Polish spring-cloud-incubator/spring-cloud-alibaba#559 : Refactor and filter protocol

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

@@ -322,8 +322,8 @@ public class DubboServiceMetadataRepository {
         return hasText(protocolPort) ? Integer.valueOf(protocolPort) : null;
     }
 
-    public List<URL> getExportedURLs(String serviceInstance, String group, String version) {
+    public List<URL> getExportedURLs(String serviceInterface, String group, String version) {
-        String serviceKey = URL.buildKey(serviceInstance, group, version);
+        String serviceKey = URL.buildKey(serviceInterface, group, version);
         return allExportedURLs.getOrDefault(serviceKey, Collections.emptyList());
     }
 

spring-cloud-alibaba-dubbo/src/main/java/org/springframework/cloud/alibaba/dubbo/registry/AbstractSpringCloudRegistry.java

@@ -172,15 +172,11 @@ public abstract class AbstractSpringCloudRegistry extends FailbackRegistry {
                 .map(dubboMetadataConfigServiceProxy::getProxy)
                 .filter(Objects::nonNull)
                 .forEach(dubboMetadataService -> {
-                    String serviceInterface = url.getServiceInterface();
+                    List<URL> exportedURLs = getExportedURLs(dubboMetadataService, url);
-                    String group = url.getParameter(GROUP_KEY);
-                    String version = url.getParameter(VERSION_KEY);
-                    String exportedURLsJSON = dubboMetadataService.getExportedURLs(serviceInterface, group, version);
-                    List<URL> exportedURLs = jsonUtils.toURLs(exportedURLsJSON);
                     List<URL> allSubscribedURLs = new LinkedList<>();
                     for (URL exportedURL : exportedURLs) {
                         String serviceName = exportedURL.getParameter(APPLICATION_KEY);
-                        List<ServiceInstance> serviceInstances = discoveryClient.getInstances(serviceName);
+                        List<ServiceInstance> serviceInstances = getServiceInstances(serviceName);
                         String protocol = exportedURL.getProtocol();
                         List<URL> subscribedURLs = new LinkedList<>();
                         serviceInstances.forEach(serviceInstance -> {
@@ -209,6 +205,21 @@ public abstract class AbstractSpringCloudRegistry extends FailbackRegistry {
                 });
     }
 
+    private List<URL> getExportedURLs(DubboMetadataService dubboMetadataService, URL url) {
+        String serviceInterface = url.getServiceInterface();
+        String group = url.getParameter(GROUP_KEY);
+        String version = url.getParameter(VERSION_KEY);
+        // The subscribed protocol may be null
+        String subscribedProtocol = url.getParameter(PROTOCOL_KEY);
+        String exportedURLsJSON = dubboMetadataService.getExportedURLs(serviceInterface, group, version);
+        return jsonUtils
+                .toURLs(exportedURLsJSON)
+                .stream()
+                .filter(exportedURL ->
+                        subscribedProtocol == null || subscribedProtocol.equalsIgnoreCase(exportedURL.getProtocol())
+                ).collect(Collectors.toList());
+    }
+
 
     private void subscribeDubboMetadataServiceURLs(URL url, NotifyListener listener) {
         String serviceInterface = url.getServiceInterface();

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

@@ -64,13 +64,13 @@ public interface DubboMetadataService {
     Map<String, String> getAllExportedURLs();
 
     /**
-     * Get the json content of an exported List<URL> of {@link URL URLs} by the serviceInstance , group and version
+     * Get the json content of an exported List<URL> of {@link URL URLs} by the serviceInterface , group and version
      *
-     * @param serviceInstance The class name of service interface
+     * @param serviceInterface The class name of service interface
      * @param group           {@link Service#group() the service group} (optional)
      * @param version         {@link Service#version() the service version} (optional)
      * @return non-null read-only {@link List}
      * @see URL
      */
-    String getExportedURLs(String serviceInstance, String group, String version);
+    String getExportedURLs(String serviceInterface, String group, String version);
 }

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

@@ -18,6 +18,9 @@ package org.springframework.cloud.alibaba.dubbo.service;
 
 import org.apache.dubbo.rpc.service.GenericService;
 
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
 import java.lang.reflect.InvocationHandler;
 import java.lang.reflect.Method;
 import java.util.stream.Stream;
@@ -29,14 +32,7 @@ import java.util.stream.Stream;
  */
 class DubboMetadataServiceInvocationHandler implements InvocationHandler {
 
-    /**
+    private final Logger logger = LoggerFactory.getLogger(getClass());
-     * The method name of {@link DubboMetadataService#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;
 
@@ -46,7 +42,15 @@ class DubboMetadataServiceInvocationHandler implements InvocationHandler {
 
     @Override
     public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
-        return genericService.$invoke(method.getName(), getParameterTypes(method), args);
+        Object returnValue = null;
+        try {
+            returnValue = genericService.$invoke(method.getName(), getParameterTypes(method), args);
+        } catch (Throwable e) {
+            if (logger.isErrorEnabled()) {
+                logger.error(e.getMessage(), e);
+            }
+        }
+        return returnValue;
     }
 
     private String[] getParameterTypes(Method method) {

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

@@ -84,8 +84,8 @@ public class IntrospectiveDubboMetadataService implements DubboMetadataService {
     }
 
     @Override
-    public String getExportedURLs(String serviceInstance, String group, String version) {
+    public String getExportedURLs(String serviceInterface, String group, String version) {
-        List<URL> urls = dubboServiceMetadataRepository.getExportedURLs(serviceInstance, group, version);
+        List<URL> urls = dubboServiceMetadataRepository.getExportedURLs(serviceInterface, group, version);
         return jsonUtils.toJSON(urls);
     }
 }