Polish spring-cloud-incubator/spring-cloud-alibaba#376 : Dubbo Metadata Configuration replaces Nacos 's implementation

spring-cloud-alibaba-dubbo/src/main/java/org/springframework/cloud/alibaba/dubbo/autoconfigure/DubboMetadataAutoConfiguration.java

@@ -16,15 +16,22 @@
  */
 package org.springframework.cloud.alibaba.dubbo.autoconfigure;
 
-import org.springframework.boot.autoconfigure.condition.ConditionalOnBean;
+import com.alibaba.dubbo.config.ProtocolConfig;
+import com.alibaba.dubbo.config.spring.context.annotation.DubboComponentScan;
+
+import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
 import org.springframework.cloud.alibaba.dubbo.metadata.repository.DubboServiceMetadataRepository;
-import org.springframework.cloud.alibaba.dubbo.service.MetadataConfigService;
+import org.springframework.cloud.alibaba.dubbo.service.DubboGenericServiceFactory;
-import org.springframework.cloud.alibaba.dubbo.service.NacosMetadataConfigService;
+import org.springframework.cloud.alibaba.dubbo.service.DubboMetadataConfigServiceProxy;
-import org.springframework.cloud.alibaba.nacos.NacosConfigProperties;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.context.annotation.Import;
 
+import java.util.Collection;
+import java.util.Iterator;
+
+import static com.alibaba.dubbo.common.Constants.DEFAULT_PROTOCOL;
+
 /**
  * Spring Boot Auto-Configuration class for Dubbo Metadata
  *
@@ -32,12 +39,39 @@ import org.springframework.context.annotation.Import;
  */
 @Configuration
 @Import(DubboServiceMetadataRepository.class)
+@DubboComponentScan(basePackages = "org.springframework.cloud.alibaba.dubbo.service")
 public class DubboMetadataAutoConfiguration {
 
-    @Bean
+    public static final String METADATA_PROTOCOL_BEAN_NAME = "metadata";
-    @ConditionalOnBean(NacosConfigProperties.class)
+
-    public MetadataConfigService metadataConfigService() {
+    /**
-        return new NacosMetadataConfigService();
+     * Build an alias Bean for {@link ProtocolConfig}
+     *
+     * @param protocols {@link ProtocolConfig} Beans
+     * @return {@link ProtocolConfig} bean
+     */
+    @Bean(name = METADATA_PROTOCOL_BEAN_NAME)
+    public ProtocolConfig protocolConfig(Collection<ProtocolConfig> protocols) {
+        ProtocolConfig protocolConfig = null;
+        for (ProtocolConfig protocol : protocols) {
+            String protocolName = protocol.getName();
+            if (DEFAULT_PROTOCOL.equals(protocolName)) {
+                protocolConfig = protocol;
+                break;
+            }
         }
 
+        if (protocolConfig == null) { // If The ProtocolConfig bean named "dubbo" is absent, take first one of them
+            Iterator<ProtocolConfig> iterator = protocols.iterator();
+            protocolConfig = iterator.hasNext() ? iterator.next() : null;
+        }
+
+        return protocolConfig;
+    }
+
+    @Bean
+    @ConditionalOnMissingBean
+    public DubboMetadataConfigServiceProxy dubboMetadataConfigServiceProxy(DubboGenericServiceFactory factory) {
+        return new DubboMetadataConfigServiceProxy(factory);
+    }
 }

spring-cloud-alibaba-dubbo/src/main/java/org/springframework/cloud/alibaba/dubbo/autoconfigure/DubboRestMetadataRegistrationAutoConfiguration.java

@@ -24,17 +24,12 @@ import org.springframework.beans.factory.annotation.Value;
 import org.springframework.boot.autoconfigure.AutoConfigureAfter;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnBean;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
-import org.springframework.boot.context.event.ApplicationStartedEvent;
-import org.springframework.cloud.alibaba.dubbo.metadata.ServiceRestMetadata;
 import org.springframework.cloud.alibaba.dubbo.metadata.resolver.MetadataResolver;
-import org.springframework.cloud.alibaba.dubbo.service.MetadataConfigService;
+import org.springframework.cloud.alibaba.dubbo.service.PublishingDubboMetadataConfigService;
 import org.springframework.cloud.client.serviceregistry.Registration;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.context.event.EventListener;
 
-import java.util.LinkedHashSet;
-import java.util.Set;
-
 /**
  * The Auto-Configuration class for Dubbo REST metadata registration,
  * REST metadata that is a part of {@link Registration#getMetadata() Spring Cloud service instances' metadata}
@@ -44,24 +39,17 @@ import java.util.Set;
  */
 @ConditionalOnProperty(value = "spring.cloud.service-registry.auto-registration.enabled", matchIfMissing = true)
 @ConditionalOnBean(value = {
-        MetadataResolver.class,
+        MetadataResolver.class
-        MetadataConfigService.class
 })
 @AutoConfigureAfter(value = {DubboMetadataAutoConfiguration.class})
 @Configuration
 public class DubboRestMetadataRegistrationAutoConfiguration {
 
-    /**
-     * A Map to store REST metadata temporary, its' key is the special service name for a Dubbo service,
-     * the value is a JSON content of JAX-RS or Spring MVC REST metadata from the annotated methods.
-     */
-    private final Set<ServiceRestMetadata> serviceRestMetadata = new LinkedHashSet<>();
-
     @Autowired
     private MetadataResolver metadataResolver;
 
     @Autowired
-    private MetadataConfigService metadataConfigService;
+    private PublishingDubboMetadataConfigService dubboMetadataConfigService;
 
     @Value("${spring.application.name:application}")
     private String currentApplicationName;
@@ -69,15 +57,6 @@ public class DubboRestMetadataRegistrationAutoConfiguration {
     @EventListener(ServiceBeanExportedEvent.class)
     public void recordRestMetadata(ServiceBeanExportedEvent event) {
         ServiceBean serviceBean = event.getServiceBean();
-        serviceRestMetadata.addAll(metadataResolver.resolveServiceRestMetadata(serviceBean));
+        dubboMetadataConfigService.publishServiceRestMetadata(metadataResolver.resolveServiceRestMetadata(serviceBean));
-    }
-
-    /**
-     * Publish <code>serviceRestMetadata</code> with the JSON format into
-     * {@link Registration#getMetadata() service instances' metadata} when The Spring Application is started.
-     */
-    @EventListener(ApplicationStartedEvent.class)
-    public void registerRestMetadata() {
-        metadataConfigService.publishServiceRestMetadata(currentApplicationName, serviceRestMetadata);
     }
 }

spring-cloud-alibaba-dubbo/src/main/java/org/springframework/cloud/alibaba/dubbo/metadata/repository/DubboServiceMetadataRepository.java

@@ -16,6 +16,8 @@
  */
 package org.springframework.cloud.alibaba.dubbo.metadata.repository;
 
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.type.TypeFactory;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.springframework.beans.factory.annotation.Autowired;
@@ -23,11 +25,14 @@ import org.springframework.cloud.alibaba.dubbo.http.matcher.RequestMetadataMatch
 import org.springframework.cloud.alibaba.dubbo.metadata.DubboServiceMetadata;
 import org.springframework.cloud.alibaba.dubbo.metadata.RequestMetadata;
 import org.springframework.cloud.alibaba.dubbo.metadata.ServiceRestMetadata;
-import org.springframework.cloud.alibaba.dubbo.service.MetadataConfigService;
+import org.springframework.cloud.alibaba.dubbo.service.DubboMetadataConfigService;
+import org.springframework.cloud.alibaba.dubbo.service.DubboMetadataConfigServiceProxy;
 import org.springframework.http.HttpRequest;
 import org.springframework.stereotype.Repository;
 
+import java.util.Collections;
 import java.util.LinkedHashMap;
+import java.util.LinkedHashSet;
 import java.util.Map;
 import java.util.Set;
 
@@ -44,6 +49,8 @@ public class DubboServiceMetadataRepository {
 
     private final Logger logger = LoggerFactory.getLogger(getClass());
 
+    private final ObjectMapper objectMapper = new ObjectMapper();
+
     /**
      * Key is application name
      * Value is  Map<RequestMetadata, DubboServiceMetadata>
@@ -51,7 +58,7 @@ public class DubboServiceMetadataRepository {
     private Map<String, Map<RequestMetadataMatcher, DubboServiceMetadata>> repository = newHashMap();
 
     @Autowired
-    private MetadataConfigService metadataConfigService;
+    private DubboMetadataConfigServiceProxy dubboMetadataConfigServiceProxy;
 
     /**
      * Initialize the specified service's Dubbo Service Metadata
@@ -64,7 +71,7 @@ public class DubboServiceMetadataRepository {
             return;
         }
 
-        Set<ServiceRestMetadata> serviceRestMetadataSet = metadataConfigService.getServiceRestMetadata(serviceName);
+        Set<ServiceRestMetadata> serviceRestMetadataSet = getServiceRestMetadataSet(serviceName);
 
         if (isEmpty(serviceRestMetadataSet)) {
             if (logger.isWarnEnabled()) {
@@ -145,6 +152,23 @@ public class DubboServiceMetadataRepository {
         return getMap(repository, serviceName);
     }
 
+    private Set<ServiceRestMetadata> getServiceRestMetadataSet(String serviceName) {
+        DubboMetadataConfigService dubboMetadataConfigService = dubboMetadataConfigServiceProxy.newProxy(serviceName);
+        String serviceRestMetadataJsonConfig = dubboMetadataConfigService.getServiceRestMetadata();
+
+        Set<ServiceRestMetadata> metadata;
+        try {
+            metadata = objectMapper.readValue(serviceRestMetadataJsonConfig,
+                    TypeFactory.defaultInstance().constructCollectionType(LinkedHashSet.class, ServiceRestMetadata.class));
+        } catch (Exception e) {
+            if (logger.isErrorEnabled()) {
+                logger.error(e.getMessage(), e);
+            }
+            metadata = Collections.emptySet();
+        }
+        return metadata;
+    }
+
     private static <K, V> Map<K, V> getMap(Map<String, Map<K, V>> repository, String key) {
         return getOrDefault(repository, key, newHashMap());
     }
@@ -161,4 +185,5 @@ public class DubboServiceMetadataRepository {
     private static <K, V> Map<K, V> newHashMap() {
         return new LinkedHashMap<>();
     }
+
 }

spring-cloud-alibaba-dubbo/src/main/java/org/springframework/cloud/alibaba/dubbo/metadata/resolver/DubboServiceBeanMetadataResolver.java

@@ -127,12 +127,22 @@ public class DubboServiceBeanMetadataResolver implements BeanClassLoaderAware, S
     public Set<RestMethodMetadata> resolveMethodRestMetadata(Class<?> targetType) {
         List<Method> feignContractMethods = selectFeignContractMethods(targetType);
         return contracts.stream()
-                .map(contract -> contract.parseAndValidatateMetadata(targetType))
+                .map(contract -> parseAndValidateMetadata(contract, targetType))
                 .flatMap(v -> v.stream())
                 .map(methodMetadata -> resolveMethodRestMetadata(methodMetadata, targetType, feignContractMethods))
                 .collect(Collectors.toSet());
     }
 
+    private List<MethodMetadata> parseAndValidateMetadata(Contract contract, Class<?> targetType) {
+        List<MethodMetadata> methodMetadataList = Collections.emptyList();
+        try {
+            methodMetadataList = contract.parseAndValidatateMetadata(targetType);
+        } catch (Throwable ignored) {
+            // ignore
+        }
+        return methodMetadataList;
+    }
+
     /**
      * Select feign contract methods
      * <p>

spring-cloud-alibaba-dubbo/src/main/java/org/springframework/cloud/alibaba/dubbo/service/DubboGenericServiceFactory.java

@@ -50,18 +50,18 @@ public class DubboGenericServiceFactory {
     public GenericService create(DubboServiceMetadata dubboServiceMetadata,
                                  DubboTransportedMetadata dubboTransportedMetadata) {
 
-        Integer key = Objects.hash(dubboServiceMetadata, dubboTransportedMetadata);
+        ReferenceBean<GenericService> referenceBean = build(dubboServiceMetadata.getServiceRestMetadata(), dubboTransportedMetadata);
-
-        ReferenceBean<GenericService> referenceBean = cache.get(key);
-
-        if (referenceBean == null) {
-            referenceBean = build(dubboServiceMetadata.getServiceRestMetadata(), dubboTransportedMetadata);
-            cache.putIfAbsent(key, referenceBean);
-        }
 
         return referenceBean == null ? null : referenceBean.get();
     }
 
+    public GenericService create(String serviceName, Class<?> serviceClass) {
+        String interfaceName = serviceClass.getName();
+        ReferenceBean<GenericService> referenceBean = build(interfaceName, serviceName, null,
+                "dubbo", "failover");
+        return referenceBean.get();
+    }
+
 
     private ReferenceBean<GenericService> build(ServiceRestMetadata serviceRestMetadata,
                                                 DubboTransportedMetadata dubboTransportedMetadata) {
@@ -70,14 +70,28 @@ public class DubboGenericServiceFactory {
         String interfaceName = getServiceInterface(segments);
         String version = getServiceVersion(segments);
         String group = getServiceGroup(segments);
+        String protocol = dubboTransportedMetadata.getProtocol();
+        String cluster = dubboTransportedMetadata.getCluster();
 
-        ReferenceBean<GenericService> referenceBean = new ReferenceBean<GenericService>();
+        return build(interfaceName, version, group, protocol, cluster);
+    }
+
+    private ReferenceBean<GenericService> build(String interfaceName, String version, String group, String protocol,
+                                                String cluster) {
+
+        Integer key = Objects.hash(interfaceName, version, group, protocol, cluster);
+
+        ReferenceBean<GenericService> referenceBean = cache.get(key);
+
+        if (referenceBean == null) {
+            referenceBean = new ReferenceBean<>();
             referenceBean.setGeneric(true);
             referenceBean.setInterface(interfaceName);
             referenceBean.setVersion(version);
             referenceBean.setGroup(group);
-        referenceBean.setProtocol(dubboTransportedMetadata.getProtocol());
+            referenceBean.setProtocol(protocol);
-        referenceBean.setCluster(dubboTransportedMetadata.getCluster());
+            referenceBean.setCluster(cluster);
+        }
 
         return referenceBean;
     }

spring-cloud-alibaba-dubbo/src/main/java/org/springframework/cloud/alibaba/dubbo/service/DubboMetadataConfigService.java

@@ -21,13 +21,16 @@ import org.springframework.cloud.alibaba.dubbo.metadata.ServiceRestMetadata;
 import java.util.Set;
 
 /**
- * Config Service for Metadata
+ * Dubbo Metadata Configuration Service
  *
  * @author <a href="mailto:mercyblitz@gmail.com">Mercy</a>
  */
-public interface MetadataConfigService {
+public interface DubboMetadataConfigService {
 
-    void publishServiceRestMetadata(String serviceName, Set<ServiceRestMetadata> serviceRestMetadata);
+    /**
-
+     * Get The json content of {@link ServiceRestMetadata} {@link Set}
-    Set<ServiceRestMetadata> getServiceRestMetadata(String serviceName);
+     *
+     * @return the non-null String
+     */
+    String getServiceRestMetadata();
 }

spring-cloud-alibaba-dubbo/src/main/java/org/springframework/cloud/alibaba/dubbo/service/DubboMetadataConfigServiceInvocationHandler.java

@@ -0,0 +1,54 @@
+/*
+ * 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.springframework.cloud.alibaba.dubbo.service;
+
+import com.alibaba.dubbo.rpc.service.GenericService;
+
+import java.lang.reflect.InvocationHandler;
+import java.lang.reflect.Method;
+
+/**
+ * {@link DubboMetadataConfigService} {@link InvocationHandler}
+ *
+ * @author <a href="mailto:mercyblitz@gmail.com">Mercy</a>
+ */
+class DubboMetadataConfigServiceInvocationHandler implements InvocationHandler {
+
+    /**
+     * The method name of {@link DubboMetadataConfigService#getServiceRestMetadata()}
+     */
+    private static final String METHOD_NAME = "getServiceRestMetadata";
+
+    private static final String[] PARAMETER_TYPES = new String[0];
+
+    private static final String[] PARAMETER_VALUES = new String[0];
+
+    private final GenericService genericService;
+
+    public DubboMetadataConfigServiceInvocationHandler(String serviceName, DubboGenericServiceFactory dubboGenericServiceFactory) {
+        this.genericService = dubboGenericServiceFactory.create(serviceName, DubboMetadataConfigService.class);
+    }
+
+    @Override
+    public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
+        String methodName = method.getName();
+        if (METHOD_NAME.equals(methodName)) {
+            return genericService.$invoke(methodName, PARAMETER_TYPES, PARAMETER_VALUES);
+        }
+        return method.invoke(proxy, args);
+    }
+}

spring-cloud-alibaba-dubbo/src/main/java/org/springframework/cloud/alibaba/dubbo/service/DubboMetadataConfigServiceProxy.java

@@ -0,0 +1,51 @@
+/*
+ * 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.springframework.cloud.alibaba.dubbo.service;
+
+import org.springframework.beans.factory.BeanClassLoaderAware;
+
+import static java.lang.reflect.Proxy.newProxyInstance;
+
+/**
+ * The proxy of {@link DubboMetadataConfigService}
+ */
+public class DubboMetadataConfigServiceProxy implements BeanClassLoaderAware {
+
+    private final DubboGenericServiceFactory dubboGenericServiceFactory;
+
+    private ClassLoader classLoader;
+
+    public DubboMetadataConfigServiceProxy(DubboGenericServiceFactory dubboGenericServiceFactory) {
+        this.dubboGenericServiceFactory = dubboGenericServiceFactory;
+    }
+
+    /**
+     * New proxy instance of {@link DubboMetadataConfigService} via the specified service name
+     *
+     * @param serviceName the service name
+     * @return a {@link DubboMetadataConfigService} proxy
+     */
+    public DubboMetadataConfigService newProxy(String serviceName) {
+        return (DubboMetadataConfigService) newProxyInstance(classLoader, new Class[]{DubboMetadataConfigService.class},
+                new DubboMetadataConfigServiceInvocationHandler(serviceName, dubboGenericServiceFactory));
+    }
+
+    @Override
+    public void setBeanClassLoader(ClassLoader classLoader) {
+        this.classLoader = classLoader;
+    }
+}

spring-cloud-alibaba-dubbo/src/main/java/org/springframework/cloud/alibaba/dubbo/service/NacosMetadataConfigService.java

@@ -1,98 +0,0 @@
-/*
- * 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.springframework.cloud.alibaba.dubbo.service;
-
-import com.alibaba.nacos.api.config.ConfigService;
-import com.alibaba.nacos.api.exception.NacosException;
-
-import com.fasterxml.jackson.core.JsonProcessingException;
-import com.fasterxml.jackson.databind.ObjectMapper;
-import com.fasterxml.jackson.databind.SerializationFeature;
-import com.fasterxml.jackson.databind.type.TypeFactory;
-import org.springframework.beans.factory.annotation.Autowired;
-import org.springframework.cloud.alibaba.dubbo.metadata.ServiceRestMetadata;
-import org.springframework.cloud.alibaba.nacos.NacosConfigProperties;
-
-import javax.annotation.PostConstruct;
-import java.util.Collections;
-import java.util.LinkedHashSet;
-import java.util.Set;
-
-import static com.alibaba.nacos.api.common.Constants.DEFAULT_GROUP;
-
-/**
- * Nacos {@link MetadataConfigService}
- *
- * @author <a href="mailto:mercyblitz@gmail.com">Mercy</a>
- */
-public class NacosMetadataConfigService implements MetadataConfigService {
-
-    private final ObjectMapper objectMapper = new ObjectMapper();
-
-    @Autowired
-    private NacosConfigProperties nacosConfigProperties;
-
-    private ConfigService configService;
-
-    @PostConstruct
-    public void init() {
-        this.configService = nacosConfigProperties.configServiceInstance();
-        this.objectMapper.enable(SerializationFeature.INDENT_OUTPUT);
-    }
-
-    /**
-     * Get the data Id of service rest metadata
-     */
-    private static String getServiceRestMetadataDataId(String serviceName) {
-        return "metadata:rest:" + serviceName + ".json";
-    }
-
-    @Override
-    public void publishServiceRestMetadata(String serviceName, Set<ServiceRestMetadata> serviceRestMetadata) {
-        String dataId = getServiceRestMetadataDataId(serviceName);
-        String json = writeValueAsString(serviceRestMetadata);
-        try {
-            configService.publishConfig(dataId, DEFAULT_GROUP, json);
-        } catch (NacosException e) {
-            throw new RuntimeException(e);
-        }
-    }
-
-    @Override
-    public Set<ServiceRestMetadata> getServiceRestMetadata(String serviceName) {
-        Set<ServiceRestMetadata> metadata = Collections.emptySet();
-        String dataId = getServiceRestMetadataDataId(serviceName);
-        try {
-            String json = configService.getConfig(dataId, DEFAULT_GROUP, 1000 * 3);
-            metadata = objectMapper.readValue(json,
-                    TypeFactory.defaultInstance().constructCollectionType(LinkedHashSet.class, ServiceRestMetadata.class));
-        } catch (Exception e) {
-            throw new RuntimeException(e);
-        }
-        return metadata;
-    }
-
-    private String writeValueAsString(Object object) {
-        String content = null;
-        try {
-            content = objectMapper.writeValueAsString(object);
-        } catch (JsonProcessingException e) {
-            throw new IllegalArgumentException(e);
-        }
-        return content;
-    }
-}

spring-cloud-alibaba-dubbo/src/main/java/org/springframework/cloud/alibaba/dubbo/service/PublishingDubboMetadataConfigService.java

@@ -0,0 +1,78 @@
+/*
+ * 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.springframework.cloud.alibaba.dubbo.service;
+
+import com.alibaba.dubbo.config.annotation.Service;
+
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.SerializationFeature;
+import org.springframework.cloud.alibaba.dubbo.metadata.ServiceRestMetadata;
+import org.springframework.util.CollectionUtils;
+
+import javax.annotation.PostConstruct;
+import java.util.LinkedHashSet;
+import java.util.Set;
+
+import static org.springframework.cloud.alibaba.dubbo.autoconfigure.DubboMetadataAutoConfiguration.METADATA_PROTOCOL_BEAN_NAME;
+
+/**
+ * Publishing {@link DubboMetadataConfigService} implementation
+ *
+ * @author <a href="mailto:mercyblitz@gmail.com">Mercy</a>
+ */
+@Service(version = "${spring.application.name}", protocol = METADATA_PROTOCOL_BEAN_NAME)
+// Use current Spring application name as the Dubbo Service version
+public class PublishingDubboMetadataConfigService implements DubboMetadataConfigService {
+
+    /**
+     * A Map to store REST metadata temporary, its' key is the special service name for a Dubbo service,
+     * the value is a JSON content of JAX-RS or Spring MVC REST metadata from the annotated methods.
+     */
+    private final Set<ServiceRestMetadata> serviceRestMetadata = new LinkedHashSet<>();
+
+    private final ObjectMapper objectMapper = new ObjectMapper();
+
+    @PostConstruct
+    public void init() {
+        this.objectMapper.enable(SerializationFeature.INDENT_OUTPUT);
+    }
+
+    /**
+     * Publish the {@link Set} of {@link ServiceRestMetadata}
+     *
+     * @param serviceRestMetadataSet the {@link Set} of {@link ServiceRestMetadata}
+     */
+    public void publishServiceRestMetadata(Set<ServiceRestMetadata> serviceRestMetadataSet) {
+        for (ServiceRestMetadata serviceRestMetadata : serviceRestMetadataSet) {
+            if (!CollectionUtils.isEmpty(serviceRestMetadata.getMeta())) {
+                this.serviceRestMetadata.add(serviceRestMetadata);
+            }
+        }
+    }
+
+    @Override
+    public String getServiceRestMetadata() {
+        String serviceRestMetadataJsonConfig = null;
+        try {
+            serviceRestMetadataJsonConfig = objectMapper.writeValueAsString(serviceRestMetadata);
+        } catch (JsonProcessingException e) {
+            throw new RuntimeException(e);
+        }
+        return serviceRestMetadataJsonConfig;
+    }
+}