Dubbo cloud native (#4949)

* Polish #4542 : [Enhancement] Adapt the Java standard Event/Listener mechanism

* Polish #4541 : [Feature] Add local File System DynamicConfigurationFactory‘s extension

* Polish #4541 : Bugfix

* Polish #4541 : Optimization

* Polish #4541 : Add the compatibility for PollingWatchService on the some platforms

* Polish #4541 : Add delay publish without ThreadPoolExecutor

* Polish #4541 : Refactor the extension name

* Polish #4541 : Add remove ops

* Polish #4541 : Add testable constructor

* Polish #4541 : Add getConfigGroups method

* Polish #4610 : [Refactor] Refactor the bootstrap module

* Polish #4541 : Fix the nulling URL issue

* Polish #4622 : [Refactor] Refactor ConfigManager

* Polish #4622 : [Refactor] Refactor ConfigManager

* Polish #4622 : Support multiple configcenters

* Polish #4671 : ServiceNameMapping will not map the group, version and protocol

* update referenceCount log (#4683)

Add comments to support multiple shared connections

* Polish /#4687 : Remove the duplicated test code in dubbo-config-spring (#4688)

* #4685  修改代码if判断false问题 if (hasException == false)修改成if (!hasException) (#4695)

* Fixed Service annotation method parameters are not in effect (#4598)

* keep demo simple, and switch to use zookeeper as registry center (#4705)

* keep demo simple, and switch to use zookeeper as registry center

* remove comment

* @reference auto-wires the instance of generic interface #4594 (#4677)

* try to shorten maven output to make travis build pass (#4710)

* use CountDownLatch to check zk registry if establish connection (#4589)

* Minor change

* Rename the extension name of WritableMetadataService

* Polish #4759 : [Refactor] Change the signature of methods of MetadataService #4759

* Merge remote-tracking branch 'upstream/master' into dubbo-cloud-native

# Conflicts:
#	dubbo-all/pom.xml
#	dubbo-bom/pom.xml
#	dubbo-config/dubbo-config-api/src/main/java/org/apache/dubbo/config/AbstractInterfaceConfig.java
#	dubbo-config/dubbo-config-api/src/main/java/org/apache/dubbo/config/ApplicationConfig.java
#	dubbo-config/dubbo-config-api/src/main/java/org/apache/dubbo/config/ConfigCenterConfig.java
#	dubbo-config/dubbo-config-api/src/main/java/org/apache/dubbo/config/ReferenceConfig.java
#	dubbo-config/dubbo-config-api/src/main/java/org/apache/dubbo/config/RegistryConfig.java
#	dubbo-config/dubbo-config-api/src/main/java/org/apache/dubbo/config/ServiceConfig.java
#	dubbo-config/dubbo-config-api/src/test/java/org/apache/dubbo/config/ReferenceConfigTest.java
#	dubbo-configcenter/dubbo-configcenter-api/src/main/java/org/apache/dubbo/configcenter/DynamicConfiguration.java
#	dubbo-configcenter/dubbo-configcenter-api/src/test/java/org/apache/dubbo/configcenter/mock/MockDynamicConfiguration.java
#	dubbo-configcenter/dubbo-configcenter-consul/src/main/java/org/apache/dubbo/configcenter/consul/ConsulDynamicConfiguration.java
#	dubbo-configcenter/dubbo-configcenter-etcd/src/test/java/org/apache/dubbo/configcenter/support/etcd/EtcdDynamicConfigurationTest.java
#	dubbo-configcenter/dubbo-configcenter-nacos/src/main/java/org/apache/dubbo/configcenter/support/nacos/NacosDynamicConfiguration.java
#	dubbo-configcenter/dubbo-configcenter-nacos/src/test/java/org/apache/dubbo/configcenter/support/nacos/NacosDynamicConfigurationTest.java
#	dubbo-configcenter/dubbo-configcenter-zookeeper/src/main/java/org/apache/dubbo/configcenter/support/zookeeper/ZookeeperDynamicConfiguration.java
#	dubbo-metadata/dubbo-metadata-api/src/main/java/org/apache/dubbo/metadata/definition/model/MethodDefinition.java
#	dubbo-metadata/dubbo-metadata-api/src/main/java/org/apache/dubbo/metadata/report/identifier/MetadataIdentifier.java
#	dubbo-metadata/dubbo-metadata-api/src/main/java/org/apache/dubbo/metadata/report/support/AbstractMetadataReport.java
#	dubbo-metadata/dubbo-metadata-api/src/test/java/org/apache/dubbo/metadata/report/identifier/MetadataIdentifierTest.java
#	dubbo-metadata/dubbo-metadata-definition-protobuf/src/main/java/org/apache/dubbo/metadata/definition/protobuf/ProtobufTypeBuilder.java
#	dubbo-metadata/dubbo-metadata-definition-protobuf/src/test/java/org/apache/dubbo/metadata/definition/protobuf/ProtobufTypeBuilderTest.java
#	dubbo-metadata/pom.xml
#	dubbo-registry/dubbo-registry-api/src/main/java/org/apache/dubbo/registry/integration/AbstractConfiguratorListener.java
#	dubbo-registry/dubbo-registry-nacos/src/main/java/org/apache/dubbo/registry/nacos/NacosRegistry.java
#	dubbo-registry/dubbo-registry-nacos/src/main/java/org/apache/dubbo/registry/nacos/NacosRegistryFactory.java
#	dubbo-rpc/dubbo-rpc-xml/src/main/java/org/apache/dubbo/xml/rpc/protocol/xmlrpc/XmlRpcProtocol.java

* Polish #3984 : Add the implementation of Page<ServiceInstance> getInstances(String serviceName, int offset, int pageSize, boolean healthyOnly)

* Code merge

* Fix the cases

* Merge remote-tracking branch 'upstream/cloud-native' into dubbo-cloud-native

# Conflicts:
#	dubbo-bootstrap/src/test/java/org/apache/dubbo/bootstrap/DubboServiceProviderBootstrap.java
#	dubbo-metadata/dubbo-metadata-definition-protobuf/pom.xml
#	dubbo-registry/dubbo-registry-api/src/test/java/org/apache/dubbo/registry/support/ServiceOrientedRegistryTest.java
#	dubbo-registry/dubbo-registry-consul/src/main/java/org/apache/dubbo/registry/consul/ConsulServiceDiscoveryFactory.java
#	dubbo-registry/dubbo-registry-etcd3/src/main/java/org/apache/dubbo/registry/etcd/EtcdServiceDiscovery.java

* Refactor ConfigManager

* Refactor ConfigManager

* Resolve the issues on ConfigManager

* Refactor and add test-cases for ConfigManager

* Polish #4774 : [Feature] Dubbo Cloud Native - To Support in Spring

* Polish #4808 : [Feature] Add the registered/unregistered event mechanism ShutdownHook

* Polish #4807 : [Feature] Add the callback mechanism ShutdownHook #4807

* Polish #4813 : [Feature] add Prioritized implementation for ServiceInstanceCustomizer

* Polish #4815 : [Feature] Add the ServiceLoader for Dubbo's services or components

* Polish #4815 : [Feature] Add the ServiceLoader for Dubbo's services or components

* Polish #4813 : [Feature] add Prioritized implementation for ServiceInstanceCustomizer

* Polish #4807 : Add sort implementation

* Refactor

* Refactor

* Polish #4845 : [Feature] Enhance the Event-Publishing feature to original ServiceDiscovery

* Merge remote-tracking branch 'upstream/cloud-native' into dubbo-cloud-native

# Conflicts:
#	dubbo-registry/dubbo-registry-api/src/main/java/org/apache/dubbo/registry/client/DefaultServiceDiscoveryFactory.java
#	dubbo-registry/dubbo-registry-api/src/main/java/org/apache/dubbo/registry/client/ServiceDiscoveryRegistry.java

* Merge remote-tracking branch 'upstream/cloud-native' into dubbo-cloud-native

# Conflicts:
#	dubbo-registry/dubbo-registry-api/src/main/java/org/apache/dubbo/registry/client/DefaultServiceDiscoveryFactory.java
#	dubbo-registry/dubbo-registry-api/src/main/java/org/apache/dubbo/registry/client/ServiceDiscoveryRegistry.java

* Polish #4854 : [Feature] MetadataService supports the Dubbo protocol under auto-increased port

* Polish #4857 : [Enhancement] Sync the Metadata storage type into ApplicationConfig

* Polish #4868 : [Enhancement] Refactor ConfigChangeEvent

* Polish #4868 : [Enhancement] Refactor ConfigChangeEvent

* Polish #4873 : [Feature] Add a conditional EventListener into Event Module

* Polish #4875 : [Feature] Refactor ServiceInstancesChangedListener

* Remove the cycle dependencies

* Remove the cycle dependencies

* Polish #4903 : [Feature] Set source into the BeanDefinition of Dubbo Config

* Polish #4902 : [Feature] Dubbo Cloud Native to Spring XML scenario

* Polish #4713 : Initial the new module and dependencies

* Polish #4690 : AnnotatedBeanDefinitionRegistryUtils#registerBeans can't remove the duplicated bean definitions

* Polish #4690 : AnnotatedBeanDefinitionRegistryUtils#registerBeans can't remove the duplicated bean definitions

* Polish #4690 : AnnotatedBeanDefinitionRegistryUtils#registerBeans can't remove the duplicated bean definitions

* Polish #4910 : [Feature] To suppoort DubboLifecycleComponentApplicationListener in Spring XML scenario

* Polish #4713 : Add Service discovery implementation for Eureka #4713

* Polish #4713 : Add Service registration and discovery implementation for Eureka

* Polish #4713 : Add Service registration and discovery implementation for Eureka

* Polish #4920 : [Refactor] Extract the common implementation for URLs' revision

* Refactor

* Polish #4925 : ServiceDiscovery limits only one ServiceInstancesChangedListener each service

* Polish #4925 : ServiceDiscovery limits only one ServiceInstancesChangedListener each service

* Remove useless classes

* Bugfix & Refactor ServiceDiscoveryRegistry

* Polish #4937 : The calculation of Revision should add the parameters of URL

* Polish #4940 : NacosDynamicConfiguration supports getConfigKeys method

* Polish #4942 : Dubbo Cloud Native supports multiple protcols

* Polish #4944 : [Feature] Simplify The metadata of URL for MetadataService

* Polish #4947 : [Feature] Dubbo Cloud-Native supports the REST call to Non-Dubbo

dubbo-bootstrap/src/test/java/org/apache/dubbo/bootstrap/NacosDubboServiceConsumerBootstrap.java

@@ -35,26 +35,21 @@ public static void main(String[] args) throws Exception {
 //        applicationConfig.setMetadataType("remote");
         new DubboBootstrap()
                 .application(applicationConfig)
-                // Zookeeper
-                .registry("nacos", builder -> builder.address("nacos://127.0.0.1:8848?registry-type=service&subscribed-services=dubbo-nacos-provider-demo"))
+                .registry("nacos", builder -> builder.address("nacos://127.0.0.1:8848?registry-type=service&subscribed-services=service-provider"))
                 .metadataReport(new MetadataReportConfig("nacos://127.0.0.1:8848"))
-                // Nacos
-//                .registry("consul", builder -> builder.address("consul://127.0.0.1:8500?registry.type=service&subscribed.services=dubbo-provider-demo").group("namespace1"))
-                .reference("echo", builder -> builder.interfaceClass(EchoService.class).protocol("dubbo"))
                 .reference("user", builder -> builder.interfaceClass(UserService.class).protocol("rest"))
                 .start()
                 .await();
 
         ConfigManager configManager = ConfigManager.getInstance();
 
-        ReferenceConfig<EchoService> referenceConfig = configManager.getReference("echo");
+        ReferenceConfig<UserService> referenceConfig = configManager.getReference("user");
 
-        EchoService echoService = referenceConfig.get();
+        UserService userService = referenceConfig.get();
 
         for (int i = 0; i < 500; i++) {
             Thread.sleep(2000L);
-            System.out.println(echoService.echo("Hello,World"));
+            System.out.println(userService.getUser(i * 1L));
         }
-
     }
 }

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

@@ -31,12 +31,14 @@
 import org.apache.dubbo.registry.client.event.ServiceInstancesChangedEvent;
 import org.apache.dubbo.registry.client.event.listener.ServiceInstancesChangedListener;
 import org.apache.dubbo.registry.client.metadata.ServiceInstanceMetadataUtils;
+import org.apache.dubbo.registry.client.metadata.SubscribedURLsSynthesizer;
 import org.apache.dubbo.registry.client.metadata.proxy.MetadataServiceProxyFactory;
 import org.apache.dubbo.registry.client.selector.ServiceInstanceSelector;
 import org.apache.dubbo.registry.support.FailbackRegistry;
 
 import java.util.ArrayList;
 import java.util.Collection;
+import java.util.Collections;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.LinkedHashMap;
@@ -72,6 +74,7 @@
 import static org.apache.dubbo.common.function.ThrowableAction.execute;
 import static org.apache.dubbo.common.utils.CollectionUtils.isEmpty;
 import static org.apache.dubbo.common.utils.CollectionUtils.isNotEmpty;
+import static org.apache.dubbo.common.utils.DubboServiceLoader.loadServices;
 import static org.apache.dubbo.common.utils.StringUtils.isBlank;
 import static org.apache.dubbo.metadata.WritableMetadataService.DEFAULT_EXTENSION;
 import static org.apache.dubbo.registry.client.ServiceDiscoveryFactory.getExtension;
@@ -110,6 +113,8 @@ public class ServiceDiscoveryRegistry extends FailbackRegistry {
 
     private final Set<String> registeredListeners = new LinkedHashSet<>();
 
+    private final List<SubscribedURLsSynthesizer> subscribedURLsSynthesizers;
+
     /**
      * A cache for all URLs of services that the subscribed services exported
      * The key is the service name
@@ -124,6 +129,7 @@ public ServiceDiscoveryRegistry(URL registryURL) {
         this.serviceNameMapping = ServiceNameMapping.getDefaultExtension();
         String metadataStorageType = getMetadataStorageType(registryURL);
         this.writableMetadataService = WritableMetadataService.getExtension(metadataStorageType);
+        this.subscribedURLsSynthesizers = initSubscribedURLsSynthesizers();
     }
 
     /**
@@ -157,6 +163,10 @@ protected ServiceDiscovery createServiceDiscovery(URL registryURL) {
         return serviceDiscovery;
     }
 
+    private List<SubscribedURLsSynthesizer> initSubscribedURLsSynthesizers() {
+        return loadServices(SubscribedURLsSynthesizer.class, this.getClass().getClassLoader());
+    }
+
     /**
      * Get the instance {@link ServiceDiscovery} from the registry {@link URL} using
      * {@link ServiceDiscoveryFactory} SPI
@@ -331,12 +341,32 @@ protected void subscribeURLs(URL subscribedURL, NotifyListener listener, String
             return;
         }
 
-        List<URL> subscribedURLs = getSubscribedURLs(subscribedURL, serviceInstances);
+        List<URL> subscribedURLs = new LinkedList<>();
+
+        /**
+         * Add the exported URLs from {@link MetadataService}
+         */
+        subscribedURLs.addAll(getExportedURLs(subscribedURL, serviceInstances));
+
+        if (subscribedURLs.isEmpty()) { // If empty, try to synthesize
+            /**
+             * Add the subscribed URLs that were synthesized
+             */
+            subscribedURLs.addAll(synthesizeSubscribedURLs(subscribedURL, serviceInstances));
+        }
 
         listener.notify(subscribedURLs);
     }
 
-    private List<URL> getSubscribedURLs(URL subscribedURL, Collection<ServiceInstance> instances) {
+    /**
+     * Get the exported {@link URL URLs} from the  {@link MetadataService} in the specified
+     * {@link ServiceInstance service instances}
+     *
+     * @param subscribedURL the subscribed {@link URL url}
+     * @param instances     {@link ServiceInstance service instances}
+     * @return the exported {@link URL URLs} if present, or <code>{@link Collections#emptyList() empty list}</code>
+     */
+    private List<URL> getExportedURLs(URL subscribedURL, Collection<ServiceInstance> instances) {
 
         // local service instances could be mutable
         List<ServiceInstance> serviceInstances = instances.stream()
@@ -356,7 +386,7 @@ private List<URL> getSubscribedURLs(URL subscribedURL, Collection<ServiceInstanc
         initTemplateURLs(subscribedURL, serviceInstances);
 
         // Clone the subscribed URLs from the template URLs
-        List<URL> subscribedURLs = cloneSubscribedURLs(subscribedURL, serviceInstances);
+        List<URL> subscribedURLs = cloneExportedURLs(subscribedURL, serviceInstances);
         // clear local service instances
         serviceInstances.clear();
         return subscribedURLs;
@@ -368,7 +398,7 @@ private void initTemplateURLs(URL subscribedURL, List<ServiceInstance> serviceIn
             // select a instance of {@link ServiceInstance}
             ServiceInstance selectedInstance = selectServiceInstance(serviceInstances);
             // try to get the template URLs
-            List<URL> templateURLs = getTemplateURLs(subscribedURL, selectedInstance);
+            List<URL> templateURLs = getTemplateExportedURLs(subscribedURL, selectedInstance);
             if (isNotEmpty(templateURLs)) { // If the result is valid
                 break; // break the loop
             } else {
@@ -407,19 +437,19 @@ private void expungeStaleRevisionExportedURLs(List<ServiceInstance> serviceInsta
         }
     }
 
-    private List<URL> cloneSubscribedURLs(URL subscribedURL, Collection<ServiceInstance> serviceInstances) {
+    private List<URL> cloneExportedURLs(URL subscribedURL, Collection<ServiceInstance> serviceInstances) {
 
         if (isEmpty(serviceInstances)) {
             return emptyList();
         }
 
-        List<URL> clonedURLs = new LinkedList<>();
+        List<URL> clonedExportedURLs = new LinkedList<>();
 
         serviceInstances.forEach(serviceInstance -> {
 
             String host = serviceInstance.getHost();
 
-            getTemplateURLs(subscribedURL, serviceInstance)
+            getTemplateExportedURLs(subscribedURL, serviceInstance)
                     .stream()
                     .map(templateURL -> templateURL.removeParameter(TIMESTAMP_KEY))
                     .map(templateURL -> templateURL.removeParameter(PID_KEY))
@@ -437,9 +467,9 @@ private List<URL> cloneSubscribedURLs(URL subscribedURL, Collection<ServiceInsta
 
                         return clonedURLBuilder.build();
                     })
-                    .forEach(clonedURLs::add);
+                    .forEach(clonedExportedURLs::add);
         });
-        return clonedURLs;
+        return clonedExportedURLs;
     }
 
 
@@ -461,7 +491,7 @@ private ServiceInstance selectServiceInstance(List<ServiceInstance> serviceInsta
     }
 
     /**
-     * Get the template {@link URL urls} from the specified {@link ServiceInstance}.
+     * Get the template exported {@link URL urls} from the specified {@link ServiceInstance}.
      * <p>
      * First, put the revision {@link ServiceInstance service instance}
      * associating {@link #getExportedURLs(URL, ServiceInstance) exported URLs} into cache.
@@ -478,7 +508,7 @@ private ServiceInstance selectServiceInstance(List<ServiceInstance> serviceInsta
      *                         associating with the {@link URL urls}
      * @return non-null {@link List} of {@link URL urls}
      */
-    protected List<URL> getTemplateURLs(URL subscribedURL, ServiceInstance selectedInstance) {
+    private List<URL> getTemplateExportedURLs(URL subscribedURL, ServiceInstance selectedInstance) {
 
         List<URL> exportedURLs = getRevisionExportedURLs(selectedInstance);
 
@@ -655,6 +685,21 @@ protected List<URL> getExportedURLs(URL subscribedURL, ServiceInstance providerS
         return exportedURLs;
     }
 
+    /**
+     * Synthesize new subscribed {@link URL URLs} from old one
+     *
+     * @param subscribedURL
+     * @param serviceInstances
+     * @return non-null
+     */
+    private Collection<? extends URL> synthesizeSubscribedURLs(URL subscribedURL, Collection<ServiceInstance> serviceInstances) {
+        return subscribedURLsSynthesizers.stream()
+                .filter(synthesizer -> synthesizer.supports(subscribedURL))
+                .map(synthesizer -> synthesizer.synthesize(subscribedURL, serviceInstances))
+                .flatMap(Collection::stream)
+                .collect(Collectors.toList());
+    }
+
 
     protected Set<String> getServices(URL subscribedURL) {
         Set<String> serviceNames = getSubscribedServices();

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

@@ -0,0 +1,91 @@
+/*
+ * 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.client.metadata;
+
+import org.apache.dubbo.common.URL;
+import org.apache.dubbo.common.URLBuilder;
+import org.apache.dubbo.common.utils.StringUtils;
+import org.apache.dubbo.registry.client.ServiceInstance;
+import org.apache.dubbo.rpc.Protocol;
+
+import java.util.Collection;
+import java.util.List;
+import java.util.Map;
+import java.util.stream.Collectors;
+
+import static java.lang.Boolean.TRUE;
+import static org.apache.dubbo.common.constants.CommonConstants.PID_KEY;
+import static org.apache.dubbo.common.constants.CommonConstants.PROTOCOL_KEY;
+import static org.apache.dubbo.common.constants.CommonConstants.PROVIDER;
+import static org.apache.dubbo.common.constants.CommonConstants.SIDE_KEY;
+import static org.apache.dubbo.common.constants.CommonConstants.TIMESTAMP_KEY;
+import static org.apache.dubbo.common.constants.RegistryConstants.CATEGORY_KEY;
+import static org.apache.dubbo.registry.Constants.REGISTER_KEY;
+import static org.apache.dubbo.rpc.Constants.LAZY_CONNECT_KEY;
+import static org.apache.dubbo.rpc.cluster.Constants.CLUSTER_STICKY_KEY;
+
+/**
+ * {@link SubscribedURLsSynthesizer} implementation for REST {@link Protocol protocol}
+ *
+ * @since 2.7.4
+ */
+public class RestProtocolSubscribedURLsSynthesizer implements SubscribedURLsSynthesizer {
+
+    @Override
+    public boolean supports(URL subscribedURL) {
+        return "rest".equals(subscribedURL.getProtocol()) ||
+                "rest".equals(subscribedURL.getParameter(PROTOCOL_KEY));
+    }
+
+    @Override
+    public List<URL> synthesize(URL subscribedURL, Collection<ServiceInstance> serviceInstances) {
+
+        String protocol = subscribedURL.getParameter(PROTOCOL_KEY);
+
+        Map<String, String> parametersToCopy = subscribedURL.removeParameter(CATEGORY_KEY)
+                .removeParameter(PROTOCOL_KEY)
+                .removeParameter(SIDE_KEY)
+                .removeParameter(CLUSTER_STICKY_KEY)
+                .removeParameter(TIMESTAMP_KEY)
+                .removeParameter(PID_KEY)
+                .removeParameter(LAZY_CONNECT_KEY)
+                .getParameters();
+
+        return serviceInstances.stream().map(serviceInstance -> {
+            URLBuilder urlBuilder = new URLBuilder()
+                    .setProtocol(protocol)
+                    .setHost(serviceInstance.getHost())
+                    .setPort(serviceInstance.getPort())
+                    .setPath(subscribedURL.getServiceInterface())
+                    .addParameter(SIDE_KEY, PROVIDER)
+                    .addParameter(REGISTER_KEY, TRUE.toString());
+
+            // Copy the parameters
+            parametersToCopy.forEach((key, value) -> {
+                urlBuilder.addParameter(key, value);
+            });
+
+            return urlBuilder.build();
+        }).collect(Collectors.toList());
+    }
+
+    private void addParameter(URLBuilder urlBuilder, String key, String value) {
+        if (StringUtils.isNotEmpty(value)) {
+            urlBuilder.addParameter(key, value);
+        }
+    }
+}

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

@@ -0,0 +1,53 @@
+/*
+ * 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.client.metadata;
+
+import org.apache.dubbo.common.URL;
+import org.apache.dubbo.common.lang.Prioritized;
+import org.apache.dubbo.registry.NotifyListener;
+import org.apache.dubbo.registry.Registry;
+import org.apache.dubbo.registry.client.ServiceInstance;
+
+import java.util.Collection;
+import java.util.List;
+
+/**
+ * The inteface to synthesize the subscribed {@link URL URLs}
+ *
+ * @since 2.7.4
+ */
+public interface SubscribedURLsSynthesizer extends Prioritized {
+
+    /**
+     * Supports the synthesis of the subscribed {@link URL URLs} or not
+     *
+     * @param subscribedURL the original subscribed {@link URL} from the execution of`
+     *                      {@link Registry#subscribe(URL, NotifyListener)} method
+     * @return if supports, return <code>true</code>, or <code>false</code>
+     */
+    boolean supports(URL subscribedURL);
+
+    /**
+     * synthesize the subscribed {@link URL URLs}
+     *
+     * @param subscribedURL    the original subscribed {@link URL} from the execution of`
+     *                         {@link Registry#subscribe(URL, NotifyListener)} method
+     * @param serviceInstances
+     * @return
+     */
+    List<URL> synthesize(URL subscribedURL, Collection<ServiceInstance> serviceInstances);
+}

dubbo-registry/dubbo-registry-api/src/main/resources/META-INF/services/org.apache.dubbo.registry.client.metadata.SubscribedURLsSynthesizer

@@ -0,0 +1 @@
+org.apache.dubbo.registry.client.metadata.RestProtocolSubscribedURLsSynthesizer