diff --git a/src/main/java/org/apache/rocketmq/console/service/impl/TopicServiceImpl.java b/src/main/java/org/apache/rocketmq/console/service/impl/TopicServiceImpl.java
index 7d9a947..a3ee18b 100644
--- a/src/main/java/org/apache/rocketmq/console/service/impl/TopicServiceImpl.java
+++ b/src/main/java/org/apache/rocketmq/console/service/impl/TopicServiceImpl.java
@@ -21,7 +21,10 @@ import com.google.common.base.Throwables;
 import com.google.common.collect.Lists;
 import com.google.common.collect.Sets;
 
-import java.util.*;
+import java.util.Arrays;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Set;
 
 import org.apache.commons.lang3.StringUtils;
 import org.apache.rocketmq.client.producer.DefaultMQProducer;