Polish apache#3984 : Refactor implementation by the event/listener ab…

…stract

dubbo-registry/dubbo-registry-api/src/main/java/org/apache/dubbo/registry/client/DefaultPage.java → dubbo-common/src/main/java/org/apache/dubbo/common/utils/DefaultPage.java

@@ -14,7 +14,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package org.apache.dubbo.registry.client;
+package org.apache.dubbo.common.utils;
 
 import java.io.Serializable;
 import java.util.List;

dubbo-registry/dubbo-registry-api/src/main/java/org/apache/dubbo/registry/client/Page.java → dubbo-common/src/main/java/org/apache/dubbo/common/utils/Page.java

@@ -14,7 +14,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package org.apache.dubbo.registry.client;
+package org.apache.dubbo.common.utils;
 
 import java.util.List;
 

dubbo-registry/dubbo-registry-api/src/test/java/org/apache/dubbo/registry/client/DefaultPageTest.java → dubbo-common/src/test/java/org/apache/dubbo/common/utils/DefaultPageTest.java

@@ -14,7 +14,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package org.apache.dubbo.registry.client;
+package org.apache.dubbo.common.utils;
 
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;

dubbo-registry/dubbo-registry-api/src/main/java/org/apache/dubbo/registry/client/CompositeServiceDiscovery.java

@@ -16,6 +16,8 @@
  */
 package org.apache.dubbo.registry.client;
 
+import org.apache.dubbo.common.utils.DefaultPage;
+import org.apache.dubbo.common.utils.Page;
 import org.apache.dubbo.registry.client.event.ServiceDiscoveryChangeListener;
 
 import java.util.Collection;
@@ -99,9 +101,9 @@ public Page<ServiceInstance> getInstances(String serviceName, int offset, int re
     }
 
     @Override
-    public void registerListener(String serviceName, ServiceDiscoveryChangeListener listener) {
+    public void registerListener(ServiceDiscoveryChangeListener listener) {
         for (ServiceDiscovery serviceDiscovery : serviceDiscoveries) {
-            serviceDiscovery.registerListener(serviceName, listener);
+            serviceDiscovery.registerListener(listener);
         }
     }
 

dubbo-registry/dubbo-registry-api/src/main/java/org/apache/dubbo/registry/client/ServiceDiscovery.java

@@ -16,6 +16,8 @@
  */
 package org.apache.dubbo.registry.client;
 
+import org.apache.dubbo.common.utils.DefaultPage;
+import org.apache.dubbo.common.utils.Page;
 import org.apache.dubbo.registry.client.event.ServiceDiscoveryChangeListener;
 
 import java.util.ArrayList;
@@ -162,10 +164,9 @@ default Map<String, Page<ServiceInstance>> getInstances(Iterable<String> service
     /**
      * Register {@link ServiceDiscoveryChangeListener the service chagne event listener}
      *
-     * @param serviceName the name of service that is required to be listened
      * @param listener    {@link ServiceDiscoveryChangeListener the service change event listener}
      */
-    void registerListener(String serviceName, ServiceDiscoveryChangeListener listener);
+    void registerListener(ServiceDiscoveryChangeListener listener);
 
     /**
      * The priority of current {@link ServiceDiscovery}

dubbo-registry/dubbo-registry-api/src/main/java/org/apache/dubbo/registry/client/event/ServiceDiscoveryChangeEvent.java

@@ -16,6 +16,7 @@
  */
 package org.apache.dubbo.registry.client.event;
 
+import org.apache.dubbo.common.event.Event;
 import org.apache.dubbo.registry.client.ServiceInstance;
 
 import java.util.Collection;
@@ -27,10 +28,9 @@
  * The Service Discovery Change {@link EventObject Event}
  *
  * @see ServiceDiscoveryChangeListener
- * @see ServiceDiscoveryChangeEventNotifier
  * @since 2.7.2
  */
-public class ServiceDiscoveryChangeEvent extends EventObject {
+public class ServiceDiscoveryChangeEvent extends Event {
 
     private final String serviceName;
 

dubbo-registry/dubbo-registry-api/src/main/java/org/apache/dubbo/registry/client/event/ServiceDiscoveryChangeListener.java

@@ -16,16 +16,15 @@
  */
 package org.apache.dubbo.registry.client.event;
 
-import java.util.EventListener;
+import org.apache.dubbo.common.event.EventListener;
 
 /**
  * The Service Discovery Change {@link EventListener Event Listener}
  *
  * @see ServiceDiscoveryChangeEvent
- * @see ServiceDiscoveryChangeEventNotifier
  * @since 2.7.2
  */
-public interface ServiceDiscoveryChangeListener extends EventListener {
+public interface ServiceDiscoveryChangeListener extends EventListener<ServiceDiscoveryChangeEvent> {
 
     /**
      * On {@link ServiceDiscoveryChangeEvent the service change event}

dubbo-registry/dubbo-registry-api/src/main/java/org/apache/dubbo/registry/metadata/DiscoverableMetadataService.java

@@ -0,0 +1,37 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.dubbo.registry.metadata;
+
+import org.apache.dubbo.common.metadata.AbstractLocalMetadataService;
+import org.apache.dubbo.common.metadata.MetadataService;
+import org.apache.dubbo.registry.client.ServiceDiscovery;
+
+/**
+ * {@link MetadataService} implementation works
+ *
+ * @since 2.7.2
+ */
+public class DiscoverableMetadataService extends AbstractLocalMetadataService {
+
+    private final ServiceDiscovery serviceDiscovery;
+
+    public DiscoverableMetadataService(String serviceName, ServiceDiscovery serviceDiscovery) {
+        super(serviceName);
+        this.serviceDiscovery = serviceDiscovery;
+    }
+
+}