Polish spring-cloud-incubator/spring-cloud-alibaba#263

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

@@ -16,7 +16,18 @@
  */
 package org.springframework.cloud.alibaba.dubbo.autoconfigure;
 
+import com.fasterxml.jackson.databind.ObjectMapper;
+import feign.Contract;
+import feign.jaxrs2.JAXRS2Contract;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
+import org.springframework.cloud.alibaba.dubbo.rest.feign.RestMetadataResolver;
+import org.springframework.cloud.openfeign.support.SpringMvcContract;
+import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
+import org.springframework.web.bind.annotation.RequestMapping;
+
+import javax.ws.rs.Path;
 
 /**
  * Spring Boot Auto-Configuration class for Dubbo REST
@@ -26,5 +37,32 @@ import org.springframework.context.annotation.Configuration;
 @Configuration
 public class DubboRestAutoConfiguration {
 
+    /**
+     * A Feign Contract bean for JAX-RS if available
+     */
+    @ConditionalOnClass(Path.class)
+    @Bean
+    public Contract jaxrs2Contract() {
+        return new JAXRS2Contract();
+    }
 
-}
+    @Bean
+    @ConditionalOnMissingBean
+    public ObjectMapper objectMapper() {
+        return new ObjectMapper();
+    }
+
+    /**
+     * A Feign Contract bean for Spring MVC if available
+     */
+    @ConditionalOnClass(RequestMapping.class)
+    @Bean
+    public Contract springMvcContract() {
+        return new SpringMvcContract();
+    }
+
+    @Bean
+    public RestMetadataResolver metadataJsonResolver(ObjectMapper objectMapper) {
+        return new RestMetadataResolver(objectMapper);
+    }
+}

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

@@ -0,0 +1,72 @@
+/*
+ * 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.autoconfigure;
+
+import org.springframework.beans.factory.ListableBeanFactory;
+import org.springframework.beans.factory.SmartInitializingSingleton;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.autoconfigure.AutoConfigureAfter;
+import org.springframework.cloud.client.discovery.DiscoveryClient;
+import org.springframework.cloud.context.named.NamedContextFactory;
+import org.springframework.cloud.openfeign.FeignClient;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.context.event.ContextRefreshedEvent;
+import org.springframework.context.event.EventListener;
+
+import java.util.Map;
+
+/**
+ * The Auto-Configuration class for Dubbo REST Discovery
+ *
+ * @author <a href="mailto:mercyblitz@gmail.com">Mercy</a>
+ */
+@Configuration
+@AutoConfigureAfter(value = {
+        DubboRestAutoConfiguration.class,
+        DubboRestMetadataRegistrationAutoConfiguration.class})
+public class DubboRestDiscoveryAutoConfiguration {
+
+
+    @Autowired
+    private DiscoveryClient discoveryClient;
+
+    // 1. Get all service names from Spring beans that was annotated by @FeignClient
+    // 2. Get all service instances by echo specified service name
+    // 3. Get Rest metadata from service instance
+    // 4. Resolve REST metadata from the @FeignClient instance
+
+    @Bean
+    public SmartInitializingSingleton onBeansInitialized(ListableBeanFactory beanFactory) {
+        return () -> {
+            Map<String, Object> feignClientBeans = beanFactory.getBeansWithAnnotation(FeignClient.class);
+            feignClientBeans.forEach((beanName, bean) -> {
+                if (bean instanceof NamedContextFactory.Specification) {
+                    NamedContextFactory.Specification specification = (NamedContextFactory.Specification) bean;
+                    String serviceName = specification.getName();
+                }
+            });
+        };
+    }
+
+    @EventListener(ContextRefreshedEvent.class)
+    public void onContextRefreshed(ContextRefreshedEvent event) {
+
+    }
+
+
+}

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

@@ -0,0 +1,108 @@
+/*
+ * 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.autoconfigure;
+
+import com.alibaba.dubbo.common.URL;
+import com.alibaba.dubbo.config.spring.ServiceBean;
+import com.alibaba.dubbo.config.spring.context.event.ServiceBeanExportedEvent;
+
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import feign.Contract;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.autoconfigure.AutoConfigureAfter;
+import org.springframework.cloud.alibaba.dubbo.rest.feign.RestMetadataResolver;
+import org.springframework.cloud.client.discovery.event.InstancePreRegisteredEvent;
+import org.springframework.cloud.client.serviceregistry.Registration;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.context.event.EventListener;
+
+import java.util.Collection;
+import java.util.Collections;
+import java.util.LinkedHashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+import java.util.stream.Collectors;
+
+import static org.springframework.cloud.alibaba.dubbo.registry.SpringCloudRegistry.getServiceName;
+
+/**
+ * The Auto-Configuration class for Dubbo REST metadata registration,
+ * REST metadata that is a part of {@link Registration#getMetadata() Spring Cloud service instances' metadata}
+ * will be registered Spring Cloud registry.
+ *
+ * @author <a href="mailto:mercyblitz@gmail.com">Mercy</a>
+ */
+@Configuration
+@AutoConfigureAfter(value = {
+        DubboRestAutoConfiguration.class, DubboServiceRegistrationAutoConfiguration.class})
+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 Map<String, Set<String>> restMetadata = new LinkedHashMap<>();
+
+    /**
+     * Autowire Feign Contract Beans
+     */
+    @Autowired(required = false)
+    private Collection<Contract> contracts = Collections.emptyList();
+
+    @Autowired
+    private ObjectMapper objectMapper;
+
+    @Autowired
+    private RestMetadataResolver restMetadataResolver;
+
+    @EventListener(ServiceBeanExportedEvent.class)
+    public void recordRestMetadata(ServiceBeanExportedEvent event) {
+        ServiceBean serviceBean = event.getServiceBean();
+        List<URL> urls = serviceBean.getExportedUrls();
+        Object bean = serviceBean.getRef();
+
+        Set<String> metadata = contracts.stream()
+                .map(contract -> contract.parseAndValidatateMetadata(bean.getClass()))
+                .flatMap(v -> v.stream())
+                .map(restMetadataResolver::resolve)
+                .collect(Collectors.toSet());
+
+        urls.forEach(url -> {
+            String serviceName = getServiceName(url);
+            restMetadata.put(serviceName, metadata);
+        });
+    }
+
+    /**
+     * Pre-handle Spring Cloud application service registered:
+     * <p>
+     * Put <code>restMetadata</code> with the JSON format into
+     * {@link Registration#getMetadata() service instances' metadata}
+     * <p>
+     *
+     * @param event {@link InstancePreRegisteredEvent} instance
+     */
+    @EventListener(InstancePreRegisteredEvent.class)
+    public void registerRestMetadata(InstancePreRegisteredEvent event) throws JsonProcessingException {
+        Registration registration = event.getRegistration();
+        Map<String, String> serviceInstanceMetadata = registration.getMetadata();
+        String restMetadataJson = objectMapper.writeValueAsString(restMetadata);
+        serviceInstanceMetadata.put("restMetadata", restMetadataJson);
+    }
+}

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

@@ -160,12 +160,12 @@ public class SpringCloudRegistry extends FailbackRegistry {
         return serviceInstance;
     }
 
-    private String getServiceName(URL url) {
+    public static String getServiceName(URL url) {
         String category = url.getParameter(Constants.CATEGORY_KEY, Constants.DEFAULT_CATEGORY);
         return getServiceName(url, category);
     }
 
-    private String getServiceName(URL url, String category) {
+    private static String getServiceName(URL url, String category) {
         StringBuilder serviceNameBuilder = new StringBuilder(category);
         appendIfPresent(serviceNameBuilder, url, Constants.INTERFACE_KEY);
         appendIfPresent(serviceNameBuilder, url, Constants.VERSION_KEY);
@@ -173,7 +173,7 @@ public class SpringCloudRegistry extends FailbackRegistry {
         return serviceNameBuilder.toString();
     }
 
-    private void appendIfPresent(StringBuilder target, URL url, String parameterName) {
+    private static void appendIfPresent(StringBuilder target, URL url, String parameterName) {
         String parameterValue = url.getParameter(parameterName);
         if (StringUtils.hasText(parameterValue)) {
             target.append(SERVICE_NAME_SEPARATOR).append(parameterValue);

spring-cloud-alibaba-dubbo/src/main/java/org/springframework/cloud/alibaba/dubbo/rest/feign/RestMetadataResolver.java

@@ -0,0 +1,74 @@
+/*
+ * 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.rest.feign;
+
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import feign.MethodMetadata;
+import feign.Request;
+import feign.RequestTemplate;
+
+import java.io.IOException;
+import java.util.Collection;
+import java.util.LinkedHashMap;
+import java.util.Map;
+
+/**
+ * The JSON resolver for {@link MethodMetadata}
+ */
+public class RestMetadataResolver {
+
+    private static final String METHOD_PROPERTY_NAME = "method";
+    private static final String URL_PROPERTY_NAME = "url";
+    private static final String HEADERS_PROPERTY_NAME = "headers";
+
+    private final ObjectMapper objectMapper;
+
+    public RestMetadataResolver(ObjectMapper objectMapper) {
+        this.objectMapper = objectMapper;
+    }
+
+    public String resolve(MethodMetadata methodMetadata) {
+        String jsonContent = null;
+        Map<String, Object> metadata = new LinkedHashMap<>();
+        RequestTemplate requestTemplate = methodMetadata.template();
+        Request request = requestTemplate.request();
+        metadata.put(METHOD_PROPERTY_NAME, request.method());
+        metadata.put(URL_PROPERTY_NAME, request.url());
+        metadata.put(HEADERS_PROPERTY_NAME, request.headers());
+        try {
+            jsonContent = objectMapper.writeValueAsString(metadata);
+        } catch (JsonProcessingException e) {
+            throw new IllegalArgumentException(e);
+        }
+        return jsonContent;
+    }
+
+    public Request resolveRequest(String json) {
+        Request request = null;
+        try {
+            Map<String, Object> data = objectMapper.readValue(json, Map.class);
+            String method = (String) data.get(METHOD_PROPERTY_NAME);
+            String url = (String) data.get(URL_PROPERTY_NAME);
+            Map<String, Collection<String>> headers = (Map) data.get(HEADERS_PROPERTY_NAME);
+            request = Request.create(method, url, headers, null, null);
+        } catch (IOException e) {
+            throw new IllegalArgumentException(e);
+        }
+        return request;
+    }
+}