Add BlockException parameter to UrlBlockHandler.blocked() method

sentinel-adapter/sentinel-web-servlet/src/main/java/com/alibaba/csp/sentinel/adapter/servlet/CommonFilter.java

@@ -77,7 +77,7 @@ public class CommonFilter implements Filter {
         } catch (BlockException e) {
             HttpServletResponse sResponse = (HttpServletResponse)response;
             // Return the block page, or redirect to another URL.
-            WebCallbackManager.getUrlBlockHandler().blocked(sRequest, sResponse);
+            WebCallbackManager.getUrlBlockHandler().blocked(sRequest, sResponse, e);
         } catch (IOException e2) {
             Tracer.trace(e2);
             throw e2;

sentinel-adapter/sentinel-web-servlet/src/main/java/com/alibaba/csp/sentinel/adapter/servlet/CommonTotalFilter.java

@@ -62,7 +62,7 @@ public class CommonTotalFilter implements Filter {
             chain.doFilter(request, response);
         } catch (BlockException e) {
             HttpServletResponse sResponse = (HttpServletResponse)response;
-            WebCallbackManager.getUrlBlockHandler().blocked(sRequest, sResponse);
+            WebCallbackManager.getUrlBlockHandler().blocked(sRequest, sResponse, e);
         } catch (IOException e2) {
             Tracer.trace(e2);
             throw e2;

sentinel-adapter/sentinel-web-servlet/src/main/java/com/alibaba/csp/sentinel/adapter/servlet/callback/DefaultUrlBlockHandler.java

@@ -21,6 +21,7 @@ import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
 
 import com.alibaba.csp.sentinel.adapter.servlet.util.FilterUtil;
+import com.alibaba.csp.sentinel.slots.block.BlockException;
 
 /***
  * The default {@link UrlBlockHandler}.
@@ -30,7 +31,8 @@ import com.alibaba.csp.sentinel.adapter.servlet.util.FilterUtil;
 public class DefaultUrlBlockHandler implements UrlBlockHandler {
 
     @Override
-    public void blocked(HttpServletRequest request, HttpServletResponse response) throws IOException {
+    public void blocked(HttpServletRequest request, HttpServletResponse response, BlockException ex)
+        throws IOException {
         // Directly redirect to the default flow control (blocked) page or customized block page.
         FilterUtil.blockRequest(request, response);
     }

sentinel-adapter/sentinel-web-servlet/src/main/java/com/alibaba/csp/sentinel/adapter/servlet/callback/UrlBlockHandler.java

@@ -20,6 +20,8 @@ import java.io.IOException;
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
 
+import com.alibaba.csp.sentinel.slots.block.BlockException;
+
 /***
  * The URL block handler handles requests when blocked.
  *
@@ -32,7 +34,8 @@ public interface UrlBlockHandler {
      *
      * @param request  Servlet request
      * @param response Servlet response
+     * @param ex       the block exception.
      * @throws IOException some error occurs
      */
-    void blocked(HttpServletRequest request, HttpServletResponse response) throws IOException;
+    void blocked(HttpServletRequest request, HttpServletResponse response, BlockException ex) throws IOException;
 }