diff --git a/client/src/main/java/com/alibaba/nacos/client/naming/NacosNamingService.java b/client/src/main/java/com/alibaba/nacos/client/naming/NacosNamingService.java
index dc2c823bc..4c61a73c5 100644
--- a/client/src/main/java/com/alibaba/nacos/client/naming/NacosNamingService.java
+++ b/client/src/main/java/com/alibaba/nacos/client/naming/NacosNamingService.java
@@ -19,7 +19,6 @@ import com.alibaba.nacos.api.PropertyKeyConst;
 import com.alibaba.nacos.api.common.Constants;
 import com.alibaba.nacos.api.exception.NacosException;
 import com.alibaba.nacos.api.naming.NamingService;
-import com.alibaba.nacos.api.naming.PreservedMetadataKeys;
 import com.alibaba.nacos.api.naming.listener.EventListener;
 import com.alibaba.nacos.api.naming.pojo.Instance;
 import com.alibaba.nacos.api.naming.pojo.ListView;
@@ -35,11 +34,14 @@ import com.alibaba.nacos.client.naming.net.NamingProxy;
 import com.alibaba.nacos.client.naming.utils.CollectionUtils;
 import com.alibaba.nacos.client.naming.utils.InitUtils;
 import com.alibaba.nacos.client.naming.utils.UtilAndComs;
-import com.alibaba.nacos.client.utils.*;
+import com.alibaba.nacos.client.utils.StringUtils;
 import org.apache.commons.lang3.BooleanUtils;
 import org.apache.commons.lang3.math.NumberUtils;
 
-import java.util.*;
+import java.util.ArrayList;
+import java.util.Iterator;
+import java.util.List;
+import java.util.Properties;
 import java.util.concurrent.TimeUnit;
 
 /**