[ISSUE alibaba#3576] [Enhancement] Adding the destroy lifecycle method on NamingMaintainService (alibaba#3985)

Author: realJackSun

api/src/main/java/com/alibaba/nacos/api/naming/NamingMaintainService.java

@@ -167,4 +167,10 @@ void updateService(String serviceName, String groupName, float protectThreshold,
      */
     void updateService(Service service, AbstractSelector selector) throws NacosException;
 
+    /**
+     * Shutdown the resource service.
+     *
+     * @throws NacosException exception.
+     */
+    void shutDown() throws NacosException;
 }

client/src/main/java/com/alibaba/nacos/client/naming/NacosNamingMaintainService.java

@@ -173,4 +173,8 @@ public void updateService(Service service, AbstractSelector selector) throws Nac
         serverProxy.updateService(service, selector);
     }
 
+    @Override
+    public void shutDown() throws NacosException {
+        serverProxy.shutdown();
+    }
 }

test/src/test/java/com/alibaba/nacos/test/naming/NamingMaintainService_ITCase.java

@@ -29,6 +29,7 @@
 import com.alibaba.nacos.api.selector.NoneSelector;
 import com.alibaba.nacos.sys.utils.ApplicationUtils;
 import com.alibaba.nacos.test.BaseTest;
+import org.junit.After;
 import org.junit.Assert;
 import org.junit.Before;
 import org.junit.Test;
@@ -163,5 +164,10 @@ public void deleteService() throws NacosException {
 
         Assert.assertTrue(namingMaintainService.deleteService(serviceName));
     }
-
+    
+    @After
+    public void tearDown() throws NacosException {
+        namingMaintainService.shutDown();
+        namingService.shutDown();
+    }
 }