do some enhancements about dubbo spring cloud

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

@@ -19,6 +19,7 @@ import java.util.Collection;
 import java.util.Optional;
 import java.util.function.Supplier;
 
+import com.alibaba.cloud.dubbo.env.DubboCloudProperties;
 import com.alibaba.cloud.dubbo.metadata.DubboProtocolConfigSupplier;
 import com.alibaba.cloud.dubbo.metadata.repository.DubboServiceMetadataRepository;
 import com.alibaba.cloud.dubbo.metadata.repository.MetadataServiceInstanceSelector;
@@ -65,6 +66,9 @@ public class DubboMetadataAutoConfiguration {
 	@Autowired
 	private DubboMetadataServiceExporter dubboMetadataConfigServiceExporter;
 
+	@Autowired
+	private DubboCloudProperties dubboCloudProperties;
+
 	@Bean
 	@ConditionalOnMissingBean
 	public MetadataResolver metadataJsonResolver(ObjectProvider<Contract> contract) {
@@ -89,7 +93,7 @@ public class DubboMetadataAutoConfiguration {
 	@ConditionalOnMissingBean
 	public DubboMetadataServiceProxy dubboMetadataConfigServiceProxy(
 			DubboGenericServiceFactory factory) {
-		return new DubboMetadataServiceProxy(factory);
+		return new DubboMetadataServiceProxy(factory, dubboCloudProperties);
 	}
 
 	// Event-Handling

spring-cloud-alibaba-dubbo/src/main/java/com/alibaba/cloud/dubbo/env/DubboCloudProperties.java

@@ -46,6 +46,18 @@ public class DubboCloudProperties {
 	 */
 	private String subscribedServices = ALL_DUBBO_SERVICES;
 
+	/**
+	 * The Service Instance changed do not means Dubbo service ready, need retry
+	 * mechanism. Retry count of Generic Invoke.
+	 */
+	private int retryCount = 5;
+
+	/**
+	 * The Service Instance changed do not means Dubbo service ready, need retry
+	 * mechanism. Retry interval of Generic Invoke, milliseconds unit.
+	 */
+	private int interval = 10000;
+
 	public String getSubscribedServices() {
 		return subscribedServices;
 	}
@@ -54,6 +66,22 @@ public class DubboCloudProperties {
 		this.subscribedServices = subscribedServices;
 	}
 
+	public int getRetryCount() {
+		return retryCount;
+	}
+
+	public void setRetryCount(int retryCount) {
+		this.retryCount = retryCount;
+	}
+
+	public int getInterval() {
+		return interval;
+	}
+
+	public void setInterval(int interval) {
+		this.interval = interval;
+	}
+
 	/**
 	 * Get the subscribed services as a {@link Set} with configuration order.
 	 *

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

@@ -19,6 +19,8 @@ import java.lang.reflect.InvocationHandler;
 import java.lang.reflect.Method;
 import java.util.stream.Stream;
 
+import com.alibaba.cloud.dubbo.env.DubboCloudProperties;
+
 import org.apache.dubbo.rpc.service.GenericService;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -34,8 +36,12 @@ class DubboMetadataServiceInvocationHandler implements InvocationHandler {
 
 	private final GenericService genericService;
 
+	private final DubboCloudProperties dubboCloudProperties;
+
 	DubboMetadataServiceInvocationHandler(String serviceName, String version,
-			DubboGenericServiceFactory dubboGenericServiceFactory) {
+			DubboGenericServiceFactory dubboGenericServiceFactory,
+			DubboCloudProperties dubboCloudProperties) {
+		this.dubboCloudProperties = dubboCloudProperties;
 		this.genericService = dubboGenericServiceFactory.create(serviceName,
 				DubboMetadataService.class, version);
 	}
@@ -43,13 +49,16 @@ class DubboMetadataServiceInvocationHandler implements InvocationHandler {
 	@Override
 	public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
 		Object returnValue = null;
-		try {
+		for (int i = 1; i <= dubboCloudProperties.getRetryCount(); i++) {
-			returnValue = genericService.$invoke(method.getName(),
+			try {
-					getParameterTypes(method), args);
+				returnValue = genericService.$invoke(method.getName(),
-		}
+						getParameterTypes(method), args);
-		catch (Throwable e) {
+			}
-			if (logger.isErrorEnabled()) {
+			catch (Throwable e) {
-				logger.error(e.getMessage(), e);
+				if (logger.isErrorEnabled()) {
+					logger.error("[failed " + i + " times] " + e.getMessage(), e);
+				}
+				Thread.sleep(dubboCloudProperties.getInterval() * i);
 			}
 		}
 		return returnValue;

spring-cloud-alibaba-dubbo/src/main/java/com/alibaba/cloud/dubbo/service/DubboMetadataServiceProxy.java

@@ -18,6 +18,8 @@ package com.alibaba.cloud.dubbo.service;
 import java.util.Map;
 import java.util.concurrent.ConcurrentHashMap;
 
+import com.alibaba.cloud.dubbo.env.DubboCloudProperties;
+
 import org.springframework.beans.factory.BeanClassLoaderAware;
 import org.springframework.beans.factory.DisposableBean;
 
@@ -32,13 +34,17 @@ public class DubboMetadataServiceProxy implements BeanClassLoaderAware, Disposab
 
 	private final DubboGenericServiceFactory dubboGenericServiceFactory;
 
+	private final DubboCloudProperties dubboCloudProperties;
+
 	private final Map<String, DubboMetadataService> dubboMetadataServiceCache = new ConcurrentHashMap<>();
 
 	private ClassLoader classLoader;
 
 	public DubboMetadataServiceProxy(
-			DubboGenericServiceFactory dubboGenericServiceFactory) {
+			DubboGenericServiceFactory dubboGenericServiceFactory,
+			DubboCloudProperties dubboCloudProperties) {
 		this.dubboGenericServiceFactory = dubboGenericServiceFactory;
+		this.dubboCloudProperties = dubboCloudProperties;
 	}
 
 	/**
@@ -91,7 +97,7 @@ public class DubboMetadataServiceProxy implements BeanClassLoaderAware, Disposab
 		return (DubboMetadataService) newProxyInstance(classLoader,
 				new Class[] { DubboMetadataService.class },
 				new DubboMetadataServiceInvocationHandler(serviceName, version,
-						dubboGenericServiceFactory));
+						dubboGenericServiceFactory, dubboCloudProperties));
 	}
 
 }