for (@NotNull PsiDocTag param : params) {
+            @Nullable PsiDocTagValue value = param.getValueElement();
             if (value != null && name.equals(value.getText())) {
-                PsiElement[] dataElements = param.getDataElements();
+                @NotNull PsiElement[] dataElements = param.getDataElements();
                 if (dataElements.length > 1) {
                     return dataElements[1].getText();
                 }
@@ -106,7 +107,7 @@ public class JavaLangDoc extends BaseTagLangDoc<PsiDocComment> {
     @Override
     protected PsiDocComment toDocElement(@NotNull PsiElement resolve) {
         if (resolve instanceof PsiDocCommentOwner) {
-            PsiDocCommentOwner psiDocCommentOwner = (PsiDocCommentOwner) resolve;
+            @NotNull PsiDocCommentOwner psiDocCommentOwner = (PsiDocCommentOwner) resolve;
             return OwnerToPsiDocSkip.refDoc(psiDocCommentOwner);
         }
         return null;
@@ -115,9 +116,9 @@ public class JavaLangDoc extends BaseTagLangDoc<PsiDocComment> {
     @NotNull
     @Override
     protected <T extends SettingsInfo> String descDoc(@NotNull T lineInfo, @NotNull PsiDocComment psiDocComment) {
-        StringBuilder sb = new StringBuilder();
+        @NotNull StringBuilder sb = new StringBuilder();
         int lineCount = 0;
-        PsiElement[] elements = psiDocComment.getDescriptionElements();
+        @NotNull PsiElement[] elements = psiDocComment.getDescriptionElements();
         for (PsiElement element : elements) {
             if (appendElementText(sb, element)) {
                 lineCount++;
@@ -132,14 +133,14 @@ public class JavaLangDoc extends BaseTagLangDoc<PsiDocComment> {
     /**
      * @return is new line
      */
-    private static boolean appendElementText(StringBuilder sb, PsiElement element) {
+    private static boolean appendElementText(@NotNull StringBuilder sb, PsiElement element) {
         if (element instanceof PsiDocToken) {
-            PsiDocToken psiDocToken = (PsiDocToken) element;
+            @NotNull PsiDocToken psiDocToken = (PsiDocToken) element;
             DocFilter.addHtml(sb, psiDocToken.getText());
         }
         if (element instanceof PsiInlineDocTag) {
-            PsiInlineDocTag psiInlineDocTag = (PsiInlineDocTag) element;
-            PsiElement[] children = psiInlineDocTag.getChildren();
+            @NotNull PsiInlineDocTag psiInlineDocTag = (PsiInlineDocTag) element;
+            @NotNull PsiElement[] children = psiInlineDocTag.getChildren();
             if (children.length > 3) {
                 DocFilter.addHtml(sb, children[3].getText());
             }
@@ -150,10 +151,10 @@ public class JavaLangDoc extends BaseTagLangDoc<PsiDocComment> {
     @Override
     protected <T extends SettingsInfo> void appendTag(@NotNull T lineInfo, @NotNull StringBuilder tagStrBuilder,
                                                       @NotNull PsiDocComment psiDocComment, @NotNull String name) {
-        PsiDocTag[] tags = psiDocComment.findTagsByName(name);
-        for (PsiDocTag tag : tags) {
+        @NotNull PsiDocTag[] tags = psiDocComment.findTagsByName(name);
+        for (@NotNull PsiDocTag tag : tags) {
             // @see @param should use getDataElements()
-            PsiDocTagValue value = tag.getValueElement();
+            @Nullable PsiDocTagValue value = tag.getValueElement();
             if (value != null) {
                 DocFilter.addHtml(tagStrBuilder, value.getText());
             }
diff --git a/src/main/idea/io/github/linwancen/plugin/show/java/JavaTree.java b/src/main/idea/io/github/linwancen/plugin/show/java/JavaTree.java
index 07fbf46..8713e9d 100644
--- a/src/main/idea/io/github/linwancen/plugin/show/java/JavaTree.java
+++ b/src/main/idea/io/github/linwancen/plugin/show/java/JavaTree.java
@@ -14,6 +14,7 @@ import io.github.linwancen.plugin.show.bean.SettingsInfo;
 import io.github.linwancen.plugin.show.java.doc.OwnerToPsiDocUtils;
 import io.github.linwancen.plugin.show.java.line.NewCallRefToPsiDoc;
 import io.github.linwancen.plugin.show.settings.AppSettingsState;
+import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
 public class JavaTree {
@@ -21,8 +22,9 @@ public class JavaTree {
     private JavaTree() {}
 
     @Nullable
-    public static <T extends SettingsInfo> String treeDoc(T settingsInfo, ProjectViewNode<?> node, Project project) {
-        PsiDocComment docComment = nodeDoc(node, project);
+    public static <T extends SettingsInfo> String treeDoc(@NotNull T settingsInfo, ProjectViewNode<?> node,
+                                                          @NotNull Project project) {
+        @Nullable PsiDocComment docComment = nodeDoc(node, project);
         if (docComment == null) {
             return null;
         }
@@ -30,7 +32,7 @@ public class JavaTree {
     }
 
     @Nullable
-    static PsiDocComment nodeDoc(ProjectViewNode<?> node, Project project) {
+    static PsiDocComment nodeDoc(ProjectViewNode<?> node, @NotNull Project project) {
         if (node instanceof PsiFileNode) {
             PsiFile psiFile = ((PsiFileNode) node).getValue();
             return OwnerToPsiDocUtils.fileDoc(psiFile);
@@ -44,26 +46,26 @@ public class JavaTree {
             // On Show Members
             PsiField psiField = ((PsiFieldNode) node).getValue();
             // for @Autowire Bean
-            PsiType type = psiField.getType();
+            @NotNull PsiType type = psiField.getType();
             if (type instanceof PsiClassReferenceType) {
-                PsiClassReferenceType psiClassReferenceType = (PsiClassReferenceType) type;
-                PsiJavaCodeReferenceElement reference = psiClassReferenceType.getReference();
+                @NotNull PsiClassReferenceType psiClassReferenceType = (PsiClassReferenceType) type;
+                @NotNull PsiJavaCodeReferenceElement reference = psiClassReferenceType.getReference();
                 return NewCallRefToPsiDoc.javaCodeDoc(reference);
             }
         }
 
         if (node instanceof PackageElementNode) {
             // On Packages View
-            PsiPackage psiPackage = ((PackageElementNode) node).getValue().getPackage();
+            @NotNull PsiPackage psiPackage = ((PackageElementNode) node).getValue().getPackage();
             return packageDoc(psiPackage);
         }
 
         // On Packages View, Project Files View
-        VirtualFile virtualFile = node.getVirtualFile();
+        @Nullable VirtualFile virtualFile = node.getVirtualFile();
         if (virtualFile == null || !virtualFile.isDirectory()) {
             return null;
         }
-        PsiDirectory psiDirectory = PsiManager.getInstance(project).findDirectory(virtualFile);
+        @Nullable PsiDirectory psiDirectory = PsiManager.getInstance(project).findDirectory(virtualFile);
         if (psiDirectory == null) {
             return null;
         }
@@ -71,17 +73,17 @@ public class JavaTree {
     }
 
     @Nullable
-    static PsiDocComment dirDoc(PsiDirectory child) {
+    static PsiDocComment dirDoc(@NotNull PsiDirectory child) {
         while (true) {
-            PsiDocComment docComment = OwnerToPsiDocUtils.dirDoc(child);
+            @Nullable PsiDocComment docComment = OwnerToPsiDocUtils.dirDoc(child);
             if (docComment != null) {
                 return docComment;
             }
-            AppSettingsState instance = AppSettingsState.getInstance();
+            @NotNull AppSettingsState instance = AppSettingsState.getInstance();
             if (!instance.compact) {
                 return null;
             }
-            PsiDirectory parent = child.getParent();
+            @Nullable PsiDirectory parent = child.getParent();
             if (parent == null) {
                 return null;
             }
@@ -93,13 +95,13 @@ public class JavaTree {
     }
 
     @Nullable
-    static PsiDocComment packageDoc(PsiPackage child) {
+    static PsiDocComment packageDoc(@NotNull PsiPackage child) {
         while (true) {
-            PsiDocComment docComment = OwnerToPsiDocUtils.packageDoc(child);
+            @Nullable PsiDocComment docComment = OwnerToPsiDocUtils.packageDoc(child);
             if (docComment != null) {
                 return docComment;
             }
-            PsiPackage parent = child.getParentPackage();
+            @Nullable PsiPackage parent = child.getParentPackage();
             if (parent == null) {
                 return null;
             }
diff --git a/src/main/idea/io/github/linwancen/plugin/show/java/JsonJumpJava.java b/src/main/idea/io/github/linwancen/plugin/show/java/JsonJumpJava.java
index 9f4af59..0913ff5 100644
--- a/src/main/idea/io/github/linwancen/plugin/show/java/JsonJumpJava.java
+++ b/src/main/idea/io/github/linwancen/plugin/show/java/JsonJumpJava.java
@@ -11,6 +11,7 @@ import com.intellij.util.ProcessingContext;
 import io.github.linwancen.plugin.show.java.doc.PsiClassUtils;
 import io.github.linwancen.plugin.show.jump.JsonRef;
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 
 import java.util.ArrayList;
 import java.util.Arrays;
@@ -25,7 +26,8 @@ public class JsonJumpJava extends PsiReferenceContributor {
                     @Override
                     public @NotNull PsiReference[] getReferencesByElement(@NotNull PsiElement element,
                                                                           @NotNull ProcessingContext context) {
-                        JsonProperty jsonProp = PsiTreeUtil.getParentOfType(element, JsonProperty.class, true);
+                        @Nullable JsonProperty jsonProp = PsiTreeUtil.getParentOfType(
+                                element, JsonProperty.class, true);
                         if (jsonProp == null) {
                             return PsiReference.EMPTY_ARRAY;
                         }
@@ -34,15 +36,15 @@ public class JsonJumpJava extends PsiReferenceContributor {
                             return PsiReference.EMPTY_ARRAY;
                         }
 
-                        Project project = element.getProject();
-                        List<PsiField> psiFields = new ArrayList<>();
-                        List<PsiField> tips = new ArrayList<>();
-                        PsiClass[] psiClasses = PsiClassUtils.encClass(virtualFile, project);
-                        List<String> jsonPath = jsonPath(jsonProp);
+                        @NotNull Project project = element.getProject();
+                        @NotNull List<PsiField> psiFields = new ArrayList<>();
+                        @NotNull List<PsiField> tips = new ArrayList<>();
+                        @NotNull PsiClass[] psiClasses = PsiClassUtils.encClass(virtualFile, project);
+                        @NotNull List<String> jsonPath = jsonPath(jsonProp);
                         put(project, psiFields, tips, psiClasses, jsonPath, jsonPath.size() - 1);
 
-                        List<PsiReference> list = new ArrayList<>();
-                        for (PsiField psiField : psiFields) {
+                        @NotNull List<PsiReference> list = new ArrayList<>();
+                        for (@NotNull PsiField psiField : psiFields) {
                             list.add(new JsonRef<>(element, psiField, tips));
                         }
                         return list.toArray(new PsiReference[0]);
@@ -51,30 +53,30 @@ public class JsonJumpJava extends PsiReferenceContributor {
     }
 
     @NotNull
-    private static List<String> jsonPath(JsonProperty jsonProp) {
-        ArrayList<String> jsonPath = new ArrayList<>();
+    private static List<String> jsonPath(@NotNull JsonProperty jsonProp) {
+        @NotNull ArrayList<String> jsonPath = new ArrayList<>();
         do {
             jsonPath.add(jsonProp.getName());
         } while ((jsonProp = PsiTreeUtil.getParentOfType(jsonProp, JsonProperty.class)) != null);
         return jsonPath;
     }
 
-    private static void put(Project project, List<PsiField> psiFields, List<PsiField> tips,
-                            PsiClass[] psiClasses, List<String> jsonPath, int level) {
+    private static void put(@NotNull Project project, @NotNull List<PsiField> psiFields, @NotNull List<PsiField> tips,
+                            @NotNull PsiClass[] psiClasses, @NotNull List<String> jsonPath, int level) {
         String name = jsonPath.get(level);
-        for (PsiClass psiClass : psiClasses) {
+        for (@NotNull PsiClass psiClass : psiClasses) {
             if (level == 1) {
                 tips.addAll(Arrays.asList(psiClass.getAllFields()));
             }
-            PsiField psiField = psiClass.findFieldByName(name, true);
+            @Nullable PsiField psiField = psiClass.findFieldByName(name, true);
             if (psiField == null) {
                 continue;
             }
             if (level == 0) {
                 psiFields.add(psiField);
             } else {
-                String classFullName = PsiClassUtils.toClassFullName(psiField);
-                PsiClass[] classes = PsiClassUtils.fullNameToClass(classFullName, project);
+                @NotNull String classFullName = PsiClassUtils.toClassFullName(psiField);
+                @NotNull PsiClass[] classes = PsiClassUtils.fullNameToClass(classFullName, project);
                 put(project, psiFields, tips, classes, jsonPath, level - 1);
             }
         }
diff --git a/src/main/idea/io/github/linwancen/plugin/show/java/KotlinLangDoc.java b/src/main/idea/io/github/linwancen/plugin/show/java/KotlinLangDoc.java
index b1ee817..e01a554 100644
--- a/src/main/idea/io/github/linwancen/plugin/show/java/KotlinLangDoc.java
+++ b/src/main/idea/io/github/linwancen/plugin/show/java/KotlinLangDoc.java
@@ -39,7 +39,7 @@ public class KotlinLangDoc extends BaseTagLangDoc<KDocSection> {
         if (resolve instanceof PsiPackageBase) {
             return null;
         }
-        KDoc kDoc = PsiTreeUtil.getChildOfType(resolve, KDoc.class);
+        @Nullable KDoc kDoc = PsiTreeUtil.getChildOfType(resolve, KDoc.class);
         if (kDoc == null) {
             return null;
         }
@@ -48,18 +48,18 @@ public class KotlinLangDoc extends BaseTagLangDoc<KDocSection> {
 
     @NotNull
     @Override
-    protected  <T extends SettingsInfo> String descDoc(@NotNull T lineInfo, @NotNull KDocSection kDocSection) {
-        String content = kDocSection.getContent();
+    protected <T extends SettingsInfo> String descDoc(@NotNull T lineInfo, @NotNull KDocSection kDocSection) {
+        @NotNull String content = kDocSection.getContent();
         return DocFilter.cutDoc(content, lineInfo.appSettings, false);
     }
 
     @Override
     protected <T extends SettingsInfo> void appendTag(@NotNull T lineInfo, @NotNull StringBuilder tagStrBuilder,
                                                       @NotNull KDocSection kDocSection, @NotNull String name) {
-        List<KDocTag> tags = kDocSection.findTagsByName(name);
-        for (KDocTag tag : tags) {
-            String content = tag.getContent();
-            String cutDoc = DocFilter.cutDoc(content, lineInfo.appSettings, false);
+        @NotNull List<KDocTag> tags = kDocSection.findTagsByName(name);
+        for (@NotNull KDocTag tag : tags) {
+            @NotNull String content = tag.getContent();
+            @NotNull String cutDoc = DocFilter.cutDoc(content, lineInfo.appSettings, false);
             tagStrBuilder.append(cutDoc);
         }
     }
diff --git a/src/main/idea/io/github/linwancen/plugin/show/java/doc/OwnerToPsiDocUtils.java b/src/main/idea/io/github/linwancen/plugin/show/java/doc/OwnerToPsiDocUtils.java
index ff30dec..d078f68 100644
--- a/src/main/idea/io/github/linwancen/plugin/show/java/doc/OwnerToPsiDocUtils.java
+++ b/src/main/idea/io/github/linwancen/plugin/show/java/doc/OwnerToPsiDocUtils.java
@@ -13,7 +13,8 @@ public class OwnerToPsiDocUtils {
 
     private OwnerToPsiDocUtils() {}
 
-    public static PsiDocComment srcOrByteCodeDoc(PsiDocCommentOwner psiDocCommentOwner) {
+    @Nullable
+    public static PsiDocComment srcOrByteCodeDoc(@NotNull PsiDocCommentOwner psiDocCommentOwner) {
         PsiElement navElement = psiDocCommentOwner.getNavigationElement();
         if (navElement instanceof PsiDocCommentOwner) {
             psiDocCommentOwner = (PsiDocCommentOwner) navElement;
@@ -27,7 +28,7 @@ public class OwnerToPsiDocUtils {
     }
 
     @Nullable
-    public static PsiDocComment supperMethodDoc(PsiMethod psiMethod) {
+    public static PsiDocComment supperMethodDoc(@NotNull PsiMethod psiMethod) {
         return PsiMethodToPsiDoc.supperMethodDoc(psiMethod);
     }
 
@@ -36,14 +37,14 @@ public class OwnerToPsiDocUtils {
         if (psiPackage == null) {
             return null;
         }
-        String name = psiPackage.getName();
+        @Nullable String name = psiPackage.getName();
         if (name == null || name.length() == 0) {
             return null;
         }
-        PsiDirectory[] psiDirectories = psiPackage.getDirectories();
-        for (PsiDirectory psiDirectory : psiDirectories) {
-            PsiFile file = psiDirectory.findFile(PsiPackage.PACKAGE_INFO_FILE);
-            PsiDocComment psiDocComment = PackageFileToPsiDoc.fromPackageInfoFile(file);
+        @NotNull PsiDirectory[] psiDirectories = psiPackage.getDirectories();
+        for (@NotNull PsiDirectory psiDirectory : psiDirectories) {
+            @Nullable PsiFile file = psiDirectory.findFile(PsiPackage.PACKAGE_INFO_FILE);
+            @Nullable PsiDocComment psiDocComment = PackageFileToPsiDoc.fromPackageInfoFile(file);
             if (psiDocComment != null) {
                 return psiDocComment;
             }
@@ -55,14 +56,14 @@ public class OwnerToPsiDocUtils {
     public static PsiDocComment fileDoc(PsiFile psiFile) {
         if (!(psiFile instanceof PsiClassOwner)) {
             // for SPI
-            PsiClass[] psiClasses = PsiClassUtils.nameToClass(psiFile.getName(), psiFile.getProject());
+            @NotNull PsiClass[] psiClasses = PsiClassUtils.nameToClass(psiFile.getName(), psiFile.getProject());
             // for "xxx ClassName.xxx"
             if (psiClasses.length == 0) {
                 VirtualFile virtualFile = psiFile.getVirtualFile();
                 psiClasses = PsiClassUtils.encClass(virtualFile, psiFile.getProject());
             }
-            for (PsiClass psiClass : psiClasses) {
-                PsiDocComment docComment = srcOrByteCodeDoc(psiClass);
+            for (@NotNull PsiClass psiClass : psiClasses) {
+                @Nullable PsiDocComment docComment = srcOrByteCodeDoc(psiClass);
                 if (docComment != null) {
                     // Inaccurate when there are classes with the same name
                     return docComment;
@@ -73,8 +74,8 @@ public class OwnerToPsiDocUtils {
         if (PsiPackage.PACKAGE_INFO_FILE.equals(psiFile.getName())) {
             return PackageFileToPsiDoc.fromPackageInfoFile(psiFile);
         }
-        PsiClassOwner psiClassOwner = (PsiClassOwner) psiFile;
-        PsiClass[] classes = psiClassOwner.getClasses();
+        @NotNull PsiClassOwner psiClassOwner = (PsiClassOwner) psiFile;
+        @NotNull PsiClass[] classes = psiClassOwner.getClasses();
         if (classes.length == 0) {
             return null;
         }
@@ -83,8 +84,8 @@ public class OwnerToPsiDocUtils {
     }
 
     @Nullable
-    public static PsiDocComment dirDoc(PsiDirectory psiDirectory) {
-        PsiPackage psiPackage = JavaDirectoryService.getInstance().getPackage(psiDirectory);
+    public static PsiDocComment dirDoc(@NotNull PsiDirectory psiDirectory) {
+        @Nullable PsiPackage psiPackage = JavaDirectoryService.getInstance().getPackage(psiDirectory);
         return packageDoc(psiPackage);
     }
 }
diff --git a/src/main/idea/io/github/linwancen/plugin/show/java/doc/PackageFileToPsiDoc.java b/src/main/idea/io/github/linwancen/plugin/show/java/doc/PackageFileToPsiDoc.java
index 6855283..1bb7a82 100644
--- a/src/main/idea/io/github/linwancen/plugin/show/java/doc/PackageFileToPsiDoc.java
+++ b/src/main/idea/io/github/linwancen/plugin/show/java/doc/PackageFileToPsiDoc.java
@@ -13,7 +13,7 @@ class PackageFileToPsiDoc {
     private PackageFileToPsiDoc() {}
 
     @Nullable
-    static PsiDocComment fromPackageInfoFile(PsiFile packageInfoFile) {
+    static PsiDocComment fromPackageInfoFile(@Nullable PsiFile packageInfoFile) {
         if (packageInfoFile == null) {
             return null;
         }
@@ -21,15 +21,16 @@ class PackageFileToPsiDoc {
         if (astNode == null) {
             return null;
         }
-        ASTNode docCommentNode = findRelevantCommentNode(astNode);
+        @Nullable ASTNode docCommentNode = findRelevantCommentNode(astNode);
         if (docCommentNode == null) {
             return null;
         }
         return (PsiDocComment) docCommentNode;
     }
 
+    @Nullable
     private static ASTNode findRelevantCommentNode(@NotNull ASTNode fileNode) {
-        ASTNode node = fileNode.findChildByType(JavaElementType.PACKAGE_STATEMENT);
+        @Nullable ASTNode node = fileNode.findChildByType(JavaElementType.PACKAGE_STATEMENT);
         if (node == null) node = fileNode.getLastChildNode();
         while (node != null && node.getElementType() != JavaDocElementType.DOC_COMMENT) {
             node = node.getTreePrev();
diff --git a/src/main/idea/io/github/linwancen/plugin/show/java/doc/PsiClassUtils.java b/src/main/idea/io/github/linwancen/plugin/show/java/doc/PsiClassUtils.java
index af34b81..a4aa8d4 100644
--- a/src/main/idea/io/github/linwancen/plugin/show/java/doc/PsiClassUtils.java
+++ b/src/main/idea/io/github/linwancen/plugin/show/java/doc/PsiClassUtils.java
@@ -21,8 +21,8 @@ public class PsiClassUtils {
 
     @NotNull
     public static PsiClass[] encClass(@NotNull VirtualFile virtualFile, @NotNull Project project) {
-        String fileName = virtualFile.getNameWithoutExtension();
-        Matcher matcher = JSON_PATTERN.matcher(fileName);
+        @NotNull String fileName = virtualFile.getNameWithoutExtension();
+        @NotNull Matcher matcher = JSON_PATTERN.matcher(fileName);
         if (!matcher.find()) {
             return new PsiClass[0];
         }
@@ -58,10 +58,10 @@ public class PsiClassUtils {
     }
 
     @NotNull
-    public static String toClassFullName(PsiField psiField) {
+    public static String toClassFullName(@NotNull PsiField psiField) {
         // Array
         // use replace simpler than getDeepComponentType()
-        String typeName = psiField.getType().getCanonicalText().replace("[]", "");
+        @NotNull String typeName = psiField.getType().getCanonicalText().replace("[]", "");
         // List
         // use substring() because clsFieldImpl.getInnermostComponentReferenceElement() == null
         int index = typeName.indexOf("<");
diff --git a/src/main/idea/io/github/linwancen/plugin/show/java/doc/PsiMethodToPsiDoc.java b/src/main/idea/io/github/linwancen/plugin/show/java/doc/PsiMethodToPsiDoc.java
index a9a96ee..02ba2fd 100644
--- a/src/main/idea/io/github/linwancen/plugin/show/java/doc/PsiMethodToPsiDoc.java
+++ b/src/main/idea/io/github/linwancen/plugin/show/java/doc/PsiMethodToPsiDoc.java
@@ -20,19 +20,19 @@ class PsiMethodToPsiDoc {
             psiMethod = (PsiMethod) navElement;
         }
 
-        PsiDocComment docComment = psiMethod.getDocComment();
+        @Nullable PsiDocComment docComment = psiMethod.getDocComment();
         if (docComment != null) {
             return docComment;
         }
 
         // supper
-        PsiDocComment superDoc = supperMethodDoc(psiMethod);
+        @Nullable PsiDocComment superDoc = supperMethodDoc(psiMethod);
         if (superDoc != null) {
             return superDoc;
         }
 
 
-        PsiClass clazz = psiMethod.getContainingClass();
+        @Nullable PsiClass clazz = psiMethod.getContainingClass();
         if (clazz == null) {
             return null;
         }
@@ -47,10 +47,10 @@ class PsiMethodToPsiDoc {
     }
 
     @Nullable
-    static PsiDocComment supperMethodDoc(PsiMethod psiMethod) {
-        PsiMethod[] superMethods = psiMethod.findSuperMethods();
-        for (PsiMethod superMethod : superMethods) {
-            PsiDocComment superDoc = OwnerToPsiDocUtils.methodDoc(superMethod);
+    static PsiDocComment supperMethodDoc(@NotNull PsiMethod psiMethod) {
+        @NotNull PsiMethod[] superMethods = psiMethod.findSuperMethods();
+        for (@NotNull PsiMethod superMethod : superMethods) {
+            @Nullable PsiDocComment superDoc = OwnerToPsiDocUtils.methodDoc(superMethod);
             if (superDoc != null) {
                 return superDoc;
             }
@@ -59,8 +59,8 @@ class PsiMethodToPsiDoc {
     }
 
     @Nullable
-    private static PsiDocComment propMethodDoc(PsiMethod psiMethod, PsiClass psiClass) {
-        String name = psiMethod.getName();
+    private static PsiDocComment propMethodDoc(@NotNull PsiMethod psiMethod, @NotNull PsiClass psiClass) {
+        @NotNull String name = psiMethod.getName();
         if (name.length() > 3 && (name.startsWith("get") || name.startsWith("set"))) {
             name = name.substring(3);
         } else if (name.length() > 2 && name.startsWith("is")) {
@@ -68,10 +68,10 @@ class PsiMethodToPsiDoc {
         } else {
             return null;
         }
-        char[] chars = name.toCharArray();
+        @NotNull char[] chars = name.toCharArray();
         chars[0] += 32;
         name = String.valueOf(chars);
-        PsiField fieldByName = psiClass.findFieldByName(name, false);
+        @Nullable PsiField fieldByName = psiClass.findFieldByName(name, false);
         if (fieldByName == null) {
             return null;
         }
diff --git a/src/main/idea/io/github/linwancen/plugin/show/java/line/NewCallRefToPsiDoc.java b/src/main/idea/io/github/linwancen/plugin/show/java/line/NewCallRefToPsiDoc.java
index 3f4d203..0c0d8de 100644
--- a/src/main/idea/io/github/linwancen/plugin/show/java/line/NewCallRefToPsiDoc.java
+++ b/src/main/idea/io/github/linwancen/plugin/show/java/line/NewCallRefToPsiDoc.java
@@ -14,11 +14,11 @@ public class NewCallRefToPsiDoc {
     private NewCallRefToPsiDoc() {}
 
     @Nullable
-    public static PsiDocComment javaCodeDoc(PsiJavaCodeReferenceElement ref) {
+    public static PsiDocComment javaCodeDoc(@Nullable PsiJavaCodeReferenceElement ref) {
         if (ref == null) {
             return null;
         }
-        PsiElement resolve = null;
+        @Nullable PsiElement resolve = null;
         try {
             resolve = ref.resolve();
         } catch (Throwable ignore) {
diff --git a/src/main/idea/io/github/linwancen/plugin/show/java/line/OwnerToPsiDocSkip.java b/src/main/idea/io/github/linwancen/plugin/show/java/line/OwnerToPsiDocSkip.java
index 7baccce..873c7bb 100644
--- a/src/main/idea/io/github/linwancen/plugin/show/java/line/OwnerToPsiDocSkip.java
+++ b/src/main/idea/io/github/linwancen/plugin/show/java/line/OwnerToPsiDocSkip.java
@@ -6,6 +6,7 @@ import com.intellij.psi.javadoc.PsiDocComment;
 import io.github.linwancen.plugin.show.java.doc.OwnerToPsiDocUtils;
 import io.github.linwancen.plugin.show.settings.AppSettingsState;
 import io.github.linwancen.plugin.show.settings.ProjectSettingsState;
+import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
 /**
@@ -19,12 +20,12 @@ public class OwnerToPsiDocSkip {
         if (docOwner == null) {
             return null;
         }
-        AppSettingsState appSettings = AppSettingsState.getInstance();
-        ProjectSettingsState projectSettings = ProjectSettingsState.getInstance(docOwner.getProject());
+        @NotNull AppSettingsState appSettings = AppSettingsState.getInstance();
+        @NotNull ProjectSettingsState projectSettings = ProjectSettingsState.getInstance(docOwner.getProject());
         if (SkipUtils.skipSign(docOwner, appSettings, projectSettings)) {
             return null;
         }
-        PsiDocComment docComment = docOwner instanceof PsiMethod
+        @Nullable PsiDocComment docComment = docOwner instanceof PsiMethod
                 ? OwnerToPsiDocUtils.methodDoc(((PsiMethod) docOwner))
                 : OwnerToPsiDocUtils.srcOrByteCodeDoc(docOwner);
         return SkipUtils.skipDoc(docComment, appSettings, projectSettings);
diff --git a/src/main/idea/io/github/linwancen/plugin/show/java/line/SkipUtils.java b/src/main/idea/io/github/linwancen/plugin/show/java/line/SkipUtils.java
index 12a3c31..c966765 100644
--- a/src/main/idea/io/github/linwancen/plugin/show/java/line/SkipUtils.java
+++ b/src/main/idea/io/github/linwancen/plugin/show/java/line/SkipUtils.java
@@ -8,39 +8,41 @@ import io.github.linwancen.plugin.show.lang.base.DocSkip;
 import io.github.linwancen.plugin.show.settings.AppSettingsState;
 import io.github.linwancen.plugin.show.settings.ProjectSettingsState;
 import org.apache.commons.lang3.StringUtils;
+import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
 class SkipUtils {
 
     private SkipUtils() {}
 
-    static boolean skipSign(PsiElement psiElement, AppSettingsState appSettings, ProjectSettingsState projectSettings) {
-        String text = psiName(psiElement, appSettings);
+    static boolean skipSign(PsiElement psiElement, @NotNull AppSettingsState appSettings,
+                            @NotNull ProjectSettingsState projectSettings) {
+        @Nullable String text = psiName(psiElement, appSettings);
         if (text == null) {
             return true;
         }
         return DocSkip.skipSign(appSettings, projectSettings, text);
     }
 
-    private static @Nullable String psiName(@Nullable PsiElement psiElement, AppSettingsState appSettings) {
+    private static @Nullable String psiName(@Nullable PsiElement psiElement, @NotNull AppSettingsState appSettings) {
         if (psiElement instanceof PsiClass) {
-            PsiClass psiClass = (PsiClass) psiElement;
+            @NotNull PsiClass psiClass = (PsiClass) psiElement;
             if (appSettings.skipAnnotation && psiClass.isAnnotationType()) {
                 return null;
             }
             return psiClass.getQualifiedName();
         } else if (psiElement instanceof PsiMember) {
-            PsiMember psiMember = (PsiMember) psiElement;
-            StringBuilder sb = new StringBuilder();
-            PsiClass psiClass = psiMember.getContainingClass();
+            @NotNull PsiMember psiMember = (PsiMember) psiElement;
+            @NotNull StringBuilder sb = new StringBuilder();
+            @Nullable PsiClass psiClass = psiMember.getContainingClass();
             if (psiClass != null) {
-                String className = psiClass.getQualifiedName();
+                @Nullable String className = psiClass.getQualifiedName();
                 if (className != null) {
                     sb.append(className);
                 }
             }
             sb.append("#");
-            String name = psiMember.getName();
+            @Nullable String name = psiMember.getName();
             if (name != null) {
                 sb.append(name);
             }
@@ -49,7 +51,8 @@ class SkipUtils {
         return null;
     }
 
-    static PsiDocComment skipDoc(PsiDocComment doc, AppSettingsState appSettings, ProjectSettingsState projectSettings) {
+    static PsiDocComment skipDoc(@Nullable PsiDocComment doc, @NotNull AppSettingsState appSettings,
+                                 @NotNull ProjectSettingsState projectSettings) {
         if (doc == null) {
             return null;
         }
@@ -61,9 +64,9 @@ class SkipUtils {
         return skip ? null : doc;
     }
 
-    private static boolean isBlank(PsiDocComment doc) {
-        PsiElement[] elements = doc.getDescriptionElements();
-        for (PsiElement element : elements) {
+    private static boolean isBlank(@NotNull PsiDocComment doc) {
+        @NotNull PsiElement[] elements = doc.getDescriptionElements();
+        for (@NotNull PsiElement element : elements) {
             String text = element.getText();
             if (StringUtils.isNotBlank(text)) {
                 return false;
diff --git a/src/main/java/io/github/linwancen/plugin/show/CopyReferenceSimple.java b/src/main/java/io/github/linwancen/plugin/show/CopyReferenceSimple.java
index e5a0bfc..0e0b6f2 100644
--- a/src/main/java/io/github/linwancen/plugin/show/CopyReferenceSimple.java
+++ b/src/main/java/io/github/linwancen/plugin/show/CopyReferenceSimple.java
@@ -10,6 +10,7 @@ import com.intellij.psi.PsiDocumentManager;
 import com.intellij.psi.PsiElement;
 import com.intellij.psi.PsiFile;
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 
 import java.util.List;
 import java.util.regex.Pattern;
@@ -27,16 +28,17 @@ public class CopyReferenceSimple extends CopyReferenceAction {
 
     private static final Pattern QUALIFIED_PATTERN = Pattern.compile("[\\w.]+\\.");
 
+    @Nullable
     @Override
-    protected String getQualifiedName(Editor editor, List<PsiElement> elements) {
+    protected String getQualifiedName(@NotNull Editor editor, List<PsiElement> elements) {
         String qualifiedName = super.getQualifiedName(editor, elements);
         if (qualifiedName == null) {
-            Document document = editor.getDocument();
-            Project project = editor.getProject();
+            @NotNull Document document = editor.getDocument();
+            @Nullable Project project = editor.getProject();
             if (project == null) {
                 return null;
             }
-            PsiFile file = PsiDocumentManager.getInstance(project).getCachedPsiFile(document);
+            @Nullable PsiFile file = PsiDocumentManager.getInstance(project).getCachedPsiFile(document);
             if (file != null) {
                 // getFileFqn(file) => file.getName()
                 return file.getName() + ":" + (editor.getCaretModel().getLogicalPosition().line + 1);
diff --git a/src/main/java/io/github/linwancen/plugin/show/LineEnd.java b/src/main/java/io/github/linwancen/plugin/show/LineEnd.java
index f211b39..055dc52 100644
--- a/src/main/java/io/github/linwancen/plugin/show/LineEnd.java
+++ b/src/main/java/io/github/linwancen/plugin/show/LineEnd.java
@@ -24,7 +24,7 @@ public class LineEnd extends EditorLinePainter {
     @Override
     public @Nullable Collection<LineExtensionInfo> getLineExtensions(@NotNull Project project,
                                                                      @NotNull VirtualFile file, int lineNumber) {
-        AppSettingsState settings = AppSettingsState.getInstance();
+        @NotNull AppSettingsState settings = AppSettingsState.getInstance();
         if (!settings.showLineEndComment) {
             return null;
         }
@@ -34,30 +34,30 @@ public class LineEnd extends EditorLinePainter {
         if (!file.exists()) {
             return null;
         }
-        LineInfo lineInfo = LineInfo.of(file, project, lineNumber);
-        String doc = lineDocSkipHave(lineInfo);
+        @Nullable LineInfo lineInfo = LineInfo.of(file, project, lineNumber);
+        @Nullable String doc = lineDocSkipHave(lineInfo);
         if (doc == null) {
             return null;
         }
-        TextAttributes textAttr = file.getFileType().equals(JsonFileType.INSTANCE)
+        @NotNull TextAttributes textAttr = file.getFileType().equals(JsonFileType.INSTANCE)
                 || file.getFileType().equals(Json5FileType.INSTANCE)
                 ? settings.lineEndJsonTextAttr
                 : settings.lineEndTextAttr;
-        LineExtensionInfo info = new LineExtensionInfo(settings.lineEndPrefix + doc, textAttr);
+        @NotNull LineExtensionInfo info = new LineExtensionInfo(settings.lineEndPrefix + doc, textAttr);
         return Collections.singletonList(info);
     }
 
     @NotNull
     public static String textWithDoc(@NotNull FileInfo fileInfo, int startLine, int endLine) {
-        StringBuilder sb = new StringBuilder();
+        @NotNull StringBuilder sb = new StringBuilder();
         for (int i = startLine; i <= endLine; i++) {
-            LineInfo lineInfo = LineInfo.of(fileInfo, i);
+            @Nullable LineInfo lineInfo = LineInfo.of(fileInfo, i);
             if (lineInfo == null) {
                 sb.append("\n");
                 continue;
             }
             sb.append(lineInfo.text);
-            String doc = lineDocSkipHave(lineInfo);
+            @Nullable String doc = lineDocSkipHave(lineInfo);
             if (doc != null) {
                 sb.append(lineInfo.appSettings.lineEndPrefix).append(doc);
             }
@@ -70,11 +70,11 @@ public class LineEnd extends EditorLinePainter {
     }
 
     private static @Nullable String lineDocSkipHave(@Nullable LineInfo lineInfo) {
-        String doc = lineDoc(lineInfo);
+        @Nullable String doc = lineDoc(lineInfo);
         if (doc == null) {
             return null;
         }
-        String trimDoc = doc.trim();
+        @NotNull String trimDoc = doc.trim();
         if (lineInfo.text.trim().endsWith(trimDoc)) {
             return null;
         }
@@ -86,7 +86,7 @@ public class LineEnd extends EditorLinePainter {
             return null;
         }
         // override some text
-        String doc = LineExt.doc(lineInfo);
+        @Nullable String doc = LineExt.doc(lineInfo);
         if (doc != null) {
             return doc;
         }
diff --git a/src/main/java/io/github/linwancen/plugin/show/LineEndAdd.java b/src/main/java/io/github/linwancen/plugin/show/LineEndAdd.java
index 1d53708..f3b057f 100644
--- a/src/main/java/io/github/linwancen/plugin/show/LineEndAdd.java
+++ b/src/main/java/io/github/linwancen/plugin/show/LineEndAdd.java
@@ -13,6 +13,7 @@ import com.intellij.openapi.vfs.VirtualFile;
 import com.intellij.openapi.vfs.VirtualFileVisitor;
 import io.github.linwancen.plugin.show.bean.FileInfo;
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 
 /**
  * on ProjectViewPopupMenu
@@ -21,22 +22,22 @@ public class LineEndAdd extends DumbAwareAction {
 
     @Override
     public void actionPerformed(@NotNull AnActionEvent event) {
-        Project project = event.getProject();
+        @Nullable Project project = event.getProject();
         if (project == null) {
             return;
         }
-        VirtualFile[] files = event.getData(CommonDataKeys.VIRTUAL_FILE_ARRAY);
+        @Nullable VirtualFile[] files = event.getData(CommonDataKeys.VIRTUAL_FILE_ARRAY);
         if (files == null) {
             return;
         }
-        ListPopup confirmation = JBPopupFactory.getInstance().createConfirmation(
+        @NotNull ListPopup confirmation = JBPopupFactory.getInstance().createConfirmation(
                 "Add Line Comment?", "Add and replace files!", "Don't add.",
                 () -> ApplicationManager.getApplication().runReadAction(() -> addDocAll(project, files)), 2);
         confirmation.showInFocusCenter();
     }
 
     private void addDocAll(@NotNull Project project, @NotNull VirtualFile[] files) {
-        for (VirtualFile file : files) {
+        for (@NotNull VirtualFile file : files) {
             VfsUtilCore.visitChildrenRecursively(file, new VirtualFileVisitor<Void>() {
                 @Override
                 public boolean visitFile(@NotNull VirtualFile file) {
@@ -50,13 +51,13 @@ public class LineEndAdd extends DumbAwareAction {
     }
 
     private void addDoc(@NotNull Project project, @NotNull VirtualFile file) {
-        FileInfo fileInfo = FileInfo.of(file, project);
+        @Nullable FileInfo fileInfo = FileInfo.of(file, project);
         if (fileInfo == null) {
             return;
         }
         int startLine = 0;
         int endLine = fileInfo.document.getLineCount() - 1;
-        String textWithDoc = LineEnd.textWithDoc(fileInfo, startLine, endLine);
+        @NotNull String textWithDoc = LineEnd.textWithDoc(fileInfo, startLine, endLine);
         WriteCommandAction.runWriteCommandAction(project, () ->
                 fileInfo.document.replaceString(0, fileInfo.document.getTextLength() - 1, textWithDoc)
         );
diff --git a/src/main/java/io/github/linwancen/plugin/show/LineEndCopy.java b/src/main/java/io/github/linwancen/plugin/show/LineEndCopy.java
index 8f840cd..fc33e65 100644
--- a/src/main/java/io/github/linwancen/plugin/show/LineEndCopy.java
+++ b/src/main/java/io/github/linwancen/plugin/show/LineEndCopy.java
@@ -9,6 +9,7 @@ import com.intellij.openapi.ide.CopyPasteManager;
 import com.intellij.openapi.project.DumbAwareAction;
 import io.github.linwancen.plugin.show.bean.FileInfo;
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 
 import java.awt.datatransfer.StringSelection;
 
@@ -23,16 +24,16 @@ public class LineEndCopy extends DumbAwareAction {
     }
 
     private void copyWithDoc(@NotNull AnActionEvent event) {
-        FileInfo fileInfo = FileInfo.of(event);
+        @Nullable FileInfo fileInfo = FileInfo.of(event);
         if (fileInfo == null) {
             return;
         }
         int startLine = 0;
         int endLine = fileInfo.document.getLineCount() - 1;
         // if select
-        Editor editor = event.getData(CommonDataKeys.EDITOR);
+        @Nullable Editor editor = event.getData(CommonDataKeys.EDITOR);
         if (editor != null) {
-            Caret primaryCaret = editor.getCaretModel().getPrimaryCaret();
+            @NotNull Caret primaryCaret = editor.getCaretModel().getPrimaryCaret();
             int start = primaryCaret.getSelectionStart();
             int end = primaryCaret.getSelectionEnd();
             try {
@@ -42,8 +43,8 @@ public class LineEndCopy extends DumbAwareAction {
                 return;
             }
         }
-        String textWithDoc = LineEnd.textWithDoc(fileInfo, startLine, endLine);
-        StringSelection content = new StringSelection(textWithDoc);
+        @NotNull String textWithDoc = LineEnd.textWithDoc(fileInfo, startLine, endLine);
+        @NotNull StringSelection content = new StringSelection(textWithDoc);
         CopyPasteManager.getInstance().setContents(content);
     }
 }
\ No newline at end of file
diff --git a/src/main/java/io/github/linwancen/plugin/show/Tree.java b/src/main/java/io/github/linwancen/plugin/show/Tree.java
index 3d3e461..09a6789 100644
--- a/src/main/java/io/github/linwancen/plugin/show/Tree.java
+++ b/src/main/java/io/github/linwancen/plugin/show/Tree.java
@@ -25,11 +25,11 @@ import java.util.List;
 public class Tree implements ProjectViewNodeDecorator {
 
     @Override
-    public void decorate(ProjectViewNode node, PresentationData data) {
+    public void decorate(@NotNull ProjectViewNode node, @NotNull PresentationData data) {
         if (!AppSettingsState.getInstance().showTreeComment) {
             return;
         }
-        Project project = node.getProject();
+        @Nullable Project project = node.getProject();
         if (project == null) {
             return;
         }
@@ -37,11 +37,11 @@ public class Tree implements ProjectViewNodeDecorator {
             return;
         }
         ApplicationManager.getApplication().runReadAction(() -> {
-            String doc = treeDoc(node, project);
+            @Nullable String doc = treeDoc(node, project);
             if (doc == null) {
                 return;
             }
-            List<ColoredFragment> coloredText = data.getColoredText();
+            @NotNull List<ColoredFragment> coloredText = data.getColoredText();
             if (coloredText.isEmpty()) {
                 data.addText(data.getPresentableText(), SimpleTextAttributes.REGULAR_ATTRIBUTES);
             }
@@ -50,23 +50,23 @@ public class Tree implements ProjectViewNodeDecorator {
     }
 
     @Nullable
-    private String treeDoc(ProjectViewNode<?> node, @NotNull Project project) {
-        String doc = TreeExt.doc(node);
+    private String treeDoc(@NotNull ProjectViewNode<?> node, @NotNull Project project) {
+        @Nullable String doc = TreeExt.doc(node);
         if (doc != null) {
             return doc;
         }
-        SettingsInfo settingsInfo = SettingsInfo.of(project, FuncEnum.TREE);
+        @NotNull SettingsInfo settingsInfo = SettingsInfo.of(project, FuncEnum.TREE);
         Object value = node.getValue();
         if (value instanceof PsiElement) {
-            PsiElement psiElement = (PsiElement) value;
-            String docPrint = BaseLangDoc.resolveDoc(settingsInfo, psiElement);
+            @NotNull PsiElement psiElement = (PsiElement) value;
+            @Nullable String docPrint = BaseLangDoc.resolveDoc(settingsInfo, psiElement);
             if (docPrint != null) {
                 return docPrint;
             }
         }
-        Collection<BaseLangDoc> langDocs = BaseLangDoc.LANG_DOC_MAP.values();
-        for (BaseLangDoc langDoc : langDocs) {
-            String s = langDoc.treeDoc(settingsInfo, node, project);
+        @NotNull Collection<BaseLangDoc> langDocs = BaseLangDoc.LANG_DOC_MAP.values();
+        for (@NotNull BaseLangDoc langDoc : langDocs) {
+            @Nullable String s = langDoc.treeDoc(settingsInfo, node, project);
             if (s != null) {
                 return s;
             }
diff --git a/src/main/java/io/github/linwancen/plugin/show/bean/FileInfo.java b/src/main/java/io/github/linwancen/plugin/show/bean/FileInfo.java
index 564b50e..48a8662 100644
--- a/src/main/java/io/github/linwancen/plugin/show/bean/FileInfo.java
+++ b/src/main/java/io/github/linwancen/plugin/show/bean/FileInfo.java
@@ -27,30 +27,30 @@ public class FileInfo extends SettingsInfo {
         this.document = document;
     }
 
-    public static @Nullable FileInfo of(@NotNull VirtualFile file, @NotNull Project project){
-        Document document = FileDocumentManager.getInstance().getDocument(file);
+    public static @Nullable FileInfo of(@NotNull VirtualFile file, @NotNull Project project) {
+        @Nullable Document document = FileDocumentManager.getInstance().getDocument(file);
         if (document == null) {
             return null;
         }
-        FileViewProvider viewProvider = PsiManager.getInstance(project).findViewProvider(file);
+        @Nullable FileViewProvider viewProvider = PsiManager.getInstance(project).findViewProvider(file);
         if (viewProvider == null) {
             return null;
         }
         return new FileInfo(file, document, project, viewProvider, FuncEnum.LINE);
     }
 
-    public static @Nullable FileInfo of(@NotNull AnActionEvent event){
-        PsiFile psiFile = event.getData(CommonDataKeys.PSI_FILE);
+    public static @Nullable FileInfo of(@NotNull AnActionEvent event) {
+        @Nullable PsiFile psiFile = event.getData(CommonDataKeys.PSI_FILE);
         if (psiFile == null) {
             return null;
         }
-        FileViewProvider viewProvider = psiFile.getViewProvider();
-        Document document = viewProvider.getDocument();
+        @NotNull FileViewProvider viewProvider = psiFile.getViewProvider();
+        @Nullable Document document = viewProvider.getDocument();
         if (document == null) {
             return null;
         }
-        VirtualFile file = viewProvider.getVirtualFile();
-        Project project = psiFile.getProject();
+        @NotNull VirtualFile file = viewProvider.getVirtualFile();
+        @NotNull Project project = psiFile.getProject();
         return new FileInfo(file, document, project, viewProvider, FuncEnum.LINE);
     }
 }
diff --git a/src/main/java/io/github/linwancen/plugin/show/bean/FuncEnum.java b/src/main/java/io/github/linwancen/plugin/show/bean/FuncEnum.java
index 60d1478..61cde1a 100644
--- a/src/main/java/io/github/linwancen/plugin/show/bean/FuncEnum.java
+++ b/src/main/java/io/github/linwancen/plugin/show/bean/FuncEnum.java
@@ -1,9 +1,11 @@
 package io.github.linwancen.plugin.show.bean;
 
+import org.jetbrains.annotations.NotNull;
+
 import java.util.LinkedHashMap;
 
 public enum FuncEnum {
-    /** tree: project view tree  */
+    /** tree: project view tree */
     TREE("tree", "project view tree"),
     /** line: code line end */
     LINE("line", "code line end"),
@@ -17,16 +19,18 @@ public enum FuncEnum {
         this.desc = desc;
     }
 
+    @NotNull
     @Override
     public String toString() {
         return code + '-' + desc;
     }
 
+    @NotNull
     private static final LinkedHashMap<String, FuncEnum> map;
 
     static {
         map = new LinkedHashMap<>();
-        for (FuncEnum value : values()) {
+        for (@NotNull FuncEnum value : values()) {
             map.put(value.code, value);
         }
     }
diff --git a/src/main/java/io/github/linwancen/plugin/show/bean/LineInfo.java b/src/main/java/io/github/linwancen/plugin/show/bean/LineInfo.java
index 316ede5..9dba4d9 100644
--- a/src/main/java/io/github/linwancen/plugin/show/bean/LineInfo.java
+++ b/src/main/java/io/github/linwancen/plugin/show/bean/LineInfo.java
@@ -22,7 +22,7 @@ public class LineInfo extends FileInfo {
     }
 
     public static @Nullable LineInfo of(@NotNull VirtualFile file, @NotNull Project project, int lineNumber) {
-        FileInfo fileInfo = of(file, project);
+        @Nullable FileInfo fileInfo = of(file, project);
         if (fileInfo == null) {
             return null;
         }
@@ -40,7 +40,7 @@ public class LineInfo extends FileInfo {
             if (startOffset == endOffset) {
                 return null;
             }
-            String text = fileInfo.document.getText(new TextRange(startOffset, endOffset));
+            @NotNull String text = fileInfo.document.getText(new TextRange(startOffset, endOffset));
             return new LineInfo(fileInfo, text, lineNumber, startOffset, endOffset);
         } catch (Exception e) {
             return null;
diff --git a/src/main/java/io/github/linwancen/plugin/show/bean/SettingsInfo.java b/src/main/java/io/github/linwancen/plugin/show/bean/SettingsInfo.java
index fc8bb59..daf18ac 100644
--- a/src/main/java/io/github/linwancen/plugin/show/bean/SettingsInfo.java
+++ b/src/main/java/io/github/linwancen/plugin/show/bean/SettingsInfo.java
@@ -16,11 +16,12 @@ public class SettingsInfo {
         this.projectSettings = ProjectSettingsState.getInstance(project);
     }
 
-    public static @NotNull SettingsInfo of(@NotNull Project project, FuncEnum funcEnum) {
+    public static @NotNull SettingsInfo of(@NotNull Project project, @NotNull FuncEnum funcEnum) {
         return new SettingsInfo(project, funcEnum);
     }
 
     /** treeTags/lineTags */
+    @NotNull
     public String[] tagNames() {
         return funcEnum == FuncEnum.TREE
                 ? appSettings.treeTags
diff --git a/src/main/java/io/github/linwancen/plugin/show/ext/GetFromDocMap.java b/src/main/java/io/github/linwancen/plugin/show/ext/GetFromDocMap.java
index c01a4f3..62f4015 100644
--- a/src/main/java/io/github/linwancen/plugin/show/ext/GetFromDocMap.java
+++ b/src/main/java/io/github/linwancen/plugin/show/ext/GetFromDocMap.java
@@ -13,7 +13,7 @@ class GetFromDocMap {
 
     @Nullable
     static String get(@NotNull Map<String, Map<String, List<String>>> docMap, @NotNull String... words) {
-        List<String> keywordDoc = list(docMap, words);
+        @NotNull List<String> keywordDoc = list(docMap, words);
         if (keywordDoc.size() >= 2) {
             return keywordDoc.get(1);
         }
@@ -22,7 +22,7 @@ class GetFromDocMap {
 
     @NotNull
     private static List<String> list(@NotNull Map<String, Map<String, List<String>>> docMap, @NotNull String... words) {
-        for (Map.Entry<String, Map<String, List<String>>> entry : docMap.entrySet()) {
+        for (@NotNull Map.Entry<String, Map<String, List<String>>> entry : docMap.entrySet()) {
             Map<String, List<String>> map = entry.getValue();
             for (String word : words) {
                 List<String> wordDoc = map.get(word);
diff --git a/src/main/java/io/github/linwancen/plugin/show/ext/LineExt.java b/src/main/java/io/github/linwancen/plugin/show/ext/LineExt.java
index c09b64b..53c137b 100644
--- a/src/main/java/io/github/linwancen/plugin/show/ext/LineExt.java
+++ b/src/main/java/io/github/linwancen/plugin/show/ext/LineExt.java
@@ -16,8 +16,8 @@ public class LineExt {
 
     public static @Nullable String doc(@NotNull LineInfo lineInfo) {
         int i = lineInfo.text.indexOf(lineInfo.appSettings.lineEndPrefix);
-        String code = i <= 0 ? lineInfo.text : lineInfo.text.substring(0, i);
-        String extDoc = LineExt.extDoc(lineInfo, code);
+        @NotNull String code = i <= 0 ? lineInfo.text : lineInfo.text.substring(0, i);
+        @Nullable String extDoc = LineExt.extDoc(lineInfo, code);
         if (extDoc == null) {
             return null;
         }
@@ -28,20 +28,21 @@ public class LineExt {
         return extDoc;
     }
 
+    @Nullable
     public static String extDoc(@NotNull LineInfo lineInfo, @NotNull String code) {
-        String path = lineInfo.file.getPath();
-        String name = lineInfo.file.getName();
-        String ext = lineInfo.file.getExtension();
-        Map<String, Map<String, List<String>>> keyMap = ConfCache.keyMap(path, name, ext);
+        @NotNull String path = lineInfo.file.getPath();
+        @NotNull String name = lineInfo.file.getName();
+        @Nullable String ext = lineInfo.file.getExtension();
+        @NotNull Map<String, Map<String, List<String>>> keyMap = ConfCache.keyMap(path, name, ext);
         if (keyMap.isEmpty()) {
             return null;
         }
-        Pattern pattern = ConfCache.pattern(lineInfo.project, keyMap, path);
+        @Nullable Pattern pattern = ConfCache.pattern(lineInfo.project, keyMap, path);
         if (pattern == null || pattern.pattern().length() == 0) {
             return null;
         }
-        Map<String, Map<String, List<String>>> docMap = ConfCache.docMap(path, name, ext);
-        Map<String, Map<String, List<String>>> treeMap = ConfCache.treeMap(path, name, ext);
+        @NotNull Map<String, Map<String, List<String>>> docMap = ConfCache.docMap(path, name, ext);
+        @NotNull Map<String, Map<String, List<String>>> treeMap = ConfCache.treeMap(path, name, ext);
         if (docMap.isEmpty() && treeMap.isEmpty()) {
             return null;
         }
@@ -49,7 +50,7 @@ public class LineExt {
             code = cblNotAndOr(code);
         }
         String[] words = pattern.split(code);
-        Matcher matcher = pattern.matcher(code);
+        @NotNull Matcher matcher = pattern.matcher(code);
         return extDoc(keyMap, matcher, docMap, words, treeMap);
     }
 
@@ -57,12 +58,12 @@ public class LineExt {
     private static final Pattern AND_OR_PATTERN = Pattern.compile("(AND|OR) ?'");
 
     @NotNull
-    private static String cblNotAndOr(String text) {
+    private static String cblNotAndOr(@NotNull String text) {
         // maybe faster than regexp
         if (!text.contains("=")) {
             return text;
         }
-        Matcher matcher = DICT_PATTERN.matcher(text);
+        @NotNull Matcher matcher = DICT_PATTERN.matcher(text);
         if (!matcher.find()) {
             return text;
         }
@@ -81,13 +82,13 @@ public class LineExt {
                                  @NotNull Map<String, Map<String, List<String>>> treeMap) {
         boolean haveDoc = false;
         boolean haveKey = false;
-        StringBuilder sb = new StringBuilder();
-        for (String s : words) {
+        @NotNull StringBuilder sb = new StringBuilder();
+        for (@NotNull String s : words) {
             haveDoc |= appendDoc(sb, s, docMap, treeMap);
             haveKey = appendKeyDoc(sb, matcher, keyMap);
         }
         while (haveKey) {
-            haveKey =  appendKeyDoc(sb, matcher, keyMap);
+            haveKey = appendKeyDoc(sb, matcher, keyMap);
         }
         if (!haveDoc) {
             return null;
@@ -102,12 +103,12 @@ public class LineExt {
         if (word.length() == 0) {
             return false;
         }
-        String wordDoc = GetFromDocMap.get(docMap, word);
+        @Nullable String wordDoc = GetFromDocMap.get(docMap, word);
         if (wordDoc != null) {
             sb.append(wordDoc);
             return true;
         }
-        String treeDoc = GetFromDocMap.get(treeMap, word);
+        @Nullable String treeDoc = GetFromDocMap.get(treeMap, word);
         if (treeDoc != null) {
             sb.append(treeDoc);
             return true;
@@ -118,14 +119,14 @@ public class LineExt {
     }
 
     private static boolean appendKeyDoc(@NotNull StringBuilder sb,
-                                     @NotNull Matcher matcher,
-                                     @NotNull Map<String, Map<String, List<String>>> keyMap) {
+                                        @NotNull Matcher matcher,
+                                        @NotNull Map<String, Map<String, List<String>>> keyMap) {
         if (!matcher.find()) {
             return false;
         }
         String keyword = matcher.group();
         // "" if no doc
-        String keyDoc = GetFromDocMap.get(keyMap, keyword);
+        @Nullable String keyDoc = GetFromDocMap.get(keyMap, keyword);
         if (keyDoc != null) {
             sb.append(" ").append(keyDoc);
         }
diff --git a/src/main/java/io/github/linwancen/plugin/show/ext/TreeExt.java b/src/main/java/io/github/linwancen/plugin/show/ext/TreeExt.java
index 0bae0ae..8464246 100644
--- a/src/main/java/io/github/linwancen/plugin/show/ext/TreeExt.java
+++ b/src/main/java/io/github/linwancen/plugin/show/ext/TreeExt.java
@@ -13,21 +13,23 @@ public class TreeExt {
 
     private TreeExt() {}
 
-    public static @Nullable String doc(ProjectViewNode<?> node) {
-        VirtualFile file = node.getVirtualFile();
+    public static @Nullable String doc(@NotNull ProjectViewNode<?> node) {
+        @Nullable VirtualFile file = node.getVirtualFile();
         if (file == null) {
             return null;
         }
         return TreeExt.extDoc(file);
     }
 
+    @Nullable
     public static String extDoc(@NotNull VirtualFile file) {
-        Map<String, Map<String, List<String>>> docMap = ConfCache.treeMap(file.getPath(), file.getName(), file.getPath());
-        String[] words = {
+        @NotNull Map<String, Map<String, List<String>>> docMap = ConfCache.treeMap(
+                file.getPath(), file.getName(), file.getPath());
+        @NotNull String[] words = {
                 file.getName(),
                 file.getNameWithoutExtension(),
         };
-        String extDoc = GetFromDocMap.get(docMap, words);
+        @Nullable String extDoc = GetFromDocMap.get(docMap, words);
         if (extDoc == null) {
             return null;
         }
diff --git a/src/main/java/io/github/linwancen/plugin/show/ext/conf/ConfCache.java b/src/main/java/io/github/linwancen/plugin/show/ext/conf/ConfCache.java
index aea67c5..6d3c810 100644
--- a/src/main/java/io/github/linwancen/plugin/show/ext/conf/ConfCache.java
+++ b/src/main/java/io/github/linwancen/plugin/show/ext/conf/ConfCache.java
@@ -76,7 +76,7 @@ public class ConfCache {
         TREE_CACHE.clear();
     }
 
-    static void remove(@NotNull VirtualFile file, String name) {
+    static void remove(@NotNull VirtualFile file, @Nullable String name) {
         if (name != null) {
             int i = name.lastIndexOf('.');
             name = name.substring(0, i);
@@ -93,7 +93,7 @@ public class ConfCache {
     }
 
     static void copy(@NotNull VirtualFile file, @NotNull VirtualFile newFile) {
-        String name = file.getNameWithoutExtension();
+        @NotNull String name = file.getNameWithoutExtension();
         if (name.endsWith(KEY_MID_EXT)) {
             copyCache(file, newFile, KEY_CACHE);
         } else if (name.endsWith(DOC_MID_EXT)) {
@@ -117,9 +117,9 @@ public class ConfCache {
     static void loadAll(@NotNull Project project) {
         DumbService.getInstance(project).runReadActionInSmartMode(() ->
                 ApplicationManager.getApplication().runReadAction(() -> {
-                    Collection<VirtualFile> files = FilenameIndex.getAllFilesByExt(project, EXT);
-                    StringBuilder sb = new StringBuilder();
-                    for (VirtualFile file : files) {
+                    @NotNull Collection<VirtualFile> files = FilenameIndex.getAllFilesByExt(project, EXT);
+                    @NotNull StringBuilder sb = new StringBuilder();
+                    for (@NotNull VirtualFile file : files) {
                         load(project, file);
                         sb.append(file.getName()).append("\n");
                     }
@@ -139,16 +139,16 @@ public class ConfCache {
         if (!ConfCache.EXT.equals(file.getExtension())) {
             return;
         }
-        Document document = FileDocumentManager.getInstance().getDocument(file);
+        @Nullable Document document = FileDocumentManager.getInstance().getDocument(file);
         if (document == null) {
             return;
         }
-        String text = document.getText();
-        String name = file.getNameWithoutExtension();
+        @NotNull String text = document.getText();
+        @NotNull String name = file.getNameWithoutExtension();
         // this pattern would skip empty line
         String[] lines = LINE_PATTERN.split(text);
         if (name.endsWith(KEY_MID_EXT)) {
-            String matchName = name.substring(0, name.length() - KEY_MID_EXT.length());
+            @NotNull String matchName = name.substring(0, name.length() - KEY_MID_EXT.length());
             int i = matchName.lastIndexOf(".");
             if (i > 0) {
                 EXT_IN_KEY_CACHE.add(matchName.substring(i + 1));
diff --git a/src/main/java/io/github/linwancen/plugin/show/ext/conf/ConfCacheGetUtils.java b/src/main/java/io/github/linwancen/plugin/show/ext/conf/ConfCacheGetUtils.java
index 20130ff..0c4c79e 100644
--- a/src/main/java/io/github/linwancen/plugin/show/ext/conf/ConfCacheGetUtils.java
+++ b/src/main/java/io/github/linwancen/plugin/show/ext/conf/ConfCacheGetUtils.java
@@ -32,13 +32,13 @@ class ConfCacheGetUtils {
     static <T> TreeMap<String, T> filterPathNameExt(@NotNull String confMidExt,
                                                     @NotNull Map<VirtualFile, T> cache,
                                                     @NotNull String path, @NotNull String name, @Nullable String ext) {
-        TreeMap<String, T> map = new TreeMap<>();
+        @NotNull TreeMap<String, T> map = new TreeMap<>();
         int max = path.length();
         int length = String.valueOf(max).length();
-        for (Map.Entry<VirtualFile, T> entry : cache.entrySet()) {
+        for (@NotNull Map.Entry<VirtualFile, T> entry : cache.entrySet()) {
             VirtualFile confFile = entry.getKey();
-            String confName = confFile.getNameWithoutExtension();
-            String confPath = confFile.getPath();
+            @NotNull String confName = confFile.getNameWithoutExtension();
+            @NotNull String confPath = confFile.getPath();
             int level = level(path, confPath);
             if (level == 0) {
                 continue;
@@ -76,12 +76,12 @@ class ConfCacheGetUtils {
     static <T> TreeMap<String, T> filterPath(@SuppressWarnings("SameParameterValue")
                                              @NotNull Map<VirtualFile, T> cache,
                                              @NotNull String path, String name, String ext) {
-        TreeMap<String, T> map = new TreeMap<>();
+        @NotNull TreeMap<String, T> map = new TreeMap<>();
         int max = path.length();
         int length = String.valueOf(max).length();
-        for (Map.Entry<VirtualFile, T> entry : cache.entrySet()) {
+        for (@NotNull Map.Entry<VirtualFile, T> entry : cache.entrySet()) {
             VirtualFile confFile = entry.getKey();
-            String confPath = confFile.getPath();
+            @NotNull String confPath = confFile.getPath();
             int level = level(path, confPath);
             if (level == 0) {
                 continue;
@@ -119,7 +119,7 @@ class ConfCacheGetUtils {
     }
 
     @NotNull
-    private static String srcPath(String path) {
+    private static String srcPath(@NotNull String path) {
         int i = path.indexOf('!');
         if (i != -1) {
             return path.substring(i + 1);
@@ -131,7 +131,7 @@ class ConfCacheGetUtils {
         return path;
     }
 
-    private static boolean match(String path, String confPath) {
+    private static boolean match(@NotNull String path, @NotNull String confPath) {
         if (confPath.equals(path) || SKIP_PATH.equals(confPath)) {
             return true;
         }
diff --git a/src/main/java/io/github/linwancen/plugin/show/ext/conf/ConfFactory.java b/src/main/java/io/github/linwancen/plugin/show/ext/conf/ConfFactory.java
index 84bba8d..effffce 100644
--- a/src/main/java/io/github/linwancen/plugin/show/ext/conf/ConfFactory.java
+++ b/src/main/java/io/github/linwancen/plugin/show/ext/conf/ConfFactory.java
@@ -29,11 +29,11 @@ class ConfFactory {
     @Nullable
     static Pattern buildPattern(@Nullable Project project, @NotNull String path,
                                 @NotNull Map<String, Map<String, List<String>>> map) {
-        Set<String> exclude = new LinkedSet<>();
-        StringBuilder sb = new StringBuilder();
-        for (Map<String, List<String>> keyMap : map.values()) {
+        @NotNull Set<String> exclude = new LinkedSet<>();
+        @NotNull StringBuilder sb = new StringBuilder();
+        for (@NotNull Map<String, List<String>> keyMap : map.values()) {
             // key() is escape
-            for (List<String> list : keyMap.values()) {
+            for (@NotNull List<String> list : keyMap.values()) {
                 String key = list.get(0);
                 if (key.startsWith("?")) {
                     exclude.add(key.substring(1));
@@ -45,7 +45,7 @@ class ConfFactory {
         if (sb.length() > 0) {
             sb.delete(sb.length() - 1, sb.length());
         }
-        String regex = sb.toString();
+        @NotNull String regex = sb.toString();
         Pattern pattern = PATTERN_CACHE.get(regex);
         if (pattern != null) {
             return pattern;
@@ -54,7 +54,7 @@ class ConfFactory {
         sb.insert(0, path);
         sb.insert(0, "\n");
         try {
-            Pattern compile = Pattern.compile(regex);
+            @NotNull Pattern compile = Pattern.compile(regex);
             PATTERN_CACHE.put(regex, compile);
             REGEXP_LOG.createNotification("Ext doc keyword regexp compile success", regex.length() + " chars",
                     sb.toString(), NotificationType.INFORMATION).notify(project);
@@ -74,9 +74,9 @@ class ConfFactory {
     @NotNull
     static Map<String, List<String>> buildMap(@Nullable Project project, @NotNull String path,
                                               @NotNull String[] lines, boolean isKey) {
-        Map<String, List<String>> map = new LinkedHashMap<>();
-        for (String line : lines) {
-            List<String> words = Splitter.on('\t').splitToList(line);
+        @NotNull Map<String, List<String>> map = new LinkedHashMap<>();
+        for (@NotNull String line : lines) {
+            @NotNull List<String> words = Splitter.on('\t').splitToList(line);
             if (!words.isEmpty()) {
                 String key = words.get(0);
                 if (key.length() == 0) {
diff --git a/src/main/java/io/github/linwancen/plugin/show/ext/conf/ConfFileChangeListener.java b/src/main/java/io/github/linwancen/plugin/show/ext/conf/ConfFileChangeListener.java
index fc802a8..0f13696 100644
--- a/src/main/java/io/github/linwancen/plugin/show/ext/conf/ConfFileChangeListener.java
+++ b/src/main/java/io/github/linwancen/plugin/show/ext/conf/ConfFileChangeListener.java
@@ -4,6 +4,7 @@ import com.intellij.openapi.fileEditor.FileEditorManagerEvent;
 import com.intellij.openapi.fileEditor.FileEditorManagerListener;
 import com.intellij.openapi.vfs.VirtualFile;
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 
 /**
  * call ConfCache.loadFile
@@ -12,7 +13,7 @@ public class ConfFileChangeListener implements FileEditorManagerListener {
 
     @Override
     public void selectionChanged(@NotNull FileEditorManagerEvent event) {
-        VirtualFile file = event.getOldFile();
+        @Nullable VirtualFile file = event.getOldFile();
         if (file == null) {
             return;
         }
diff --git a/src/main/java/io/github/linwancen/plugin/show/ext/conf/ConfFileListener.java b/src/main/java/io/github/linwancen/plugin/show/ext/conf/ConfFileListener.java
index a5cde1f..7e44182 100644
--- a/src/main/java/io/github/linwancen/plugin/show/ext/conf/ConfFileListener.java
+++ b/src/main/java/io/github/linwancen/plugin/show/ext/conf/ConfFileListener.java
@@ -4,6 +4,7 @@ import com.intellij.openapi.vfs.VirtualFile;
 import com.intellij.openapi.vfs.newvfs.BulkFileListener;
 import com.intellij.openapi.vfs.newvfs.events.*;
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 
 import java.util.List;
 
@@ -14,18 +15,18 @@ public class ConfFileListener implements BulkFileListener {
 
     @Override
     public void after(@NotNull List<? extends VFileEvent> events) {
-        for (VFileEvent event : events) {
+        for (@NotNull VFileEvent event : events) {
             forEvent(event);
         }
     }
 
-    private static void forEvent(VFileEvent event) {
-        VirtualFile file = event.getFile();
+    private static void forEvent(@NotNull VFileEvent event) {
+        @Nullable VirtualFile file = event.getFile();
         if (file == null) {
             return;
         }
         if (event instanceof VFilePropertyChangeEvent) {
-            VFilePropertyChangeEvent changeEvent = (VFilePropertyChangeEvent) event;
+            @NotNull VFilePropertyChangeEvent changeEvent = (VFilePropertyChangeEvent) event;
             if ("name".equals(changeEvent.getPropertyName())) {
                 String oldName = changeEvent.getOldValue().toString();
                 if (oldName.endsWith(ConfCache.EXT)) {
@@ -45,8 +46,8 @@ public class ConfFileListener implements BulkFileListener {
             return;
         }
         if (event instanceof VFileCopyEvent) {
-            VFileCopyEvent copyEvent = (VFileCopyEvent) event;
-            VirtualFile newFile = copyEvent.findCreatedFile();
+            @NotNull VFileCopyEvent copyEvent = (VFileCopyEvent) event;
+            @Nullable VirtualFile newFile = copyEvent.findCreatedFile();
             if (newFile == null) {
                 return;
             }
diff --git a/src/main/java/io/github/linwancen/plugin/show/ext/conf/ReloadExtDocAction.java b/src/main/java/io/github/linwancen/plugin/show/ext/conf/ReloadExtDocAction.java
index 4272c72..9d9fd06 100644
--- a/src/main/java/io/github/linwancen/plugin/show/ext/conf/ReloadExtDocAction.java
+++ b/src/main/java/io/github/linwancen/plugin/show/ext/conf/ReloadExtDocAction.java
@@ -4,6 +4,7 @@ import com.intellij.openapi.actionSystem.AnAction;
 import com.intellij.openapi.actionSystem.AnActionEvent;
 import com.intellij.openapi.project.Project;
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 
 /**
  * call ConfCache.loadAll
@@ -11,7 +12,7 @@ import org.jetbrains.annotations.NotNull;
 public class ReloadExtDocAction extends AnAction {
     @Override
     public void actionPerformed(@NotNull AnActionEvent e) {
-        Project project = e.getProject();
+        @Nullable Project project = e.getProject();
         if (project == null) {
             return;
         }
diff --git a/src/main/java/io/github/linwancen/plugin/show/jump/JsonRef.java b/src/main/java/io/github/linwancen/plugin/show/jump/JsonRef.java
index b34df07..de127cd 100644
--- a/src/main/java/io/github/linwancen/plugin/show/jump/JsonRef.java
+++ b/src/main/java/io/github/linwancen/plugin/show/jump/JsonRef.java
@@ -8,7 +8,9 @@ import java.util.List;
 
 public class JsonRef<T extends PsiElement> extends PsiReferenceBase<PsiElement> implements PsiPolyVariantReference {
 
+    @NotNull
     final T psiField;
+    @NotNull
     final List<T> tips;
 
     public JsonRef(@NotNull PsiElement element, @NotNull T psiField, @NotNull List<T> tips) {
diff --git a/src/main/java/io/github/linwancen/plugin/show/lang/GoLangDoc.java b/src/main/java/io/github/linwancen/plugin/show/lang/GoLangDoc.java
index 23832d6..3b76728 100644
--- a/src/main/java/io/github/linwancen/plugin/show/lang/GoLangDoc.java
+++ b/src/main/java/io/github/linwancen/plugin/show/lang/GoLangDoc.java
@@ -31,7 +31,7 @@ public class GoLangDoc extends BaseLangDoc {
 
     @Override
     public @Nullable <T extends SettingsInfo> String resolveDocRaw(@NotNull T lineInfo, @NotNull PsiElement resolve) {
-        List<PsiComment> comments = GoDocumentationProvider.getCommentsForElement(resolve);
+        @NotNull List<PsiComment> comments = GoDocumentationProvider.getCommentsForElement(resolve);
         return GoDocumentationProvider.getCommentText(comments, false);
     }
 }
diff --git a/src/main/java/io/github/linwancen/plugin/show/lang/JsLangDoc.java b/src/main/java/io/github/linwancen/plugin/show/lang/JsLangDoc.java
index 7ad174b..30ce8d8 100644
--- a/src/main/java/io/github/linwancen/plugin/show/lang/JsLangDoc.java
+++ b/src/main/java/io/github/linwancen/plugin/show/lang/JsLangDoc.java
@@ -29,12 +29,12 @@ public class JsLangDoc extends BaseLangDoc {
 
     @Override
     public @Nullable <T extends SettingsInfo> String resolveDocRaw(@NotNull T lineInfo, @NotNull PsiElement resolve) {
-        PsiComment psiComment = JSDocumentationUtils.findOwnDocCommentForImplicitElement(resolve);
+        @Nullable PsiComment psiComment = JSDocumentationUtils.findOwnDocCommentForImplicitElement(resolve);
         if (psiComment == null) {
             return null;
         }
         String text = psiComment.getText();
-        if (text!=null) {
+        if (text != null) {
             return text;
         }
         if (!lineInfo.appSettings.jsDoc) {
diff --git a/src/main/java/io/github/linwancen/plugin/show/lang/JsonLangDoc.java b/src/main/java/io/github/linwancen/plugin/show/lang/JsonLangDoc.java
index 789053e..5dd737e 100644
--- a/src/main/java/io/github/linwancen/plugin/show/lang/JsonLangDoc.java
+++ b/src/main/java/io/github/linwancen/plugin/show/lang/JsonLangDoc.java
@@ -25,7 +25,7 @@ public class JsonLangDoc extends BaseLangDoc {
 
     @Override
     public @Nullable String findRefDoc(@NotNull LineInfo lineInfo, @NotNull PsiElement element) {
-        PsiElement start = lineInfo.viewProvider.findElementAt(lineInfo.startOffset);
+        @Nullable PsiElement start = lineInfo.viewProvider.findElementAt(lineInfo.startOffset);
         if (start == null) {
             return null;
         }
@@ -41,10 +41,10 @@ public class JsonLangDoc extends BaseLangDoc {
         if (!(ref instanceof JsonProperty)) {
             return null;
         }
-        JsonProperty jsonProperty = (JsonProperty) ref;
-        PsiReference[] references = jsonProperty.getNameElement().getReferences();
-        for (PsiReference reference : references) {
-            PsiElement resolve = null;
+        @NotNull JsonProperty jsonProperty = (JsonProperty) ref;
+        @NotNull PsiReference[] references = jsonProperty.getNameElement().getReferences();
+        for (@NotNull PsiReference reference : references) {
+            @Nullable PsiElement resolve = null;
             try {
                 resolve = reference.resolve();
             } catch (Throwable ignore) {
@@ -53,7 +53,7 @@ public class JsonLangDoc extends BaseLangDoc {
             if (resolve == null) {
                 continue;
             }
-            String doc = BaseLangDoc.resolveDoc(lineInfo, resolve);
+            @Nullable String doc = BaseLangDoc.resolveDoc(lineInfo, resolve);
             if (doc != null) {
                 return doc;
             }
diff --git a/src/main/java/io/github/linwancen/plugin/show/lang/SqlLangDoc.java b/src/main/java/io/github/linwancen/plugin/show/lang/SqlLangDoc.java
index f6bf7a1..585cc8f 100644
--- a/src/main/java/io/github/linwancen/plugin/show/lang/SqlLangDoc.java
+++ b/src/main/java/io/github/linwancen/plugin/show/lang/SqlLangDoc.java
@@ -39,8 +39,8 @@ public class SqlLangDoc extends BaseLangDoc {
         } catch (Throwable e) {
             return null;
         }
-        for (DbElement dbElement : relatedDbElements) {
-            String refDoc = dbElement.getComment();
+        for (@NotNull DbElement dbElement : relatedDbElements) {
+            @Nullable String refDoc = dbElement.getComment();
             if (refDoc != null && !DocSkip.skipDoc(lineInfo.appSettings, lineInfo.projectSettings, refDoc)) {
                 return refDoc;
             }
diff --git a/src/main/java/io/github/linwancen/plugin/show/lang/base/BaseLangDoc.java b/src/main/java/io/github/linwancen/plugin/show/lang/base/BaseLangDoc.java
index 9d68596..99adab5 100644
--- a/src/main/java/io/github/linwancen/plugin/show/lang/base/BaseLangDoc.java
+++ b/src/main/java/io/github/linwancen/plugin/show/lang/base/BaseLangDoc.java
@@ -41,7 +41,7 @@ public abstract class BaseLangDoc extends EditorLinePainter {
     }
 
     public static @Nullable String langDoc(@NotNull LineInfo lineInfo) {
-        PsiElement element = lineInfo.viewProvider.findElementAt(lineInfo.endOffset);
+        @Nullable PsiElement element = lineInfo.viewProvider.findElementAt(lineInfo.endOffset);
         if (element == null) {
             // file end
             element = lineInfo.viewProvider.findElementAt(lineInfo.endOffset - 1);
@@ -49,7 +49,7 @@ public abstract class BaseLangDoc extends EditorLinePainter {
                 return null;
             }
         }
-        Language language = PsiElementTo.language(element);
+        @NotNull Language language = PsiElementTo.language(element);
         BaseLangDoc lineEnd = LANG_DOC_MAP.get(language.getID());
         if (lineEnd != null && lineEnd.show(lineInfo)) {
             return lineEnd.findRefDoc(lineInfo, element);
@@ -64,15 +64,15 @@ public abstract class BaseLangDoc extends EditorLinePainter {
      */
     @Nullable
     public String findRefDoc(@NotNull LineInfo lineInfo, @NotNull PsiElement element) {
-        Class<? extends PsiElement> refClass = getRefClass();
+        @Nullable Class<? extends PsiElement> refClass = getRefClass();
         if (refClass == null) {
             return null;
         }
-        String doc = null;
-        PsiElement refElement = element;
+        @Nullable String doc = null;
+        @Nullable PsiElement refElement = element;
         while ((refElement = Prev.prevRefChild(lineInfo, refElement, refClass)) != null) {
             PsiElement parent = refElement.getParent();
-            String filterDoc = refElementDoc(lineInfo, parent);
+            @Nullable String filterDoc = refElementDoc(lineInfo, parent);
             if (filterDoc != null) {
                 doc = filterDoc;
                 refElement = parent;
@@ -90,7 +90,7 @@ public abstract class BaseLangDoc extends EditorLinePainter {
         String text = refElement.getText();
         boolean set = text.startsWith("set");
         PsiElement parent = refElement.getParent();
-        String before = refElementDoc(lineInfo, parent);
+        @Nullable String before = refElementDoc(lineInfo, parent);
         if (before != null) {
             doc = mergeDoc(set, lineInfo.appSettings.getToSet, before, doc);
         }
@@ -115,9 +115,10 @@ public abstract class BaseLangDoc extends EditorLinePainter {
     /**
      * Override like SQL
      */
+    @Nullable
     protected <T extends SettingsInfo> String refElementDoc(@NotNull T lineInfo,
                                                             @NotNull PsiElement refElement) {
-        String refDoc = refDoc(lineInfo, refElement);
+        @Nullable String refDoc = refDoc(lineInfo, refElement);
         if (refDoc != null && !DocSkip.skipDoc(lineInfo.appSettings, lineInfo.projectSettings, refDoc)) {
             return refDoc;
         }
@@ -130,22 +131,23 @@ public abstract class BaseLangDoc extends EditorLinePainter {
     @Nullable
     protected <T extends SettingsInfo> String refDoc(@NotNull T lineInfo, @NotNull PsiElement ref) {
         // kotlin ref.getReference() == null but ref.getReferences().length == 2
-        PsiReference[] references = ref.getReferences();
+        @NotNull PsiReference[] references = ref.getReferences();
         if (references.length < 1) {
             return null;
         }
-        for (PsiReference reference : references) {
-            PsiElement resolve;
+        for (@NotNull PsiReference reference : references) {
+            @Nullable PsiElement resolve;
             try {
                 resolve = reference.resolve();
             } catch (Throwable e) {
-                // 2021.3: Slow operations are prohibited on EDT. See SlowOperations.assertSlowOperationsAreAllowed javadoc.
+                // 2021.3: Slow operations are prohibited on EDT.
+                // See SlowOperations.assertSlowOperationsAreAllowed javadoc.
                 return null;
             }
             if (resolve == null) {
                 return null;
             }
-            String resolveDoc = resolveDoc(lineInfo, resolve);
+            @Nullable String resolveDoc = resolveDoc(lineInfo, resolve);
             if (resolveDoc != null) {
                 return resolveDoc;
             }
@@ -153,9 +155,10 @@ public abstract class BaseLangDoc extends EditorLinePainter {
         return null;
     }
 
-    public static @Nullable <T extends SettingsInfo> String resolveDoc(T settingsInfo, PsiElement psiElement) {
+    public static @Nullable <T extends SettingsInfo> String resolveDoc(@NotNull T settingsInfo,
+                                                                       @NotNull PsiElement psiElement) {
         // support like java <-> kotlin
-        Language language = PsiElementTo.language(psiElement);
+        @NotNull Language language = PsiElementTo.language(psiElement);
         BaseLangDoc lineEnd = LANG_DOC_MAP.get(language.getID());
         if (lineEnd == null) {
             return null;
@@ -168,12 +171,12 @@ public abstract class BaseLangDoc extends EditorLinePainter {
      */
     @Nullable
     protected <T extends SettingsInfo> String resolveDocPrint(@NotNull T lineInfo, @NotNull PsiElement resolve) {
-        String s = resolveDocRaw(lineInfo, resolve);
+        @Nullable String s = resolveDocRaw(lineInfo, resolve);
         if (s == null) {
             return null;
         }
-        String cutDoc = DocFilter.cutDoc(s, lineInfo.appSettings, true);
-        String filterDoc = DocFilter.filterDoc(cutDoc, lineInfo.appSettings, lineInfo.projectSettings);
+        @NotNull String cutDoc = DocFilter.cutDoc(s, lineInfo.appSettings, true);
+        @NotNull String filterDoc = DocFilter.filterDoc(cutDoc, lineInfo.appSettings, lineInfo.projectSettings);
         if (filterDoc.trim().length() == 0) {
             return null;
         }
@@ -185,17 +188,18 @@ public abstract class BaseLangDoc extends EditorLinePainter {
      */
     @Nullable
     protected <T extends SettingsInfo> String resolveDocRaw(@NotNull T lineInfo, @NotNull PsiElement resolve) {
-        FileViewProvider viewProvider = PsiElementTo.viewProvider(resolve);
+        @Nullable FileViewProvider viewProvider = PsiElementTo.viewProvider(resolve);
         if (viewProvider == null) {
             return null;
         }
-        String doc = ResolveDoc.fromLineEnd(lineInfo, resolve, viewProvider);
+        @Nullable String doc = ResolveDoc.fromLineEnd(lineInfo, resolve, viewProvider);
         if (doc != null) {
             return doc;
         }
         return ResolveDoc.fromLineUp(lineInfo, resolve, viewProvider, keywords());
     }
 
+    @NotNull
     protected List<String> keywords() {
         return Collections.emptyList();
     }
diff --git a/src/main/java/io/github/linwancen/plugin/show/lang/base/BaseTagLangDoc.java b/src/main/java/io/github/linwancen/plugin/show/lang/base/BaseTagLangDoc.java
index b701fb5..c027387 100644
--- a/src/main/java/io/github/linwancen/plugin/show/lang/base/BaseTagLangDoc.java
+++ b/src/main/java/io/github/linwancen/plugin/show/lang/base/BaseTagLangDoc.java
@@ -9,7 +9,7 @@ public abstract class BaseTagLangDoc<DocElement> extends BaseLangDoc {
 
     @Override
     public @Nullable <T extends SettingsInfo> String resolveDocPrint(@NotNull T lineInfo, @NotNull PsiElement resolve) {
-        DocElement docElement = toDocElement(resolve);
+        @Nullable DocElement docElement = toDocElement(resolve);
         if (docElement == null) {
             return null;
         }
@@ -22,12 +22,12 @@ public abstract class BaseTagLangDoc<DocElement> extends BaseLangDoc {
             return null;
         }
         // desc
-        String descDoc = descDoc(lineInfo, docElement).trim();
-        String desc = DocFilter.filterDoc(descDoc, lineInfo.appSettings, lineInfo.projectSettings);
+        @NotNull String descDoc = descDoc(lineInfo, docElement).trim();
+        @NotNull String desc = DocFilter.filterDoc(descDoc, lineInfo.appSettings, lineInfo.projectSettings);
         // tag
-        StringBuilder tagStrBuilder = new StringBuilder();
-        String[] names = lineInfo.tagNames();
-        for (String name : names) {
+        @NotNull StringBuilder tagStrBuilder = new StringBuilder();
+        @NotNull String[] names = lineInfo.tagNames();
+        for (@NotNull String name : names) {
             appendTag(lineInfo, tagStrBuilder, docElement, name);
         }
         if (desc.length() > 0) {
@@ -36,7 +36,7 @@ public abstract class BaseTagLangDoc<DocElement> extends BaseLangDoc {
             }
             tagStrBuilder.insert(0, desc);
         }
-        String text = tagStrBuilder.toString().trim();
+        @NotNull String text = tagStrBuilder.toString().trim();
         if (text.length() == 0) {
             return null;
         }
diff --git a/src/main/java/io/github/linwancen/plugin/show/lang/base/DocFilter.java b/src/main/java/io/github/linwancen/plugin/show/lang/base/DocFilter.java
index 0ff93a9..088a7b3 100644
--- a/src/main/java/io/github/linwancen/plugin/show/lang/base/DocFilter.java
+++ b/src/main/java/io/github/linwancen/plugin/show/lang/base/DocFilter.java
@@ -3,7 +3,6 @@ package io.github.linwancen.plugin.show.lang.base;
 import io.github.linwancen.plugin.show.settings.AppSettingsState;
 import io.github.linwancen.plugin.show.settings.ProjectSettingsState;
 import org.jetbrains.annotations.NotNull;
-import org.jetbrains.annotations.Nullable;
 
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
@@ -33,10 +32,10 @@ public class DocFilter {
      */
     @NotNull
     public static String cutDoc(String text,
-                                AppSettingsState appSettings, boolean deletePrefix) {
+                                @NotNull AppSettingsState appSettings, boolean deletePrefix) {
         String[] split = LINE_SEPARATOR_PATTERN.split(text);
         int lineCount = 0;
-        StringBuilder sb = new StringBuilder();
+        @NotNull StringBuilder sb = new StringBuilder();
         for (String s : split) {
             if (deletePrefix) {
                 s = DOC_PATTERN.matcher(s).replaceAll("");
@@ -64,8 +63,8 @@ public class DocFilter {
      */
     @NotNull
     public static String filterDoc(@NotNull String text,
-                                   AppSettingsState appSettings,
-                                   ProjectSettingsState projectSettings) {
+                                   @NotNull AppSettingsState appSettings,
+                                   @NotNull ProjectSettingsState projectSettings) {
         // docGetEffect first because default false
         if (projectSettings.docGetEffect && projectSettings.projectFilterEffective) {
             return filterDoc(text, projectSettings.docGet);
@@ -79,7 +78,7 @@ public class DocFilter {
     @NotNull
     public static String filterDoc(@NotNull String text, @NotNull Pattern docGet) {
         // if effect skip check empty
-        Matcher m = docGet.matcher(text);
+        @NotNull Matcher m = docGet.matcher(text);
         if (m.find()) {
             return m.group(m.groupCount());
         }
@@ -93,7 +92,7 @@ public class DocFilter {
      * trim end with space
      */
     public static void addHtml(@NotNull StringBuilder sb, @NotNull String s) {
-        String deleteHtml = HTML_PATTERN.matcher(s).replaceAll("").trim();
+        @NotNull String deleteHtml = HTML_PATTERN.matcher(s).replaceAll("").trim();
         if (deleteHtml.length() > 0) {
             sb.append(deleteHtml).append(" ");
         }
diff --git a/src/main/java/io/github/linwancen/plugin/show/lang/base/DocSkip.java b/src/main/java/io/github/linwancen/plugin/show/lang/base/DocSkip.java
index 4bc531f..c60b61f 100644
--- a/src/main/java/io/github/linwancen/plugin/show/lang/base/DocSkip.java
+++ b/src/main/java/io/github/linwancen/plugin/show/lang/base/DocSkip.java
@@ -3,6 +3,7 @@ package io.github.linwancen.plugin.show.lang.base;
 import io.github.linwancen.plugin.show.settings.AppSettingsState;
 import io.github.linwancen.plugin.show.settings.ProjectSettingsState;
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 
 import java.util.regex.Pattern;
 
@@ -10,7 +11,8 @@ public class DocSkip {
 
     private DocSkip() {}
 
-    public static boolean skipSign(AppSettingsState appSettings, ProjectSettingsState projectSettings, String text) {
+    public static boolean skipSign(@NotNull AppSettingsState appSettings,
+                                   @NotNull ProjectSettingsState projectSettings, String text) {
         return skipText(text,
                 projectSettings.globalFilterEffective, appSettings.lineInclude, appSettings.lineExclude,
                 projectSettings.projectFilterEffective, projectSettings.lineInclude, projectSettings.lineExclude);
@@ -18,7 +20,8 @@ public class DocSkip {
 
     private static final Pattern NOT_ASCII_PATTERN = Pattern.compile("[^\u0000-\u007f]");
 
-    public static boolean skipDoc(AppSettingsState appSettings, ProjectSettingsState projectSettings, String text) {
+    public static boolean skipDoc(@NotNull AppSettingsState appSettings,
+                                  @NotNull ProjectSettingsState projectSettings, @NotNull String text) {
         if (appSettings.skipAscii && !NOT_ASCII_PATTERN.matcher(text).find()) {
             return true;
         }
@@ -27,9 +30,10 @@ public class DocSkip {
                 projectSettings.projectFilterEffective, projectSettings.docInclude, projectSettings.docExclude);
     }
 
-    static boolean skipText(String text,
-                            boolean appFilterEffective, Pattern appDocInclude, Pattern appDocExclude,
-                            boolean projectFilterEffective, Pattern projectDocInclude, Pattern projectDocExclude
+    static boolean skipText(@Nullable String text,
+                            boolean appFilterEffective, @NotNull Pattern appDocInclude, @NotNull Pattern appDocExclude,
+                            boolean projectFilterEffective, @NotNull Pattern projectDocInclude,
+                            @NotNull Pattern projectDocExclude
     ) {
         if (text == null) {
             return true;
@@ -44,21 +48,21 @@ public class DocSkip {
         return false;
     }
 
-    static boolean skipText(@NotNull String text, Pattern include, Pattern exclude) {
+    static boolean skipText(@NotNull String text, @NotNull Pattern include, @NotNull Pattern exclude) {
         if (exclude(text, exclude)) {
             return true;
         }
         return !include(text, include);
     }
 
-    static boolean include(@NotNull String text, Pattern include) {
+    static boolean include(@NotNull String text, @NotNull Pattern include) {
         if (include.pattern().length() == 0) {
             return true;
         }
         return include.matcher(text).find();
     }
 
-    static boolean exclude(@NotNull String text, Pattern exclude) {
+    static boolean exclude(@NotNull String text, @NotNull Pattern exclude) {
         if (exclude.pattern().length() == 0) {
             return false;
         }
diff --git a/src/main/java/io/github/linwancen/plugin/show/lang/base/Prev.java b/src/main/java/io/github/linwancen/plugin/show/lang/base/Prev.java
index 25d00c7..8fdc0ed 100644
--- a/src/main/java/io/github/linwancen/plugin/show/lang/base/Prev.java
+++ b/src/main/java/io/github/linwancen/plugin/show/lang/base/Prev.java
@@ -15,6 +15,7 @@ public class Prev {
 
     private Prev() {}
 
+    @Nullable
     public static PsiElement prevRefChild(@NotNull LineInfo lineInfo, @NotNull PsiElement element,
                                           @NotNull Class<? extends PsiElement> refClass) {
         PsiElement prevParent = element.getParent();
@@ -22,7 +23,7 @@ public class Prev {
             if (element.getTextRange().getEndOffset() < lineInfo.startOffset) {
                 return null;
             }
-            PsiElement parent = refClassParent(element, refClass);
+            @Nullable PsiElement parent = refClassParent(element, refClass);
             if (parent != null) {
                 // skip b in a.b.c
                 if (prevParent.getTextRange().getEndOffset() < lineInfo.endOffset
@@ -42,6 +43,7 @@ public class Prev {
             "{-~" +
             "]++");
 
+    @Nullable
     private static PsiElement refClassParent(@NotNull PsiElement element,
                                              @NotNull Class<? extends PsiElement> refClass) {
         String text = element.getText();
@@ -67,7 +69,7 @@ public class Prev {
 
     public static @Nullable <T extends SettingsInfo> PsiElement prevCompactElement(
             @SuppressWarnings("unused") @NotNull T lineInfo, @NotNull PsiElement resolve, @NotNull Document document) {
-        PsiElement element = PsiTreeUtil.prevVisibleLeaf(resolve);
+        @Nullable PsiElement element = PsiTreeUtil.prevVisibleLeaf(resolve);
         if (element == null) {
             return null;
         }
@@ -79,7 +81,7 @@ public class Prev {
         } catch (Exception e) {
             return null;
         }
-        String replace = spaceText.replace("\n", "");
+        @NotNull String replace = spaceText.replace("\n", "");
         if (spaceText.length() - replace.length() > 1) {
             return null;
         }
diff --git a/src/main/java/io/github/linwancen/plugin/show/lang/base/PsiElementTo.java b/src/main/java/io/github/linwancen/plugin/show/lang/base/PsiElementTo.java
index a0f59a7..6c8c841 100644
--- a/src/main/java/io/github/linwancen/plugin/show/lang/base/PsiElementTo.java
+++ b/src/main/java/io/github/linwancen/plugin/show/lang/base/PsiElementTo.java
@@ -13,7 +13,7 @@ public class PsiElementTo {
 
     private PsiElementTo() {}
 
-    public static @Nullable FileViewProvider viewProvider(PsiElement resolve) {
+    public static @Nullable FileViewProvider viewProvider(@NotNull PsiElement resolve) {
         PsiFile psiFile = resolve.getContainingFile();
         if (psiFile == null) {
             return null;
@@ -26,8 +26,8 @@ public class PsiElementTo {
     }
 
     public static @NotNull Language language(@NotNull PsiElement element) {
-        Language lang = element.getLanguage();
-        Language base = lang.getBaseLanguage();
+        @NotNull Language lang = element.getLanguage();
+        @Nullable Language base = lang.getBaseLanguage();
         if (base != null) {
             return base;
         }
diff --git a/src/main/java/io/github/linwancen/plugin/show/lang/base/ResolveDoc.java b/src/main/java/io/github/linwancen/plugin/show/lang/base/ResolveDoc.java
index dff973d..83c8385 100644
--- a/src/main/java/io/github/linwancen/plugin/show/lang/base/ResolveDoc.java
+++ b/src/main/java/io/github/linwancen/plugin/show/lang/base/ResolveDoc.java
@@ -19,7 +19,7 @@ public class ResolveDoc {
     public static <T extends SettingsInfo> String fromLineEnd(@SuppressWarnings("unused") @NotNull T lineInfo,
                                                               @NotNull PsiElement resolve,
                                                               @NotNull FileViewProvider resolveViewProvider) {
-        Document document = resolveViewProvider.getDocument();
+        @Nullable Document document = resolveViewProvider.getDocument();
         if (document == null) {
             return null;
         }
@@ -33,11 +33,11 @@ public class ResolveDoc {
             return null;
         }
         // end over will return last
-        PsiElement psiElement = resolveViewProvider.findElementAt(resolveEndOffset);
+        @Nullable PsiElement psiElement = resolveViewProvider.findElementAt(resolveEndOffset);
         if (psiElement == null) {
             return null;
         }
-        PsiElement docElement = PsiTreeUtil.prevVisibleLeaf(psiElement);
+        @Nullable PsiElement docElement = PsiTreeUtil.prevVisibleLeaf(psiElement);
         if (!(docElement instanceof PsiComment)) {
             return null;
         }
@@ -51,14 +51,14 @@ public class ResolveDoc {
 
     @Nullable
     public static <T extends SettingsInfo> String fromLineUp(@NotNull T lineInfo,
-                                                             PsiElement resolve,
+                                                             @NotNull PsiElement resolve,
                                                              @NotNull FileViewProvider resolveViewProvider,
                                                              @NotNull List<String> keywords) {
-        Document document = resolveViewProvider.getDocument();
+        @Nullable Document document = resolveViewProvider.getDocument();
         if (document == null) {
             return null;
         }
-        PsiElement psiElement = Prev.prevCompactElement(lineInfo, resolve, document);
+        @Nullable PsiElement psiElement = Prev.prevCompactElement(lineInfo, resolve, document);
         if (!keywords.isEmpty()) {
             while (psiElement != null) {
                 String text = psiElement.getText();
@@ -69,7 +69,7 @@ public class ResolveDoc {
                 }
             }
         }
-        StringBuilder sb = new StringBuilder();
+        @NotNull StringBuilder sb = new StringBuilder();
         while (psiElement instanceof PsiComment) {
             String text = psiElement.getText();
             if (text != null) {
diff --git a/src/main/java/io/github/linwancen/plugin/show/settings/AbstractSettingsComponent.java b/src/main/java/io/github/linwancen/plugin/show/settings/AbstractSettingsComponent.java
index 4d613c9..b092fe6 100644
--- a/src/main/java/io/github/linwancen/plugin/show/settings/AbstractSettingsComponent.java
+++ b/src/main/java/io/github/linwancen/plugin/show/settings/AbstractSettingsComponent.java
@@ -38,7 +38,8 @@ public abstract class AbstractSettingsComponent {
         return lineEndFilter;
     }
 
-    protected FormBuilder add(FormBuilder formBuilder, JBCheckBox jbCheckBox, JBTextField jbTextField, String tip) {
+    protected FormBuilder add(@NotNull FormBuilder formBuilder, JBCheckBox jbCheckBox,
+                              @NotNull JBTextField jbTextField, @NotNull String tip) {
         return formBuilder.addLabeledComponent(JPanelFactory.of(jbCheckBox, new JBLabel(tip)), jbTextField, 1, true);
     }
 
diff --git a/src/main/java/io/github/linwancen/plugin/show/settings/AbstractSettingsConfigurable.java b/src/main/java/io/github/linwancen/plugin/show/settings/AbstractSettingsConfigurable.java
index 1a6c8f1..2fa7ac3 100644
--- a/src/main/java/io/github/linwancen/plugin/show/settings/AbstractSettingsConfigurable.java
+++ b/src/main/java/io/github/linwancen/plugin/show/settings/AbstractSettingsConfigurable.java
@@ -1,10 +1,13 @@
 package io.github.linwancen.plugin.show.settings;
 
+import org.jetbrains.annotations.NotNull;
+
 public class AbstractSettingsConfigurable {
 
     private AbstractSettingsConfigurable() {}
 
-    static boolean isModified(AbstractSettingsState settings, AbstractSettingsComponent component, boolean modified) {
+    static boolean isModified(@NotNull AbstractSettingsState settings, @NotNull AbstractSettingsComponent component,
+                              boolean modified) {
         modified |= !component.getLineInclude().equals(settings.getLineInclude());
         modified |= !component.getLineExclude().equals(settings.getLineExclude());
         modified |= !component.getDocInclude().equals(settings.getDocInclude());
@@ -14,7 +17,7 @@ public class AbstractSettingsConfigurable {
         return modified;
     }
 
-    static void apply(AbstractSettingsState settings, AbstractSettingsComponent component) {
+    static void apply(@NotNull AbstractSettingsState settings, @NotNull AbstractSettingsComponent component) {
         settings.setLineInclude(component.getLineInclude());
         settings.setLineExclude(component.getLineExclude());
         settings.setDocInclude(component.getDocInclude());
@@ -23,7 +26,7 @@ public class AbstractSettingsConfigurable {
         settings.setDocGet(component.getDocGet());
     }
 
-    static void reset(AbstractSettingsState settings, AbstractSettingsComponent component) {
+    static void reset(@NotNull AbstractSettingsState settings, @NotNull AbstractSettingsComponent component) {
         component.setLineInclude(settings.getLineInclude());
         component.setLineExclude(settings.getLineExclude());
         component.setDocInclude(settings.getDocInclude());
diff --git a/src/main/java/io/github/linwancen/plugin/show/settings/AbstractSettingsState.java b/src/main/java/io/github/linwancen/plugin/show/settings/AbstractSettingsState.java
index 12f713f..25c4650 100644
--- a/src/main/java/io/github/linwancen/plugin/show/settings/AbstractSettingsState.java
+++ b/src/main/java/io/github/linwancen/plugin/show/settings/AbstractSettingsState.java
@@ -1,21 +1,28 @@
 package io.github.linwancen.plugin.show.settings;
 
+import org.jetbrains.annotations.NotNull;
+
 import java.util.regex.Pattern;
 
 public abstract class AbstractSettingsState {
 
+    @NotNull
     public transient Pattern lineInclude = Pattern.compile("");
+    @NotNull
     public transient Pattern lineExclude = Pattern.compile("^java");
+    @NotNull
     public transient Pattern docInclude = Pattern.compile("");
+    @NotNull
     public transient Pattern docExclude = Pattern.compile("");
     public transient boolean docGetEffect = false;
+    @NotNull
     public transient Pattern docGet = Pattern.compile(".+?(?:[。\\r\\n]|\\. )");
 
     public String getLineInclude() {
         return lineInclude.pattern();
     }
 
-    public void setLineInclude(String lineInclude) {
+    public void setLineInclude(@NotNull String lineInclude) {
         this.lineInclude = Pattern.compile(lineInclude);
     }
 
@@ -23,7 +30,7 @@ public abstract class AbstractSettingsState {
         return lineExclude.pattern();
     }
 
-    public void setLineExclude(String lineExclude) {
+    public void setLineExclude(@NotNull String lineExclude) {
         this.lineExclude = Pattern.compile(lineExclude);
     }
 
@@ -32,7 +39,7 @@ public abstract class AbstractSettingsState {
         return docInclude.pattern();
     }
 
-    public void setDocInclude(String docInclude) {
+    public void setDocInclude(@NotNull String docInclude) {
         this.docInclude = Pattern.compile(docInclude);
     }
 
@@ -40,7 +47,7 @@ public abstract class AbstractSettingsState {
         return docExclude.pattern();
     }
 
-    public void setDocExclude(String docExclude) {
+    public void setDocExclude(@NotNull String docExclude) {
         this.docExclude = Pattern.compile(docExclude);
     }
 
@@ -49,7 +56,7 @@ public abstract class AbstractSettingsState {
         return docGet.pattern();
     }
 
-    public void setDocGet(String docExclude) {
+    public void setDocGet(@NotNull String docExclude) {
         this.docGet = Pattern.compile(docExclude);
     }
 }
diff --git a/src/main/java/io/github/linwancen/plugin/show/settings/AppSettingsComponent.java b/src/main/java/io/github/linwancen/plugin/show/settings/AppSettingsComponent.java
index 750ab68..811d8e0 100644
--- a/src/main/java/io/github/linwancen/plugin/show/settings/AppSettingsComponent.java
+++ b/src/main/java/io/github/linwancen/plugin/show/settings/AppSettingsComponent.java
@@ -7,6 +7,7 @@ import com.intellij.ui.components.JBLabel;
 import com.intellij.ui.components.JBTextField;
 import com.intellij.util.ui.FormBuilder;
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 
 import javax.swing.*;
 import java.awt.*;
@@ -69,15 +70,13 @@ public class AppSettingsComponent extends AbstractSettingsComponent {
 
     @NotNull
     protected JPanel lineEndFilterPanel() {
-        JPanel text = JPanelFactory.of(
+        @NotNull JPanel text = JPanelFactory.of(
                 new JBLabel("line count: "), lineEndCount,
                 new JBLabel("text color: "), lineEndColor,
                 new JBLabel("json text color: "), lineEndJsonColor,
                 new JBLabel("prefix: "), lineEndPrefix);
         FormBuilder formBuilder = FormBuilder.createFormBuilder()
-                // .addComponent(JPanelFactory.of(findElementRightToLeft))
                 .addSeparator()
-                // .addComponent(JPanelFactory.of(fromCall, fromNew, fromRef, inJson, skipAnnotation, skipAscii, skipBlank), 1)
                 .addComponent(JPanelFactory.of(fromNew, fromParam, getToSet, skipAnnotation, skipAscii, skipBlank), 1)
                 .addSeparator()
                 .addComponent(text)
@@ -89,6 +88,7 @@ public class AppSettingsComponent extends AbstractSettingsComponent {
         return myMainPanel;
     }
 
+    @NotNull
     public JComponent getPreferredFocusedComponent() {
         return showTreeComment;
     }
@@ -248,6 +248,7 @@ public class AppSettingsComponent extends AbstractSettingsComponent {
         skipBlank.setSelected(newStatus);
     }
 
+    @Nullable
     public Color getLineEndColor() {
         return lineEndColor.getSelectedColor();
     }
@@ -256,6 +257,7 @@ public class AppSettingsComponent extends AbstractSettingsComponent {
         lineEndColor.setSelectedColor(color);
     }
 
+    @Nullable
     public Color getLineEndJsonColor() {
         return lineEndJsonColor.getSelectedColor();
     }
diff --git a/src/main/java/io/github/linwancen/plugin/show/settings/AppSettingsConfigurable.java b/src/main/java/io/github/linwancen/plugin/show/settings/AppSettingsConfigurable.java
index 83039f4..2e33452 100644
--- a/src/main/java/io/github/linwancen/plugin/show/settings/AppSettingsConfigurable.java
+++ b/src/main/java/io/github/linwancen/plugin/show/settings/AppSettingsConfigurable.java
@@ -2,19 +2,24 @@ package io.github.linwancen.plugin.show.settings;
 
 import com.google.common.base.Splitter;
 import com.intellij.openapi.options.Configurable;
+import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
 import javax.swing.*;
 
 public class AppSettingsConfigurable implements Configurable {
 
+    @SuppressWarnings("NotNullFieldNotInitialized")
+    @NotNull
     private AppSettingsComponent mySettingsComponent;
 
+    @NotNull
     @Override
     public String getDisplayName() {
         return "Show Comment Global.";
     }
 
+    @NotNull
     @Override
     public JComponent getPreferredFocusedComponent() {
         return mySettingsComponent.getPreferredFocusedComponent();
@@ -29,7 +34,7 @@ public class AppSettingsConfigurable implements Configurable {
 
     @Override
     public boolean isModified() {
-        AppSettingsState settings = AppSettingsState.getInstance();
+        @NotNull AppSettingsState settings = AppSettingsState.getInstance();
         boolean modified = mySettingsComponent.getShowTreeComment() != settings.showTreeComment;
         modified |= mySettingsComponent.getCompact() != settings.compact;
 
@@ -47,8 +52,8 @@ public class AppSettingsConfigurable implements Configurable {
         modified |= !mySettingsComponent.getLineTags().equals(String.join("|", settings.lineTags));
 
         modified |= !mySettingsComponent.getLineEndCount().equals(String.valueOf(settings.lineEndCount));
-        modified |= !mySettingsComponent.getLineEndColor().equals(settings.lineEndTextAttr.getForegroundColor());
-        modified |= !mySettingsComponent.getLineEndJsonColor().equals(settings.lineEndJsonTextAttr.getForegroundColor());
+        modified |= !settings.lineEndTextAttr.getForegroundColor().equals(mySettingsComponent.getLineEndColor());
+        modified |= !settings.lineEndJsonTextAttr.getForegroundColor().equals(mySettingsComponent.getLineEndJsonColor());
         modified |= !mySettingsComponent.getLineEndPrefix().equals(settings.lineEndPrefix);
 
         modified |= mySettingsComponent.getGetToSet() != settings.getToSet;
@@ -65,7 +70,7 @@ public class AppSettingsConfigurable implements Configurable {
 
     @Override
     public void apply() {
-        AppSettingsState settings = AppSettingsState.getInstance();
+        @NotNull AppSettingsState settings = AppSettingsState.getInstance();
         settings.showTreeComment = mySettingsComponent.getShowTreeComment();
         settings.compact = mySettingsComponent.getCompact();
 
@@ -103,7 +108,7 @@ public class AppSettingsConfigurable implements Configurable {
 
     @Override
     public void reset() {
-        AppSettingsState settings = AppSettingsState.getInstance();
+        @NotNull AppSettingsState settings = AppSettingsState.getInstance();
         mySettingsComponent.setShowTreeComment(settings.showTreeComment);
         mySettingsComponent.setCompact(settings.compact);
 
@@ -137,6 +142,7 @@ public class AppSettingsConfigurable implements Configurable {
 
     @Override
     public void disposeUIResources() {
+        //noinspection ConstantConditions
         mySettingsComponent = null;
     }
 
diff --git a/src/main/java/io/github/linwancen/plugin/show/settings/AppSettingsState.java b/src/main/java/io/github/linwancen/plugin/show/settings/AppSettingsState.java
index 8aa08ed..309a70f 100644
--- a/src/main/java/io/github/linwancen/plugin/show/settings/AppSettingsState.java
+++ b/src/main/java/io/github/linwancen/plugin/show/settings/AppSettingsState.java
@@ -34,7 +34,9 @@ public class AppSettingsState extends AbstractSettingsState implements Persisten
     public boolean showLineEndCommentGo = true;
     public boolean showLineEndCommentKotlin = true;
 
+    @NotNull
     public String[] treeTags = {"author"};
+    @NotNull
     public String[] lineTags = {};
 
     public final TextAttributes lineEndTextAttr = new TextAttributes(
@@ -43,6 +45,7 @@ public class AppSettingsState extends AbstractSettingsState implements Persisten
     public final TextAttributes lineEndJsonTextAttr = new TextAttributes(new JBColor(Gray._140, Gray._140),
             null, null, null, Font.ITALIC);
 
+    @NotNull
     public String lineEndPrefix = "   // ";
     public int lineEndCount = 2;
     public int lineEndLen = 0;
@@ -53,6 +56,7 @@ public class AppSettingsState extends AbstractSettingsState implements Persisten
     public boolean skipAscii = !"en".equals(Locale.getDefault().getLanguage());
     public boolean skipBlank = true;
 
+    @NotNull
     public static AppSettingsState getInstance() {
         AppSettingsState service = ApplicationManager.getApplication().getService(AppSettingsState.class);
         if (service == null) {
@@ -72,20 +76,22 @@ public class AppSettingsState extends AbstractSettingsState implements Persisten
         XmlSerializerUtil.copyBean(state, this);
     }
 
+    @NotNull
     public String getLineEndColor() {
         return Integer.toHexString(lineEndTextAttr.getForegroundColor().getRGB()).toUpperCase();
     }
 
-    public void setLineEndColor(String s) {
+    public void setLineEndColor(@NotNull String s) {
         int rgb = new BigInteger(s, 16).intValue();
         lineEndTextAttr.setForegroundColor(new JBColor(new Color(rgb), new Color(rgb)));
     }
 
+    @NotNull
     public String getLineEndJsonColor() {
         return Integer.toHexString(lineEndJsonTextAttr.getForegroundColor().getRGB()).toUpperCase();
     }
 
-    public void setLineEndJsonColor(String s) {
+    public void setLineEndJsonColor(@NotNull String s) {
         int rgb = new BigInteger(s, 16).intValue();
         lineEndJsonTextAttr.setForegroundColor(new JBColor(new Color(rgb), new Color(rgb)));
     }
diff --git a/src/main/java/io/github/linwancen/plugin/show/settings/JPanelFactory.java b/src/main/java/io/github/linwancen/plugin/show/settings/JPanelFactory.java
index 026e9ad..18b794c 100644
--- a/src/main/java/io/github/linwancen/plugin/show/settings/JPanelFactory.java
+++ b/src/main/java/io/github/linwancen/plugin/show/settings/JPanelFactory.java
@@ -1,5 +1,8 @@
 package io.github.linwancen.plugin.show.settings;
 
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
 import javax.swing.*;
 import java.awt.*;
 
@@ -7,9 +10,10 @@ public class JPanelFactory {
 
     private JPanelFactory() {}
 
-    public static JPanel of(Component... components) {
-        JPanel jPanel = new JPanel(new FlowLayout(FlowLayout.LEFT));
-        for (Component component : components) {
+    @NotNull
+    public static JPanel of(@NotNull Component... components) {
+        @NotNull JPanel jPanel = new JPanel(new FlowLayout(FlowLayout.LEFT));
+        for (@Nullable Component component : components) {
             if (component != null) {
                 jPanel.add(component);
             }
diff --git a/src/main/java/io/github/linwancen/plugin/show/settings/ProjectSettingsComponent.java b/src/main/java/io/github/linwancen/plugin/show/settings/ProjectSettingsComponent.java
index 76be6b1..4e6b626 100644
--- a/src/main/java/io/github/linwancen/plugin/show/settings/ProjectSettingsComponent.java
+++ b/src/main/java/io/github/linwancen/plugin/show/settings/ProjectSettingsComponent.java
@@ -32,6 +32,7 @@ public class ProjectSettingsComponent extends AbstractSettingsComponent {
         return myMainPanel;
     }
 
+    @NotNull
     public JComponent getPreferredFocusedComponent() {
         return projectFilterEffective;
     }
diff --git a/src/main/java/io/github/linwancen/plugin/show/settings/ProjectSettingsConfigurable.java b/src/main/java/io/github/linwancen/plugin/show/settings/ProjectSettingsConfigurable.java
index 64bba5a..8e8e6e0 100644
--- a/src/main/java/io/github/linwancen/plugin/show/settings/ProjectSettingsConfigurable.java
+++ b/src/main/java/io/github/linwancen/plugin/show/settings/ProjectSettingsConfigurable.java
@@ -16,17 +16,21 @@ public class ProjectSettingsConfigurable extends ModuleAwareProjectConfigurable<
 
     @NotNull
     @Override
-    protected ProjectSettingsConfigurable createModuleConfigurable(Module module) {
+    protected ProjectSettingsConfigurable createModuleConfigurable(@NotNull Module module) {
         return new ProjectSettingsConfigurable(module.getProject());
     }
 
+    @SuppressWarnings("NotNullFieldNotInitialized")
+    @NotNull
     private ProjectSettingsComponent mySettingsComponent;
 
+    @NotNull
     @Override
     public String getDisplayName() {
         return "Show Comment Project.";
     }
 
+    @NotNull
     @Override
     public JComponent getPreferredFocusedComponent() {
         return mySettingsComponent.getPreferredFocusedComponent();
@@ -41,7 +45,7 @@ public class ProjectSettingsConfigurable extends ModuleAwareProjectConfigurable<
 
     @Override
     public boolean isModified() {
-        ProjectSettingsState settings = ProjectSettingsState.getInstance(getProject());
+        @NotNull ProjectSettingsState settings = ProjectSettingsState.getInstance(getProject());
         boolean modified = mySettingsComponent.getGlobalFilterEffective() != settings.globalFilterEffective;
         modified |= mySettingsComponent.getProjectFilterEffective() != settings.projectFilterEffective;
         modified = AbstractSettingsConfigurable.isModified(settings, mySettingsComponent, modified);
@@ -50,7 +54,7 @@ public class ProjectSettingsConfigurable extends ModuleAwareProjectConfigurable<
 
     @Override
     public void apply() {
-        ProjectSettingsState settings = ProjectSettingsState.getInstance(getProject());
+        @NotNull ProjectSettingsState settings = ProjectSettingsState.getInstance(getProject());
         settings.globalFilterEffective = mySettingsComponent.getGlobalFilterEffective();
         settings.projectFilterEffective = mySettingsComponent.getProjectFilterEffective();
         AbstractSettingsConfigurable.apply(settings, mySettingsComponent);
@@ -58,7 +62,7 @@ public class ProjectSettingsConfigurable extends ModuleAwareProjectConfigurable<
 
     @Override
     public void reset() {
-        ProjectSettingsState settings = ProjectSettingsState.getInstance(getProject());
+        @NotNull ProjectSettingsState settings = ProjectSettingsState.getInstance(getProject());
         mySettingsComponent.setGlobalFilterEffective(settings.globalFilterEffective);
         mySettingsComponent.setProjectFilterEffective(settings.projectFilterEffective);
         AbstractSettingsConfigurable.reset(settings, mySettingsComponent);
@@ -66,6 +70,7 @@ public class ProjectSettingsConfigurable extends ModuleAwareProjectConfigurable<
 
     @Override
     public void disposeUIResources() {
+        //noinspection ConstantConditions
         mySettingsComponent = null;
     }
 
diff --git a/src/main/java/io/github/linwancen/plugin/show/settings/ProjectSettingsState.java b/src/main/java/io/github/linwancen/plugin/show/settings/ProjectSettingsState.java
index aacc772..7386f69 100644
--- a/src/main/java/io/github/linwancen/plugin/show/settings/ProjectSettingsState.java
+++ b/src/main/java/io/github/linwancen/plugin/show/settings/ProjectSettingsState.java
@@ -12,11 +12,12 @@ import org.jetbrains.annotations.Nullable;
         name = "io.github.linwancen.plugin.show.settings.ProjectSettingsState",
         storages = @Storage("ShowCommentProject.xml")
 )
-public class ProjectSettingsState extends AbstractSettingsState  implements PersistentStateComponent<ProjectSettingsState> {
+public class ProjectSettingsState extends AbstractSettingsState implements PersistentStateComponent<ProjectSettingsState> {
 
     public boolean globalFilterEffective = true;
     public boolean projectFilterEffective = false;
 
+    @NotNull
     public static ProjectSettingsState getInstance(@NotNull Project project) {
         ProjectSettingsState service = project.getService(ProjectSettingsState.class);
         if (service == null) {
diff --git a/src/main/resources/META-INF/plugin.xml b/src/main/resources/META-INF/plugin.xml
index 4dc832a..a7c6d90 100644
--- a/src/main/resources/META-INF/plugin.xml
+++ b/src/main/resources/META-INF/plugin.xml
@@ -1,9 +1,9 @@
 <idea-plugin url="https://plugins.jetbrains.com/plugin/18553-show-comment">
-    <id>io.github.linwancen.show-comment</id>
-    <name>Show Comment</name>
-    <vendor email="1498425439@qq.com" url="https://github.com/LinWanCen/show-comment">林万程</vendor>
+  <id>io.github.linwancen.show-comment</id>
+  <name>Show Comment</name>
+  <vendor email="1498425439@qq.com" url="https://github.com/LinWanCen/show-comment">林万程</vendor>
 
-    <description><![CDATA[
+  <description><![CDATA[
 Show doc comment at the Project view Tree, line End, json etc.
 <ul>
 <li>"xx-ClassNameOrSimpleName.json" and jump to field
@@ -53,79 +53,79 @@ Show doc comment at the Project view Tree, line End, json etc.
 主页一个 Start，您的支持是项目前进的动力。
     ]]></description>
 
-    <!-- please see https://plugins.jetbrains.com/docs/intellij/plugin-compatibility.html
-         on how to target different products -->
-    <depends optional="true" config-file="java.xml">com.intellij.modules.java</depends>
-    <depends optional="true" config-file="sql.xml">com.intellij.database</depends>
-    <depends optional="true" config-file="js.xml">JavaScript</depends>
-    <depends optional="true" config-file="python.xml">com.intellij.modules.python</depends>
-    <depends optional="true" config-file="go.xml">org.jetbrains.plugins.go</depends>
-    <depends optional="true" config-file="kotlin.xml">org.jetbrains.kotlin</depends>
-    <!--suppress PluginXmlValidity, MybatisMapperXmlInspection -->
-    <!--<depends optional="true" config-file="cs.xml">com.intellij.modules.rider</depends>-->
+  <!-- please see https://plugins.jetbrains.com/docs/intellij/plugin-compatibility.html
+       on how to target different products -->
+  <depends optional="true" config-file="java.xml">com.intellij.modules.java</depends>
+  <depends optional="true" config-file="sql.xml">com.intellij.database</depends>
+  <depends optional="true" config-file="js.xml">JavaScript</depends>
+  <depends optional="true" config-file="python.xml">com.intellij.modules.python</depends>
+  <depends optional="true" config-file="go.xml">org.jetbrains.plugins.go</depends>
+  <depends optional="true" config-file="kotlin.xml">org.jetbrains.kotlin</depends>
+  <!--suppress PluginXmlValidity, MybatisMapperXmlInspection -->
+  <!--<depends optional="true" config-file="cs.xml">com.intellij.modules.rider</depends>-->
 
-    <applicationListeners>
-        <listener class="io.github.linwancen.plugin.show.ext.conf.ConfFileListener"
-                  topic="com.intellij.openapi.vfs.newvfs.BulkFileListener"/>
-        <listener class="io.github.linwancen.plugin.show.ext.conf.ConfFileChangeListener"
-                  topic="com.intellij.openapi.fileEditor.FileEditorManagerListener"/>
-    </applicationListeners>
+  <applicationListeners>
+    <listener class="io.github.linwancen.plugin.show.ext.conf.ConfFileListener"
+              topic="com.intellij.openapi.vfs.newvfs.BulkFileListener"/>
+    <listener class="io.github.linwancen.plugin.show.ext.conf.ConfFileChangeListener"
+              topic="com.intellij.openapi.fileEditor.FileEditorManagerListener"/>
+  </applicationListeners>
 
-    <projectListeners>
-        <listener class="io.github.linwancen.plugin.show.ext.conf.ConfFileInitListener"
-                  topic="com.intellij.openapi.project.ProjectManagerListener"/>
-    </projectListeners>
+  <projectListeners>
+    <listener class="io.github.linwancen.plugin.show.ext.conf.ConfFileInitListener"
+              topic="com.intellij.openapi.project.ProjectManagerListener"/>
+  </projectListeners>
 
-    <extensions defaultExtensionNs="com.intellij">
-        <editor.linePainter implementation="io.github.linwancen.plugin.show.LineEnd"/>
-        <projectViewNodeDecorator implementation="io.github.linwancen.plugin.show.Tree"/>
-        <defaultLiveTemplates file="/liveTemplates/show-comment-doc.xml"/>
-        <defaultLiveTemplates file="/liveTemplates/show-comment-xml.xml"/>
+  <extensions defaultExtensionNs="com.intellij">
+    <editor.linePainter implementation="io.github.linwancen.plugin.show.LineEnd"/>
+    <projectViewNodeDecorator implementation="io.github.linwancen.plugin.show.Tree"/>
+    <defaultLiveTemplates file="/liveTemplates/show-comment-doc.xml"/>
+    <defaultLiveTemplates file="/liveTemplates/show-comment-xml.xml"/>
 
-        <applicationConfigurable parentId="tools"
-                                 instance="io.github.linwancen.plugin.show.settings.AppSettingsConfigurable"
-                                 id="io.github.linwancen.plugin.show.settings.AppSettingsConfigurable"
-                                 displayName="// Show Comment Global"/>
-        <applicationService serviceImplementation="io.github.linwancen.plugin.show.settings.AppSettingsState"/>
-        <projectConfigurable parentId="tools"
-                             instance="io.github.linwancen.plugin.show.settings.ProjectSettingsConfigurable"
-                             id="io.github.linwancen.plugin.show.settings.ProjectSettingsConfigurable"
-                             displayName="// Show Comment Project"/>
-        <projectService serviceImplementation="io.github.linwancen.plugin.show.settings.ProjectSettingsState"/>
-    </extensions>
+    <applicationConfigurable parentId="tools"
+                             instance="io.github.linwancen.plugin.show.settings.AppSettingsConfigurable"
+                             id="io.github.linwancen.plugin.show.settings.AppSettingsConfigurable"
+                             displayName="// Show Comment Global"/>
+    <applicationService serviceImplementation="io.github.linwancen.plugin.show.settings.AppSettingsState"/>
+    <projectConfigurable parentId="tools"
+                         instance="io.github.linwancen.plugin.show.settings.ProjectSettingsConfigurable"
+                         id="io.github.linwancen.plugin.show.settings.ProjectSettingsConfigurable"
+                         displayName="// Show Comment Project"/>
+    <projectService serviceImplementation="io.github.linwancen.plugin.show.settings.ProjectSettingsState"/>
+  </extensions>
 
-    <actions>
-        <action
-            id="io.github.linwancen.plugin.show.ext.conf.ReLoadExtDocAction"
-            class="io.github.linwancen.plugin.show.ext.conf.ReloadExtDocAction"
-            text="🔄 // Reload External Comment">
-            <add-to-group group-id="ToolsMenu"/>
-        </action>
-        <action
-            id="io.github.linwancen.plugin.show.ext.conf.ResetExtDocAction"
-            class="io.github.linwancen.plugin.show.ext.conf.ResetExtDocAction"
-            text="🆑 // Clear External Comment">
-            <add-to-group group-id="ToolsMenu"/>
-        </action>
-        <action
-            id="io.github.linwancen.plugin.show.LineEndCopy"
-            class="io.github.linwancen.plugin.show.LineEndCopy"
-            text="// Copy With Line Comment">
-            <add-to-group group-id="EditorPopupMenu" anchor="after"
-                          relative-to-action="CopyReference"/>
-        </action>
-        <action
-            id="io.github.linwancen.plugin.show.CopyReferenceSimple"
-            class="io.github.linwancen.plugin.show.CopyReferenceSimple"
-            text="Copy Class.Method/File:Line">
-            <add-to-group group-id="EditorPopupMenu" anchor="after"
-                          relative-to-action="CopyReference"/>
-        </action>
-        <action
-            id="io.github.linwancen.plugin.show.LineEndAdd"
-            class="io.github.linwancen.plugin.show.LineEndAdd"
-            text="// Add Line Comment">
-            <add-to-group group-id="ProjectViewPopupMenu" anchor="last"/>
-        </action>
-    </actions>
+  <actions>
+    <action
+        id="io.github.linwancen.plugin.show.ext.conf.ReLoadExtDocAction"
+        class="io.github.linwancen.plugin.show.ext.conf.ReloadExtDocAction"
+        text="🔄 // Reload External Comment">
+      <add-to-group group-id="ToolsMenu"/>
+    </action>
+    <action
+        id="io.github.linwancen.plugin.show.ext.conf.ResetExtDocAction"
+        class="io.github.linwancen.plugin.show.ext.conf.ResetExtDocAction"
+        text="🆑 // Clear External Comment">
+      <add-to-group group-id="ToolsMenu"/>
+    </action>
+    <action
+        id="io.github.linwancen.plugin.show.LineEndCopy"
+        class="io.github.linwancen.plugin.show.LineEndCopy"
+        text="// Copy With Line Comment">
+      <add-to-group group-id="EditorPopupMenu" anchor="after"
+                    relative-to-action="CopyReference"/>
+    </action>
+    <action
+        id="io.github.linwancen.plugin.show.CopyReferenceSimple"
+        class="io.github.linwancen.plugin.show.CopyReferenceSimple"
+        text="Copy Class.Method/File:Line">
+      <add-to-group group-id="EditorPopupMenu" anchor="after"
+                    relative-to-action="CopyReference"/>
+    </action>
+    <action
+        id="io.github.linwancen.plugin.show.LineEndAdd"
+        class="io.github.linwancen.plugin.show.LineEndAdd"
+        text="// Add Line Comment">
+      <add-to-group group-id="ProjectViewPopupMenu" anchor="last"/>
+    </action>
+  </actions>
 </idea-plugin>
\ No newline at end of file
diff --git a/src/main/resources/liveTemplates/show-comment-doc.xml b/src/main/resources/liveTemplates/show-comment-doc.xml
index ad25ff4..45267ee 100644
--- a/src/main/resources/liveTemplates/show-comment-doc.xml
+++ b/src/main/resources/liveTemplates/show-comment-doc.xml
@@ -1,254 +1,263 @@
 <templateSet group="show-comment-doc">
-  <template name="doc" value="/** $SELECTION$ */" description="/** one line */" toReformat="false" toShortenFQNames="true">
+  <template name="doc" value="/** $SELECTION$ */" description="/** one line */" toReformat="false"
+            toShortenFQNames="true">
     <context>
-      <option name="COMPLETION" value="false" />
-      <option name="ECMAScript6" value="true" />
-      <option name="ES6_CLASS" value="false" />
-      <option name="ES6_EXPRESSION" value="false" />
-      <option name="ES6_STATEMENT" value="false" />
-      <option name="GROOVY" value="true" />
-      <option name="GROOVY_EXPRESSION" value="false" />
-      <option name="GROOVY_STATEMENT" value="false" />
-      <option name="JAVA_CODE" value="true" />
-      <option name="JAVA_COMMENT" value="false" />
-      <option name="JAVA_CONSUMER" value="false" />
-      <option name="JAVA_ELSE_PLACE" value="false" />
-      <option name="JAVA_EXPRESSION" value="false" />
-      <option name="JAVA_SCRIPT" value="true" />
-      <option name="JAVA_STATEMENT" value="false" />
-      <option name="JAVA_STRING" value="false" />
-      <option name="JSX_HTML" value="false" />
-      <option name="JS_CLASS" value="false" />
-      <option name="JS_DOT_PROPERTY_ACCESS" value="false" />
-      <option name="JS_EXPRESSION" value="false" />
-      <option name="JS_STATEMENT" value="false" />
-      <option name="KOTLIN" value="true" />
-      <option name="KOTLIN_CLASS" value="false" />
-      <option name="KOTLIN_COMMENT" value="false" />
-      <option name="KOTLIN_EXPRESSION" value="false" />
-      <option name="KOTLIN_STATEMENT" value="false" />
-      <option name="TS_CLASS" value="false" />
-      <option name="TS_EXPRESSION" value="false" />
-      <option name="TS_STATEMENT" value="false" />
-      <option name="TypeScript" value="true" />
+      <option name="COMPLETION" value="false"/>
+      <option name="ECMAScript6" value="true"/>
+      <option name="ES6_CLASS" value="false"/>
+      <option name="ES6_EXPRESSION" value="false"/>
+      <option name="ES6_STATEMENT" value="false"/>
+      <option name="GROOVY" value="true"/>
+      <option name="GROOVY_EXPRESSION" value="false"/>
+      <option name="GROOVY_STATEMENT" value="false"/>
+      <option name="JAVA_CODE" value="true"/>
+      <option name="JAVA_COMMENT" value="false"/>
+      <option name="JAVA_CONSUMER" value="false"/>
+      <option name="JAVA_ELSE_PLACE" value="false"/>
+      <option name="JAVA_EXPRESSION" value="false"/>
+      <option name="JAVA_SCRIPT" value="true"/>
+      <option name="JAVA_STATEMENT" value="false"/>
+      <option name="JAVA_STRING" value="false"/>
+      <option name="JSX_HTML" value="false"/>
+      <option name="JS_CLASS" value="false"/>
+      <option name="JS_DOT_PROPERTY_ACCESS" value="false"/>
+      <option name="JS_EXPRESSION" value="false"/>
+      <option name="JS_STATEMENT" value="false"/>
+      <option name="KOTLIN" value="true"/>
+      <option name="KOTLIN_CLASS" value="false"/>
+      <option name="KOTLIN_COMMENT" value="false"/>
+      <option name="KOTLIN_EXPRESSION" value="false"/>
+      <option name="KOTLIN_STATEMENT" value="false"/>
+      <option name="TS_CLASS" value="false"/>
+      <option name="TS_EXPRESSION" value="false"/>
+      <option name="TS_STATEMENT" value="false"/>
+      <option name="TypeScript" value="true"/>
     </context>
   </template>
-  <template name="docc" value="/**&#10; * $SELECTION$&#10; */" description="/** multi line */" toReformat="false" toShortenFQNames="true">
+  <template name="docc" value="/**&#10; * $SELECTION$&#10; */" description="/** multi line */" toReformat="false"
+            toShortenFQNames="true">
     <context>
-      <option name="COMPLETION" value="false" />
-      <option name="ECMAScript6" value="true" />
-      <option name="ES6_CLASS" value="false" />
-      <option name="ES6_EXPRESSION" value="false" />
-      <option name="ES6_STATEMENT" value="false" />
-      <option name="GROOVY" value="true" />
-      <option name="GROOVY_EXPRESSION" value="false" />
-      <option name="GROOVY_STATEMENT" value="false" />
-      <option name="JAVA_CODE" value="true" />
-      <option name="JAVA_COMMENT" value="false" />
-      <option name="JAVA_CONSUMER" value="false" />
-      <option name="JAVA_ELSE_PLACE" value="false" />
-      <option name="JAVA_EXPRESSION" value="false" />
-      <option name="JAVA_SCRIPT" value="true" />
-      <option name="JAVA_STATEMENT" value="false" />
-      <option name="JAVA_STRING" value="false" />
-      <option name="JSX_HTML" value="false" />
-      <option name="JS_CLASS" value="false" />
-      <option name="JS_DOT_PROPERTY_ACCESS" value="false" />
-      <option name="JS_EXPRESSION" value="false" />
-      <option name="JS_STATEMENT" value="false" />
-      <option name="KOTLIN" value="true" />
-      <option name="KOTLIN_CLASS" value="false" />
-      <option name="KOTLIN_COMMENT" value="false" />
-      <option name="KOTLIN_EXPRESSION" value="false" />
-      <option name="KOTLIN_STATEMENT" value="false" />
-      <option name="TS_CLASS" value="false" />
-      <option name="TS_EXPRESSION" value="false" />
-      <option name="TS_STATEMENT" value="false" />
-      <option name="TypeScript" value="true" />
+      <option name="COMPLETION" value="false"/>
+      <option name="ECMAScript6" value="true"/>
+      <option name="ES6_CLASS" value="false"/>
+      <option name="ES6_EXPRESSION" value="false"/>
+      <option name="ES6_STATEMENT" value="false"/>
+      <option name="GROOVY" value="true"/>
+      <option name="GROOVY_EXPRESSION" value="false"/>
+      <option name="GROOVY_STATEMENT" value="false"/>
+      <option name="JAVA_CODE" value="true"/>
+      <option name="JAVA_COMMENT" value="false"/>
+      <option name="JAVA_CONSUMER" value="false"/>
+      <option name="JAVA_ELSE_PLACE" value="false"/>
+      <option name="JAVA_EXPRESSION" value="false"/>
+      <option name="JAVA_SCRIPT" value="true"/>
+      <option name="JAVA_STATEMENT" value="false"/>
+      <option name="JAVA_STRING" value="false"/>
+      <option name="JSX_HTML" value="false"/>
+      <option name="JS_CLASS" value="false"/>
+      <option name="JS_DOT_PROPERTY_ACCESS" value="false"/>
+      <option name="JS_EXPRESSION" value="false"/>
+      <option name="JS_STATEMENT" value="false"/>
+      <option name="KOTLIN" value="true"/>
+      <option name="KOTLIN_CLASS" value="false"/>
+      <option name="KOTLIN_COMMENT" value="false"/>
+      <option name="KOTLIN_EXPRESSION" value="false"/>
+      <option name="KOTLIN_STATEMENT" value="false"/>
+      <option name="TS_CLASS" value="false"/>
+      <option name="TS_EXPRESSION" value="false"/>
+      <option name="TS_STATEMENT" value="false"/>
+      <option name="TypeScript" value="true"/>
     </context>
   </template>
-  <template name="docb" value="/**&#10; * $SELECTION$&#10; * &lt;br&gt;&#10; */" description="/** &lt;br&gt; */" toReformat="false" toShortenFQNames="true">
+  <template name="docb" value="/**&#10; * $SELECTION$&#10; * &lt;br&gt;&#10; */" description="/** &lt;br&gt; */"
+            toReformat="false" toShortenFQNames="true">
     <context>
-      <option name="COMPLETION" value="false" />
-      <option name="ECMAScript6" value="true" />
-      <option name="ES6_CLASS" value="false" />
-      <option name="ES6_EXPRESSION" value="false" />
-      <option name="ES6_STATEMENT" value="false" />
-      <option name="GROOVY" value="true" />
-      <option name="GROOVY_EXPRESSION" value="false" />
-      <option name="GROOVY_STATEMENT" value="false" />
-      <option name="JAVA_CODE" value="true" />
-      <option name="JAVA_COMMENT" value="false" />
-      <option name="JAVA_CONSUMER" value="false" />
-      <option name="JAVA_ELSE_PLACE" value="false" />
-      <option name="JAVA_EXPRESSION" value="false" />
-      <option name="JAVA_SCRIPT" value="true" />
-      <option name="JAVA_STATEMENT" value="false" />
-      <option name="JAVA_STRING" value="false" />
-      <option name="JSX_HTML" value="false" />
-      <option name="JS_CLASS" value="false" />
-      <option name="JS_DOT_PROPERTY_ACCESS" value="false" />
-      <option name="JS_EXPRESSION" value="false" />
-      <option name="JS_STATEMENT" value="false" />
-      <option name="KOTLIN" value="true" />
-      <option name="KOTLIN_CLASS" value="false" />
-      <option name="KOTLIN_COMMENT" value="false" />
-      <option name="KOTLIN_EXPRESSION" value="false" />
-      <option name="KOTLIN_STATEMENT" value="false" />
-      <option name="TS_CLASS" value="false" />
-      <option name="TS_EXPRESSION" value="false" />
-      <option name="TS_STATEMENT" value="false" />
-      <option name="TypeScript" value="true" />
+      <option name="COMPLETION" value="false"/>
+      <option name="ECMAScript6" value="true"/>
+      <option name="ES6_CLASS" value="false"/>
+      <option name="ES6_EXPRESSION" value="false"/>
+      <option name="ES6_STATEMENT" value="false"/>
+      <option name="GROOVY" value="true"/>
+      <option name="GROOVY_EXPRESSION" value="false"/>
+      <option name="GROOVY_STATEMENT" value="false"/>
+      <option name="JAVA_CODE" value="true"/>
+      <option name="JAVA_COMMENT" value="false"/>
+      <option name="JAVA_CONSUMER" value="false"/>
+      <option name="JAVA_ELSE_PLACE" value="false"/>
+      <option name="JAVA_EXPRESSION" value="false"/>
+      <option name="JAVA_SCRIPT" value="true"/>
+      <option name="JAVA_STATEMENT" value="false"/>
+      <option name="JAVA_STRING" value="false"/>
+      <option name="JSX_HTML" value="false"/>
+      <option name="JS_CLASS" value="false"/>
+      <option name="JS_DOT_PROPERTY_ACCESS" value="false"/>
+      <option name="JS_EXPRESSION" value="false"/>
+      <option name="JS_STATEMENT" value="false"/>
+      <option name="KOTLIN" value="true"/>
+      <option name="KOTLIN_CLASS" value="false"/>
+      <option name="KOTLIN_COMMENT" value="false"/>
+      <option name="KOTLIN_EXPRESSION" value="false"/>
+      <option name="KOTLIN_STATEMENT" value="false"/>
+      <option name="TS_CLASS" value="false"/>
+      <option name="TS_EXPRESSION" value="false"/>
+      <option name="TS_STATEMENT" value="false"/>
+      <option name="TypeScript" value="true"/>
     </context>
   </template>
-  <template name="docl" value="/**&#10; * $SELECTION$&#10; * &lt;ul&gt;&#10; * &lt;li&gt;&#10; * &lt;/ul&gt;&#10; */" description="/** &lt;li&gt; */" toReformat="false" toShortenFQNames="true">
+  <template name="docl" value="/**&#10; * $SELECTION$&#10; * &lt;ul&gt;&#10; * &lt;li&gt;&#10; * &lt;/ul&gt;&#10; */"
+            description="/** &lt;li&gt; */" toReformat="false" toShortenFQNames="true">
     <context>
-      <option name="COMPLETION" value="false" />
-      <option name="ECMAScript6" value="true" />
-      <option name="ES6_CLASS" value="false" />
-      <option name="ES6_EXPRESSION" value="false" />
-      <option name="ES6_STATEMENT" value="false" />
-      <option name="GROOVY" value="true" />
-      <option name="GROOVY_EXPRESSION" value="false" />
-      <option name="GROOVY_STATEMENT" value="false" />
-      <option name="JAVA_CODE" value="true" />
-      <option name="JAVA_COMMENT" value="false" />
-      <option name="JAVA_CONSUMER" value="false" />
-      <option name="JAVA_ELSE_PLACE" value="false" />
-      <option name="JAVA_EXPRESSION" value="false" />
-      <option name="JAVA_SCRIPT" value="true" />
-      <option name="JAVA_STATEMENT" value="false" />
-      <option name="JAVA_STRING" value="false" />
-      <option name="JSX_HTML" value="false" />
-      <option name="JS_CLASS" value="false" />
-      <option name="JS_DOT_PROPERTY_ACCESS" value="false" />
-      <option name="JS_EXPRESSION" value="false" />
-      <option name="JS_STATEMENT" value="false" />
-      <option name="KOTLIN" value="true" />
-      <option name="KOTLIN_CLASS" value="false" />
-      <option name="KOTLIN_COMMENT" value="false" />
-      <option name="KOTLIN_EXPRESSION" value="false" />
-      <option name="KOTLIN_STATEMENT" value="false" />
-      <option name="TS_CLASS" value="false" />
-      <option name="TS_EXPRESSION" value="false" />
-      <option name="TS_STATEMENT" value="false" />
-      <option name="TypeScript" value="true" />
+      <option name="COMPLETION" value="false"/>
+      <option name="ECMAScript6" value="true"/>
+      <option name="ES6_CLASS" value="false"/>
+      <option name="ES6_EXPRESSION" value="false"/>
+      <option name="ES6_STATEMENT" value="false"/>
+      <option name="GROOVY" value="true"/>
+      <option name="GROOVY_EXPRESSION" value="false"/>
+      <option name="GROOVY_STATEMENT" value="false"/>
+      <option name="JAVA_CODE" value="true"/>
+      <option name="JAVA_COMMENT" value="false"/>
+      <option name="JAVA_CONSUMER" value="false"/>
+      <option name="JAVA_ELSE_PLACE" value="false"/>
+      <option name="JAVA_EXPRESSION" value="false"/>
+      <option name="JAVA_SCRIPT" value="true"/>
+      <option name="JAVA_STATEMENT" value="false"/>
+      <option name="JAVA_STRING" value="false"/>
+      <option name="JSX_HTML" value="false"/>
+      <option name="JS_CLASS" value="false"/>
+      <option name="JS_DOT_PROPERTY_ACCESS" value="false"/>
+      <option name="JS_EXPRESSION" value="false"/>
+      <option name="JS_STATEMENT" value="false"/>
+      <option name="KOTLIN" value="true"/>
+      <option name="KOTLIN_CLASS" value="false"/>
+      <option name="KOTLIN_COMMENT" value="false"/>
+      <option name="KOTLIN_EXPRESSION" value="false"/>
+      <option name="KOTLIN_STATEMENT" value="false"/>
+      <option name="TS_CLASS" value="false"/>
+      <option name="TS_EXPRESSION" value="false"/>
+      <option name="TS_STATEMENT" value="false"/>
+      <option name="TypeScript" value="true"/>
     </context>
   </template>
-  <template name="la" value="// language=&quot;$lang$&quot;" description="// language=&quot;&quot;" toReformat="true" toShortenFQNames="true">
-    <variable name="lang" expression="" defaultValue="" alwaysStopAt="true" />
+  <template name="la" value="// language=&quot;$lang$&quot;" description="// language=&quot;&quot;" toReformat="true"
+            toShortenFQNames="true">
+    <variable name="lang" expression="" defaultValue="" alwaysStopAt="true"/>
     <context>
-      <option name="COMPLETION" value="false" />
-      <option name="ECMAScript6" value="true" />
-      <option name="ES6_CLASS" value="false" />
-      <option name="ES6_EXPRESSION" value="false" />
-      <option name="GROOVY" value="true" />
-      <option name="GROOVY_EXPRESSION" value="false" />
-      <option name="JAVA_CODE" value="true" />
-      <option name="JAVA_COMMENT" value="false" />
-      <option name="JAVA_CONSUMER" value="false" />
-      <option name="JAVA_EXPRESSION" value="false" />
-      <option name="JAVA_SCRIPT" value="true" />
-      <option name="JAVA_STRING" value="false" />
-      <option name="JSX_HTML" value="false" />
-      <option name="JS_CLASS" value="false" />
-      <option name="JS_DOT_PROPERTY_ACCESS" value="false" />
-      <option name="JS_EXPRESSION" value="false" />
-      <option name="KOTLIN" value="true" />
-      <option name="KOTLIN_CLASS" value="false" />
-      <option name="KOTLIN_COMMENT" value="false" />
-      <option name="KOTLIN_EXPRESSION" value="false" />
-      <option name="KOTLIN_TOPLEVEL" value="false" />
-      <option name="TS_CLASS" value="false" />
-      <option name="TS_EXPRESSION" value="false" />
-      <option name="TypeScript" value="true" />
+      <option name="COMPLETION" value="false"/>
+      <option name="ECMAScript6" value="true"/>
+      <option name="ES6_CLASS" value="false"/>
+      <option name="ES6_EXPRESSION" value="false"/>
+      <option name="GROOVY" value="true"/>
+      <option name="GROOVY_EXPRESSION" value="false"/>
+      <option name="JAVA_CODE" value="true"/>
+      <option name="JAVA_COMMENT" value="false"/>
+      <option name="JAVA_CONSUMER" value="false"/>
+      <option name="JAVA_EXPRESSION" value="false"/>
+      <option name="JAVA_SCRIPT" value="true"/>
+      <option name="JAVA_STRING" value="false"/>
+      <option name="JSX_HTML" value="false"/>
+      <option name="JS_CLASS" value="false"/>
+      <option name="JS_DOT_PROPERTY_ACCESS" value="false"/>
+      <option name="JS_EXPRESSION" value="false"/>
+      <option name="KOTLIN" value="true"/>
+      <option name="KOTLIN_CLASS" value="false"/>
+      <option name="KOTLIN_COMMENT" value="false"/>
+      <option name="KOTLIN_EXPRESSION" value="false"/>
+      <option name="KOTLIN_TOPLEVEL" value="false"/>
+      <option name="TS_CLASS" value="false"/>
+      <option name="TS_EXPRESSION" value="false"/>
+      <option name="TypeScript" value="true"/>
     </context>
   </template>
-  <template name="reg" value="// region $comment$" description="// region $comment$" toReformat="true" toShortenFQNames="true">
-    <variable name="comment" expression="" defaultValue="" alwaysStopAt="true" />
+  <template name="reg" value="// region $comment$" description="// region $comment$" toReformat="true"
+            toShortenFQNames="true">
+    <variable name="comment" expression="" defaultValue="" alwaysStopAt="true"/>
     <context>
-      <option name="COMPLETION" value="false" />
-      <option name="ECMAScript6" value="true" />
-      <option name="ES6_CLASS" value="false" />
-      <option name="ES6_EXPRESSION" value="false" />
-      <option name="GROOVY" value="true" />
-      <option name="GROOVY_EXPRESSION" value="false" />
-      <option name="JAVA_CODE" value="true" />
-      <option name="JAVA_COMMENT" value="false" />
-      <option name="JAVA_CONSUMER" value="false" />
-      <option name="JAVA_EXPRESSION" value="false" />
-      <option name="JAVA_SCRIPT" value="true" />
-      <option name="JAVA_STRING" value="false" />
-      <option name="JSX_HTML" value="false" />
-      <option name="JS_CLASS" value="false" />
-      <option name="JS_DOT_PROPERTY_ACCESS" value="false" />
-      <option name="JS_EXPRESSION" value="false" />
-      <option name="KOTLIN" value="true" />
-      <option name="KOTLIN_CLASS" value="false" />
-      <option name="KOTLIN_COMMENT" value="false" />
-      <option name="KOTLIN_EXPRESSION" value="false" />
-      <option name="KOTLIN_TOPLEVEL" value="false" />
-      <option name="TS_CLASS" value="false" />
-      <option name="TS_EXPRESSION" value="false" />
-      <option name="TypeScript" value="true" />
+      <option name="COMPLETION" value="false"/>
+      <option name="ECMAScript6" value="true"/>
+      <option name="ES6_CLASS" value="false"/>
+      <option name="ES6_EXPRESSION" value="false"/>
+      <option name="GROOVY" value="true"/>
+      <option name="GROOVY_EXPRESSION" value="false"/>
+      <option name="JAVA_CODE" value="true"/>
+      <option name="JAVA_COMMENT" value="false"/>
+      <option name="JAVA_CONSUMER" value="false"/>
+      <option name="JAVA_EXPRESSION" value="false"/>
+      <option name="JAVA_SCRIPT" value="true"/>
+      <option name="JAVA_STRING" value="false"/>
+      <option name="JSX_HTML" value="false"/>
+      <option name="JS_CLASS" value="false"/>
+      <option name="JS_DOT_PROPERTY_ACCESS" value="false"/>
+      <option name="JS_EXPRESSION" value="false"/>
+      <option name="KOTLIN" value="true"/>
+      <option name="KOTLIN_CLASS" value="false"/>
+      <option name="KOTLIN_COMMENT" value="false"/>
+      <option name="KOTLIN_EXPRESSION" value="false"/>
+      <option name="KOTLIN_TOPLEVEL" value="false"/>
+      <option name="TS_CLASS" value="false"/>
+      <option name="TS_EXPRESSION" value="false"/>
+      <option name="TypeScript" value="true"/>
     </context>
   </template>
-  <template name="end" value="// endregion $comment$" description="// endregion $comment$" toReformat="true" toShortenFQNames="true">
-    <variable name="comment" expression="" defaultValue="" alwaysStopAt="true" />
+  <template name="end" value="// endregion $comment$" description="// endregion $comment$" toReformat="true"
+            toShortenFQNames="true">
+    <variable name="comment" expression="" defaultValue="" alwaysStopAt="true"/>
     <context>
-      <option name="COMPLETION" value="false" />
-      <option name="ECMAScript6" value="true" />
-      <option name="ES6_CLASS" value="false" />
-      <option name="ES6_EXPRESSION" value="false" />
-      <option name="GROOVY" value="true" />
-      <option name="GROOVY_EXPRESSION" value="false" />
-      <option name="JAVA_CODE" value="true" />
-      <option name="JAVA_COMMENT" value="false" />
-      <option name="JAVA_CONSUMER" value="false" />
-      <option name="JAVA_EXPRESSION" value="false" />
-      <option name="JAVA_SCRIPT" value="true" />
-      <option name="JAVA_STRING" value="false" />
-      <option name="JSX_HTML" value="false" />
-      <option name="JS_CLASS" value="false" />
-      <option name="JS_DOT_PROPERTY_ACCESS" value="false" />
-      <option name="JS_EXPRESSION" value="false" />
-      <option name="KOTLIN" value="true" />
-      <option name="KOTLIN_CLASS" value="false" />
-      <option name="KOTLIN_COMMENT" value="false" />
-      <option name="KOTLIN_EXPRESSION" value="false" />
-      <option name="KOTLIN_TOPLEVEL" value="false" />
-      <option name="TS_CLASS" value="false" />
-      <option name="TS_EXPRESSION" value="false" />
-      <option name="TypeScript" value="true" />
+      <option name="COMPLETION" value="false"/>
+      <option name="ECMAScript6" value="true"/>
+      <option name="ES6_CLASS" value="false"/>
+      <option name="ES6_EXPRESSION" value="false"/>
+      <option name="GROOVY" value="true"/>
+      <option name="GROOVY_EXPRESSION" value="false"/>
+      <option name="JAVA_CODE" value="true"/>
+      <option name="JAVA_COMMENT" value="false"/>
+      <option name="JAVA_CONSUMER" value="false"/>
+      <option name="JAVA_EXPRESSION" value="false"/>
+      <option name="JAVA_SCRIPT" value="true"/>
+      <option name="JAVA_STRING" value="false"/>
+      <option name="JSX_HTML" value="false"/>
+      <option name="JS_CLASS" value="false"/>
+      <option name="JS_DOT_PROPERTY_ACCESS" value="false"/>
+      <option name="JS_EXPRESSION" value="false"/>
+      <option name="KOTLIN" value="true"/>
+      <option name="KOTLIN_CLASS" value="false"/>
+      <option name="KOTLIN_COMMENT" value="false"/>
+      <option name="KOTLIN_EXPRESSION" value="false"/>
+      <option name="KOTLIN_TOPLEVEL" value="false"/>
+      <option name="TS_CLASS" value="false"/>
+      <option name="TS_EXPRESSION" value="false"/>
+      <option name="TypeScript" value="true"/>
     </context>
   </template>
-  <template name="hr" value="/* ******************* $text$ ******************* */" description="/* ******************* $comm$ ******************* */ 20*" toReformat="false" toShortenFQNames="true">
-    <variable name="text" expression="" defaultValue="" alwaysStopAt="true" />
+  <template name="hr" value="/* ******************* $text$ ******************* */"
+            description="/* ******************* $comm$ ******************* */ 20*" toReformat="false"
+            toShortenFQNames="true">
+    <variable name="text" expression="" defaultValue="" alwaysStopAt="true"/>
     <context>
-      <option name="COMPLETION" value="false" />
-      <option name="ECMAScript6" value="true" />
-      <option name="ES6_CLASS" value="false" />
-      <option name="ES6_EXPRESSION" value="false" />
-      <option name="GROOVY" value="true" />
-      <option name="GROOVY_EXPRESSION" value="false" />
-      <option name="JAVA_CODE" value="true" />
-      <option name="JAVA_COMMENT" value="false" />
-      <option name="JAVA_CONSUMER" value="false" />
-      <option name="JAVA_EXPRESSION" value="false" />
-      <option name="JAVA_SCRIPT" value="true" />
-      <option name="JAVA_STRING" value="false" />
-      <option name="JSX_HTML" value="false" />
-      <option name="JS_CLASS" value="false" />
-      <option name="JS_DOT_PROPERTY_ACCESS" value="false" />
-      <option name="JS_EXPRESSION" value="false" />
-      <option name="KOTLIN" value="true" />
-      <option name="KOTLIN_CLASS" value="false" />
-      <option name="KOTLIN_COMMENT" value="false" />
-      <option name="KOTLIN_EXPRESSION" value="false" />
-      <option name="KOTLIN_TOPLEVEL" value="false" />
-      <option name="TS_CLASS" value="false" />
-      <option name="TS_EXPRESSION" value="false" />
-      <option name="TypeScript" value="true" />
+      <option name="COMPLETION" value="false"/>
+      <option name="ECMAScript6" value="true"/>
+      <option name="ES6_CLASS" value="false"/>
+      <option name="ES6_EXPRESSION" value="false"/>
+      <option name="GROOVY" value="true"/>
+      <option name="GROOVY_EXPRESSION" value="false"/>
+      <option name="JAVA_CODE" value="true"/>
+      <option name="JAVA_COMMENT" value="false"/>
+      <option name="JAVA_CONSUMER" value="false"/>
+      <option name="JAVA_EXPRESSION" value="false"/>
+      <option name="JAVA_SCRIPT" value="true"/>
+      <option name="JAVA_STRING" value="false"/>
+      <option name="JSX_HTML" value="false"/>
+      <option name="JS_CLASS" value="false"/>
+      <option name="JS_DOT_PROPERTY_ACCESS" value="false"/>
+      <option name="JS_EXPRESSION" value="false"/>
+      <option name="KOTLIN" value="true"/>
+      <option name="KOTLIN_CLASS" value="false"/>
+      <option name="KOTLIN_COMMENT" value="false"/>
+      <option name="KOTLIN_EXPRESSION" value="false"/>
+      <option name="KOTLIN_TOPLEVEL" value="false"/>
+      <option name="TS_CLASS" value="false"/>
+      <option name="TS_EXPRESSION" value="false"/>
+      <option name="TypeScript" value="true"/>
     </context>
   </template>
 </templateSet>
\ No newline at end of file
diff --git a/src/main/resources/liveTemplates/show-comment-xml.xml b/src/main/resources/liveTemplates/show-comment-xml.xml
index dbcddc9..b31909d 100644
--- a/src/main/resources/liveTemplates/show-comment-xml.xml
+++ b/src/main/resources/liveTemplates/show-comment-xml.xml
@@ -1,12 +1,13 @@
 <templateSet group="show-comment-xml">
-  <template name="doc" value="    &lt;!-- $SELECTION$ --&gt;" description="&lt;!--  --&gt;" toReformat="true" toShortenFQNames="true">
+  <template name="doc" value="    &lt;!-- $SELECTION$ --&gt;" description="&lt;!--  --&gt;" toReformat="true"
+            toShortenFQNames="true">
     <context>
-      <option name="HTML" value="true" />
-      <option name="HTML_TEXT" value="false" />
-      <option name="JSP" value="true" />
-      <option name="MAVEN" value="true" />
-      <option name="XML" value="true" />
-      <option name="XSL_TEXT" value="false" />
+      <option name="HTML" value="true"/>
+      <option name="HTML_TEXT" value="false"/>
+      <option name="JSP" value="true"/>
+      <option name="MAVEN" value="true"/>
+      <option name="XML" value="true"/>
+      <option name="XSL_TEXT" value="false"/>
     </context>
   </template>
 </templateSet>
\ No newline at end of file
diff --git a/src/test/java/io/github/linwancen/plugin/show/demo/HTML.html b/src/test/java/io/github/linwancen/plugin/show/demo/HTML.html
index bab241a..bea4bba 100644
--- a/src/test/java/io/github/linwancen/plugin/show/demo/HTML.html
+++ b/src/test/java/io/github/linwancen/plugin/show/demo/HTML.html
@@ -1,25 +1,25 @@
 <!DOCTYPE html>
 <html lang="en">
 <head>
-    <meta charset="UTF-8">
-    <title>Title</title>
+  <meta charset="UTF-8">
+  <title>Title</title>
 </head>
 <body>
 
 </body>
 <script type="javascript">
-    lineBlock(isNotDoc)
-    lineBlock(docVal)
+  lineBlock(isNotDoc)
+  lineBlock(docVal)
 
-    // isNotDoc
-    const isNotDoc = ""
+  // isNotDoc
+  const isNotDoc = ""
 
-    /** docVal */
-    const docVal = ""
+  /** docVal */
+  const docVal = ""
 
-    /*** lineBlock ***/
-    function lineBlock(t) {
-        return t
-    }
+  /*** lineBlock ***/
+  function lineBlock(t) {
+    return t
+  }
 </script>
 </html>
\ No newline at end of file
diff --git a/src/test/java/io/github/linwancen/plugin/show/demo/JavaScript.js b/src/test/java/io/github/linwancen/plugin/show/demo/JavaScript.js
index d621bed..e44def3 100644
--- a/src/test/java/io/github/linwancen/plugin/show/demo/JavaScript.js
+++ b/src/test/java/io/github/linwancen/plugin/show/demo/JavaScript.js
@@ -1,4 +1,3 @@
-
 lineBlock(isNotDoc)
 lineBlock(docVal)
 block()
@@ -11,7 +10,7 @@ const docVal = ""
 
 /*** lineBlock ***/
 function lineBlock(t) {
-    return t
+  return t
 }
 
 /*****
@@ -19,5 +18,5 @@ function lineBlock(t) {
  ***** 2
  *****/
 function block(t) {
-    return t
+  return t
 }
\ No newline at end of file
diff --git a/src/test/java/io/github/linwancen/plugin/show/demo/JavaScriptObject.js b/src/test/java/io/github/linwancen/plugin/show/demo/JavaScriptObject.js
index ce1531c..7b489a4 100644
--- a/src/test/java/io/github/linwancen/plugin/show/demo/JavaScriptObject.js
+++ b/src/test/java/io/github/linwancen/plugin/show/demo/JavaScriptObject.js
@@ -1,4 +1,3 @@
-
 obj.isA(obj.getB())
 obj.setA(obj.getB())
 obj.setB(obj.a)
@@ -15,29 +14,29 @@ let b = obj
 
 /** obj1 */
 let obj = {
-    /** a */
-    "a":"A",
-    /** b */
-    "b":"B",
-    /** sub */
-    "sub":{
-        /** subKey */
-        "subKey":"subVal"
-    },
-    /** isA */
-    isA: function (t) {
-        return t
-    },
-    /** setA */
-    setA: function (t) {
-        return t
-    },
-    /** getB */
-    getB: function (t) {
-        return t
-    },
-    /** setB */
-    setB: function (t) {
-        return t
-    },
+  /** a */
+  "a": "A",
+  /** b */
+  "b": "B",
+  /** sub */
+  "sub": {
+    /** subKey */
+    "subKey": "subVal"
+  },
+  /** isA */
+  isA: function (t) {
+    return t
+  },
+  /** setA */
+  setA: function (t) {
+    return t
+  },
+  /** getB */
+  getB: function (t) {
+    return t
+  },
+  /** setB */
+  setB: function (t) {
+    return t
+  },
 }
\ No newline at end of file
diff --git a/src/test/java/io/github/linwancen/plugin/show/demo/Python.py b/src/test/java/io/github/linwancen/plugin/show/demo/Python.py
index 2f74150..2d12b24 100644
--- a/src/test/java/io/github/linwancen/plugin/show/demo/Python.py
+++ b/src/test/java/io/github/linwancen/plugin/show/demo/Python.py
@@ -13,6 +13,7 @@ class Type:
     # Type init
     def __init__(self):
         pass
+
     # field1
     field = ""
 
diff --git a/src/test/java/io/github/linwancen/plugin/show/demo/java/InDoc.java b/src/test/java/io/github/linwancen/plugin/show/demo/java/InDoc.java
index 6d5e739..953ff1c 100644
--- a/src/test/java/io/github/linwancen/plugin/show/demo/java/InDoc.java
+++ b/src/test/java/io/github/linwancen/plugin/show/demo/java/InDoc.java
@@ -2,7 +2,7 @@ package io.github.linwancen.plugin.show.demo.java;
 
 /**
  * InDoc
- *
+ * <p>
  * {@link InDoc}
  * {@link InDoc#field}
  * {@link InDoc#method1}
diff --git a/src/test/java/io/github/linwancen/plugin/show/demo/json/nested-Pojo.json b/src/test/java/io/github/linwancen/plugin/show/demo/json/nested-Pojo.json
index b75e80d..7ff2f69 100644
--- a/src/test/java/io/github/linwancen/plugin/show/demo/json/nested-Pojo.json
+++ b/src/test/java/io/github/linwancen/plugin/show/demo/json/nested-Pojo.json
@@ -1,8 +1,7 @@
 {
-  "nestedClass":
-    {
-      "nestedClass2": {
-        "a": ""
-      }
+  "nestedClass": {
+    "nestedClass2": {
+      "a": ""
     }
+  }
 }
\ No newline at end of file
diff --git a/src/test/java/io/github/linwancen/plugin/show/demo/sql.sql b/src/test/java/io/github/linwancen/plugin/show/demo/sql.sql
index ea4a16e..089f1c6 100644
--- a/src/test/java/io/github/linwancen/plugin/show/demo/sql.sql
+++ b/src/test/java/io/github/linwancen/plugin/show/demo/sql.sql
@@ -1 +1,3 @@
-select * from NewTable where Column1 is not null ;
\ No newline at end of file
+select *
+from NewTable
+where Column1 is not null;
\ No newline at end of file