优化代码，支持防盗链功能

devttl-common/src/main/java/com/devttl/common/filter/RefererFilter.java

@@ -0,0 +1,63 @@
+package com.devttl.common.filter;
+
+import jakarta.servlet.*;
+import jakarta.servlet.http.HttpServletRequest;
+import jakarta.servlet.http.HttpServletResponse;
+
+import java.io.IOException;
+import java.util.Arrays;
+import java.util.List;
+
+/**
+ * 防盗链过滤器
+ *
+ * @author ruoyi
+ */
+public class RefererFilter implements Filter {
+    /**
+     * 允许的域名列表
+     */
+    public List<String> allowedDomains;
+
+    @Override
+    public void init(FilterConfig filterConfig) throws ServletException {
+        String domains = filterConfig.getInitParameter("allowedDomains");
+        this.allowedDomains = Arrays.asList(domains.split(","));
+    }
+
+    @Override
+    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
+            throws IOException, ServletException {
+        HttpServletRequest req = (HttpServletRequest) request;
+        HttpServletResponse resp = (HttpServletResponse) response;
+
+        String referer = req.getHeader("Referer");
+
+        // 如果Referer为空，拒绝访问
+        if (referer == null || referer.isEmpty()) {
+            resp.sendError(HttpServletResponse.SC_FORBIDDEN, "Access denied: Referer header is required");
+            return;
+        }
+
+        // 检查Referer是否在允许的域名列表中
+        boolean allowed = false;
+        for (String domain : allowedDomains) {
+            if (referer.contains(domain)) {
+                allowed = true;
+                break;
+            }
+        }
+
+        // 根据检查结果决定是否放行
+        if (allowed) {
+            chain.doFilter(request, response);
+        } else {
+            resp.sendError(HttpServletResponse.SC_FORBIDDEN, "Access denied: Referer '" + referer + "' is not allowed");
+        }
+    }
+
+    @Override
+    public void destroy() {
+
+    }
+}