Polish /apache#3942 : Refactor implementation

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

@@ -0,0 +1,47 @@
+package org.apache.dubbo.registry.client;/*
+ * 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.
+ */
+
+import org.apache.dubbo.common.URL;
+import org.apache.dubbo.common.extension.SPI;
+
+import static org.apache.dubbo.common.extension.ExtensionLoader.getExtensionLoader;
+
+/**
+ * The factory class to create an instance of {@link ServiceDiscoveryFactory} based on Event-Publishing as the default
+ * {@link SPI} implementation
+ *
+ * @see ServiceDiscoveryFactory
+ * @see EventPublishingServiceDiscovery
+ * @see ServiceDiscovery
+ * @since 2.7.3
+ */
+public class EventPublishingServiceDiscoveryFactory implements ServiceDiscoveryFactory {
+
+    private static final Class<ServiceDiscoveryFactory> FACTORY_CLASS = ServiceDiscoveryFactory.class;
+
+    @Override
+    public ServiceDiscovery create(URL connectionURL) {
+        String protocol = connectionURL.getProtocol();
+        ServiceDiscoveryFactory serviceDiscoveryFactory = loadFactoryByProtocol(protocol);
+        ServiceDiscovery originalServiceDiscovery = serviceDiscoveryFactory.create(connectionURL);
+        return new EventPublishingServiceDiscovery(originalServiceDiscovery);
+    }
+
+    protected ServiceDiscoveryFactory loadFactoryByProtocol(String protocol) {
+        return getExtensionLoader(FACTORY_CLASS).getExtension(protocol);
+    }
+}

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

@@ -19,7 +19,6 @@
 import org.apache.dubbo.common.URL;
 import org.apache.dubbo.common.extension.SPI;
 
-import static java.lang.Integer.compare;
 import static org.apache.dubbo.common.extension.ExtensionLoader.getExtensionLoader;
 
 /**
@@ -28,46 +27,17 @@
  * @see ServiceDiscovery
  * @since 2.7.3
  */
-@SPI("default")
-public interface ServiceDiscoveryFactory extends Comparable<ServiceDiscoveryFactory> {
+@SPI("event-publishing")
+public interface ServiceDiscoveryFactory {
 
     /**
-     * It indicates the current implementation supports or not in the specified {@link URL connnection url}.
+     * Creates an instance of {@link ServiceDiscovery}.
      *
      * @param connectionURL the  {@link URL connection url}
-     * @return if supports, return <code>true</code>, or <code>false</code>
-     */
-    boolean supports(URL connectionURL);
-
-    /**
-     * Creates an instance of {@link ServiceDiscovery} if {@link #supports(URL)} returns <code>true</code>,
-     *
-     * @param connectionURL the  {@link URL connection url}
-     * @return an instance of {@link ServiceDiscovery} if supported, or <code>null</code>
+     * @return an instance of {@link ServiceDiscovery}
      */
     ServiceDiscovery create(URL connectionURL);
 
-    /**
-     * The priority of current {@link ServiceDiscoveryFactory}
-     *
-     * @return The {@link Integer#MIN_VALUE minimum integer} indicates the highest priority, in contrast，
-     * the lowest priority is {@link Integer#MAX_VALUE the maximum integer}
-     */
-    default int getPriority() {
-        return Integer.MAX_VALUE;
-    }
-
-    /**
-     * Compares its priority
-     *
-     * @param that {@link ServiceDiscovery}
-     * @return
-     */
-    @Override
-    default int compareTo(ServiceDiscoveryFactory that) {
-        return compare(this.getPriority(), that.getPriority());
-    }
-
     /**
      * Get the default extension of {@link ServiceDiscoveryFactory}
      *

dubbo-registry/dubbo-registry-api/src/main/resources/META-INF/dubbo/internal/org.apache.dubbo.registry.client.ServiceDiscoveryFactory

@@ -1 +1 @@
-default=org.apache.dubbo.registry.client.DefaultServiceDiscoveryFactory
+event-publishing=org.apache.dubbo.registry.client.EventPublishingServiceDiscoveryFactory

dubbo-registry/dubbo-registry-api/src/test/java/org/apache/dubbo/registry/client/InMemoryServiceDiscoveryFactory.java

@@ -26,11 +26,6 @@
  */
 public class InMemoryServiceDiscoveryFactory implements ServiceDiscoveryFactory {
 
-    @Override
-    public boolean supports(URL connectionURL) {
-        return "in-memory".equalsIgnoreCase(connectionURL.getProtocol());
-    }
-
     @Override
     public ServiceDiscovery create(URL connectionURL) {
         return new InMemoryServiceDiscovery();

dubbo-registry/dubbo-registry-api/src/test/java/org/apache/dubbo/registry/client/ServiceDiscoveryFactoryTest.java

@@ -23,8 +23,6 @@
 
 import static org.apache.dubbo.common.URL.valueOf;
 import static org.junit.jupiter.api.Assertions.assertEquals;
-import static org.junit.jupiter.api.Assertions.assertFalse;
-import static org.junit.jupiter.api.Assertions.assertTrue;
 
 /**
  * {@link ServiceDiscoveryFactory} Test
@@ -46,23 +44,12 @@ public void init() {
 
     @Test
     public void testClass() {
-        assertEquals(DefaultServiceDiscoveryFactory.class, serviceDiscoveryFactory.getClass());
-    }
-
-    @Test
-    public void testSupports() {
-        assertFalse(serviceDiscoveryFactory.supports(dubboURL));
-        assertTrue(serviceDiscoveryFactory.supports(inMemoryURL));
+        assertEquals(EventPublishingServiceDiscoveryFactory.class, serviceDiscoveryFactory.getClass());
     }
 
     @Test
     public void testCreate() {
         ServiceDiscovery serviceDiscovery = serviceDiscoveryFactory.create(inMemoryURL);
         assertEquals(EventPublishingServiceDiscovery.class, serviceDiscovery.getClass());
     }
-
-    @Test
-    public void testPriority() {
-        assertEquals(Integer.MAX_VALUE, serviceDiscoveryFactory.getPriority());
-    }
 }

dubbo-registry/dubbo-registry-api/src/test/resources/META-INF/services/org.apache.dubbo.registry.client.ServiceDiscoveryFactory

@@ -1 +1 @@
-org.apache.dubbo.registry.client.InMemoryServiceDiscoveryFactory
+in-memory=org.apache.dubbo.registry.client.InMemoryServiceDiscoveryFactory

dubbo-registry/dubbo-registry-zookeeper/src/main/java/org/apache/dubbo/registry/zookeeper/ZookeeperServiceDiscoveryFactory.java

@@ -28,11 +28,6 @@
  */
 public class ZookeeperServiceDiscoveryFactory implements ServiceDiscoveryFactory {
 
-    @Override
-    public boolean supports(URL connectionURL) {
-        return "zookeeper".equalsIgnoreCase(connectionURL.getProtocol());
-    }
-
     @Override
     public ServiceDiscovery create(URL connectionURL) {
         try {

dubbo-registry/dubbo-registry-zookeeper/src/main/resources/META-INF/dubbo/internal/org.apache.dubbo.registry.client.ServiceDiscoveryFactory

@@ -0,0 +1 @@
+zookeeper=org.apache.dubbo.registry.zookeeper.ZookeeperServiceDiscoveryFactory