Fix repeat creating Gson
diff --git a/shardingsphere-elasticjob-cloud-ui/shardingsphere-elasticjob-cloud-ui-backend/src/main/java/org/apache/shardingsphere/elasticjob/cloud/ui/security/AuthenticationFilter.java b/shardingsphere-elasticjob-cloud-ui/shardingsphere-elasticjob-cloud-ui-backend/src/main/java/org/apache/shardingsphere/elasticjob/cloud/ui/security/AuthenticationFilter.java
index d550fa5..89cc404 100644
--- a/shardingsphere-elasticjob-cloud-ui/shardingsphere-elasticjob-cloud-ui-backend/src/main/java/org/apache/shardingsphere/elasticjob/cloud/ui/security/AuthenticationFilter.java
+++ b/shardingsphere-elasticjob-cloud-ui/shardingsphere-elasticjob-cloud-ui-backend/src/main/java/org/apache/shardingsphere/elasticjob/cloud/ui/security/AuthenticationFilter.java
@@ -94,6 +94,6 @@
     private void respondWithUnauthorized(final HttpServletResponse httpResponse) throws IOException {
         httpResponse.setContentType("application/json");
         httpResponse.setCharacterEncoding("UTF-8");
-        httpResponse.getWriter().write(new Gson().toJson(ResponseResultUtil.handleUnauthorizedException("Unauthorized.")));
+        httpResponse.getWriter().write(gson.toJson(ResponseResultUtil.handleUnauthorizedException("Unauthorized.")));
     }
 }
diff --git a/shardingsphere-elasticjob-lite-ui/shardingsphere-elasticjob-lite-ui-backend/src/main/java/org/apache/shardingsphere/elasticjob/lite/ui/security/AuthenticationFilter.java b/shardingsphere-elasticjob-lite-ui/shardingsphere-elasticjob-lite-ui-backend/src/main/java/org/apache/shardingsphere/elasticjob/lite/ui/security/AuthenticationFilter.java
index 23901af..b299e82 100644
--- a/shardingsphere-elasticjob-lite-ui/shardingsphere-elasticjob-lite-ui-backend/src/main/java/org/apache/shardingsphere/elasticjob/lite/ui/security/AuthenticationFilter.java
+++ b/shardingsphere-elasticjob-lite-ui/shardingsphere-elasticjob-lite-ui-backend/src/main/java/org/apache/shardingsphere/elasticjob/lite/ui/security/AuthenticationFilter.java
@@ -94,6 +94,6 @@
     private void respondWithUnauthorized(final HttpServletResponse httpResponse) throws IOException {
         httpResponse.setContentType("application/json");
         httpResponse.setCharacterEncoding("UTF-8");
-        httpResponse.getWriter().write(new Gson().toJson(ResponseResultUtil.handleUnauthorizedException("Unauthorized.")));
+        httpResponse.getWriter().write(gson.toJson(ResponseResultUtil.handleUnauthorizedException("Unauthorized.")));
     }
 }