1. fix router rest template strong dependency on RouterLabelResolver

2. optimize RouterLabelResolver to list
3. add metadata-transfer dependency for router

CHANGELOG.md

@@ -6,3 +6,5 @@
 - [Feature: Router support request label.](https://github.com/Tencent/spring-cloud-tencent/pull/165)
 - [Feature: Support router expression label](https://github.com/Tencent/spring-cloud-tencent/pull/190)
 - [Add metadata transfer example.](https://github.com/Tencent/spring-cloud-tencent/pull/184)
+- [Feature: Support metadata router.](https://github.com/Tencent/spring-cloud-tencent/pull/191)
+- [Feature: Misc optimize metadata router.](https://github.com/Tencent/spring-cloud-tencent/pull/192)

spring-cloud-starter-tencent-polaris-router/pom.xml

@@ -19,6 +19,10 @@
 			<groupId>com.tencent.cloud</groupId>
 			<artifactId>spring-cloud-tencent-polaris-loadbalancer</artifactId>
 		</dependency>
+		<dependency>
+			<groupId>com.tencent.cloud</groupId>
+			<artifactId>spring-cloud-starter-tencent-metadata-transfer</artifactId>
+		</dependency>
 		<!-- Spring Cloud Tencent dependencies end -->
 
 		<!-- Polaris dependencies start -->

spring-cloud-starter-tencent-polaris-router/src/main/java/com/tencent/cloud/polaris/router/config/RouterAutoConfiguration.java

@@ -18,11 +18,13 @@
 
 package com.tencent.cloud.polaris.router.config;
 
+import java.util.List;
+
 import com.tencent.cloud.common.metadata.config.MetadataLocalProperties;
 import com.tencent.cloud.polaris.context.ServiceRuleManager;
 import com.tencent.cloud.polaris.router.RouterRuleLabelResolver;
 import com.tencent.cloud.polaris.router.feign.PolarisCachingSpringLoadBalanceFactory;
-import com.tencent.cloud.polaris.router.feign.RouterLabelInterceptor;
+import com.tencent.cloud.polaris.router.feign.RouterLabelFeignInterceptor;
 import com.tencent.cloud.polaris.router.resttemplate.PolarisLoadBalancerBeanPostProcessor;
 import com.tencent.cloud.polaris.router.spi.RouterLabelResolver;
 
@@ -45,10 +47,10 @@ import static org.springframework.core.Ordered.HIGHEST_PRECEDENCE;
 public class RouterAutoConfiguration {
 
 	@Bean
-	public RouterLabelInterceptor routerLabelInterceptor(@Nullable RouterLabelResolver resolver,
+	public RouterLabelFeignInterceptor routerLabelInterceptor(@Nullable List<RouterLabelResolver> routerLabelResolvers,
 			MetadataLocalProperties metadataLocalProperties,
 			RouterRuleLabelResolver routerRuleLabelResolver) {
-		return new RouterLabelInterceptor(resolver, metadataLocalProperties, routerRuleLabelResolver);
+		return new RouterLabelFeignInterceptor(routerLabelResolvers, metadataLocalProperties, routerRuleLabelResolver);
 	}
 
 	@Bean

spring-cloud-starter-tencent-polaris-router/src/main/java/com/tencent/cloud/polaris/router/feign/RouterLabelFeignInterceptor.java

@@ -19,7 +19,9 @@
 package com.tencent.cloud.polaris.router.feign;
 
 import java.util.Collections;
+import java.util.Comparator;
 import java.util.HashMap;
+import java.util.List;
 import java.util.Map;
 import java.util.Set;
 
@@ -44,17 +46,23 @@ import org.springframework.util.CollectionUtils;
  *
  *@author lepdou 2022-05-12
  */
-public class RouterLabelInterceptor implements RequestInterceptor, Ordered {
-	private static final Logger LOGGER = LoggerFactory.getLogger(RouterLabelInterceptor.class);
+public class RouterLabelFeignInterceptor implements RequestInterceptor, Ordered {
+	private static final Logger LOGGER = LoggerFactory.getLogger(RouterLabelFeignInterceptor.class);
 
-	private final RouterLabelResolver resolver;
+	private final List<RouterLabelResolver> routerLabelResolvers;
 	private final MetadataLocalProperties metadataLocalProperties;
 	private final RouterRuleLabelResolver routerRuleLabelResolver;
 
-	public RouterLabelInterceptor(RouterLabelResolver resolver,
+	public RouterLabelFeignInterceptor(List<RouterLabelResolver> routerLabelResolvers,
 			MetadataLocalProperties metadataLocalProperties,
 			RouterRuleLabelResolver routerRuleLabelResolver) {
-		this.resolver = resolver;
+		if (!CollectionUtils.isEmpty(routerLabelResolvers)) {
+			routerLabelResolvers.sort(Comparator.comparingInt(Ordered::getOrder));
+			this.routerLabelResolvers = routerLabelResolvers;
+		}
+		else {
+			this.routerLabelResolvers = null;
+		}
 		this.metadataLocalProperties = metadataLocalProperties;
 		this.routerRuleLabelResolver = routerRuleLabelResolver;
 	}
@@ -74,7 +82,8 @@ public class RouterLabelInterceptor implements RequestInterceptor, Ordered {
 		labels.putAll(transitiveLabels);
 
 		// labels from request
-		if (resolver != null) {
+		if (!CollectionUtils.isEmpty(routerLabelResolvers)) {
+			routerLabelResolvers.forEach(resolver -> {
 				try {
 					Map<String, String> customResolvedLabels = resolver.resolve(requestTemplate);
 					if (!CollectionUtils.isEmpty(customResolvedLabels)) {
@@ -84,6 +93,7 @@ public class RouterLabelInterceptor implements RequestInterceptor, Ordered {
 				catch (Throwable t) {
 					LOGGER.error("[SCT][Router] revoke RouterLabelResolver occur some exception. ", t);
 				}
+			});
 		}
 
 		// labels from rule expression

spring-cloud-starter-tencent-polaris-router/src/main/java/com/tencent/cloud/polaris/router/resttemplate/PolarisLoadBalancerBeanPostProcessor.java

@@ -18,7 +18,10 @@
 
 package com.tencent.cloud.polaris.router.resttemplate;
 
+import java.util.List;
+
 import com.tencent.cloud.common.metadata.config.MetadataLocalProperties;
+import com.tencent.cloud.common.util.BeanFactoryUtils;
 import com.tencent.cloud.polaris.router.RouterRuleLabelResolver;
 import com.tencent.cloud.polaris.router.spi.RouterLabelResolver;
 
@@ -50,12 +53,12 @@ public class PolarisLoadBalancerBeanPostProcessor implements BeanPostProcessor,
 		if (bean instanceof LoadBalancerInterceptor) {
 			LoadBalancerRequestFactory requestFactory = this.factory.getBean(LoadBalancerRequestFactory.class);
 			LoadBalancerClient loadBalancerClient = this.factory.getBean(LoadBalancerClient.class);
-			RouterLabelResolver routerLabelResolver = this.factory.getBean(RouterLabelResolver.class);
+			List<RouterLabelResolver> routerLabelResolvers = BeanFactoryUtils.getBeans(factory, RouterLabelResolver.class);
 			MetadataLocalProperties metadataLocalProperties = this.factory.getBean(MetadataLocalProperties.class);
 			RouterRuleLabelResolver routerRuleLabelResolver = this.factory.getBean(RouterRuleLabelResolver.class);
 
 			return new PolarisLoadBalancerInterceptor(loadBalancerClient, requestFactory,
-					routerLabelResolver, metadataLocalProperties, routerRuleLabelResolver);
+					routerLabelResolvers, metadataLocalProperties, routerRuleLabelResolver);
 		}
 		return bean;
 	}

spring-cloud-starter-tencent-polaris-router/src/main/java/com/tencent/cloud/polaris/router/resttemplate/PolarisLoadBalancerInterceptor.java

@@ -21,7 +21,9 @@ package com.tencent.cloud.polaris.router.resttemplate;
 import java.io.IOException;
 import java.net.URI;
 import java.util.Collections;
+import java.util.Comparator;
 import java.util.HashMap;
+import java.util.List;
 import java.util.Map;
 import java.util.Set;
 
@@ -39,6 +41,7 @@ import org.springframework.cloud.client.loadbalancer.LoadBalancerClient;
 import org.springframework.cloud.client.loadbalancer.LoadBalancerInterceptor;
 import org.springframework.cloud.client.loadbalancer.LoadBalancerRequestFactory;
 import org.springframework.cloud.netflix.ribbon.RibbonLoadBalancerClient;
+import org.springframework.core.Ordered;
 import org.springframework.http.HttpRequest;
 import org.springframework.http.client.ClientHttpRequestExecution;
 import org.springframework.http.client.ClientHttpResponse;
@@ -56,7 +59,7 @@ public class PolarisLoadBalancerInterceptor extends LoadBalancerInterceptor {
 
 	private final LoadBalancerClient loadBalancer;
 	private final LoadBalancerRequestFactory requestFactory;
-	private final RouterLabelResolver resolver;
+	private final List<RouterLabelResolver> routerLabelResolvers;
 	private final MetadataLocalProperties metadataLocalProperties;
 	private final RouterRuleLabelResolver routerRuleLabelResolver;
 
@@ -64,16 +67,23 @@ public class PolarisLoadBalancerInterceptor extends LoadBalancerInterceptor {
 
 	public PolarisLoadBalancerInterceptor(LoadBalancerClient loadBalancer,
 			LoadBalancerRequestFactory requestFactory,
-			RouterLabelResolver resolver,
+			List<RouterLabelResolver> routerLabelResolvers,
 			MetadataLocalProperties metadataLocalProperties,
 			RouterRuleLabelResolver routerRuleLabelResolver) {
 		super(loadBalancer, requestFactory);
 		this.loadBalancer = loadBalancer;
 		this.requestFactory = requestFactory;
-		this.resolver = resolver;
 		this.metadataLocalProperties = metadataLocalProperties;
 		this.routerRuleLabelResolver = routerRuleLabelResolver;
 
+		if (!CollectionUtils.isEmpty(routerLabelResolvers)) {
+			routerLabelResolvers.sort(Comparator.comparingInt(Ordered::getOrder));
+			this.routerLabelResolvers = routerLabelResolvers;
+		}
+		else {
+			this.routerLabelResolvers = null;
+		}
+
 		this.isRibbonLoadBalanceClient = loadBalancer instanceof RibbonLoadBalancerClient;
 	}
 
@@ -104,7 +114,8 @@ public class PolarisLoadBalancerInterceptor extends LoadBalancerInterceptor {
 		labels.putAll(transitiveLabels);
 
 		// labels from request
-		if (resolver != null) {
+		if (!CollectionUtils.isEmpty(routerLabelResolvers)) {
+			routerLabelResolvers.forEach(resolver -> {
 				try {
 					Map<String, String> customResolvedLabels = resolver.resolve(request, body);
 					if (!CollectionUtils.isEmpty(customResolvedLabels)) {
@@ -114,6 +125,7 @@ public class PolarisLoadBalancerInterceptor extends LoadBalancerInterceptor {
 				catch (Throwable t) {
 					LOGGER.error("[SCT][Router] revoke RouterLabelResolver occur some exception. ", t);
 				}
+			});
 		}
 
 		// labels from rule expression

spring-cloud-starter-tencent-polaris-router/src/main/java/com/tencent/cloud/polaris/router/spi/RouterLabelResolver.java

@@ -22,6 +22,7 @@ import java.util.Map;
 
 import feign.RequestTemplate;
 
+import org.springframework.core.Ordered;
 import org.springframework.http.HttpRequest;
 
 /**
@@ -29,7 +30,7 @@ import org.springframework.http.HttpRequest;
  *
  * @author lepdou 2022-05-11
  */
-public interface RouterLabelResolver {
+public interface RouterLabelResolver extends Ordered {
 
 	/**
 	 * resolve labels from feign request.

spring-cloud-tencent-commons/src/main/java/com/tencent/cloud/common/util/BeanFactoryUtils.java

@@ -0,0 +1,51 @@
+/*
+ * Tencent is pleased to support the open source community by making Spring Cloud Tencent available.
+ *
+ * Copyright (C) 2019 THL A29 Limited, a Tencent company. All rights reserved.
+ *
+ * Licensed under the BSD 3-Clause License (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * https://opensource.org/licenses/BSD-3-Clause
+ *
+ * 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 com.tencent.cloud.common.util;
+
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.List;
+import java.util.stream.Collectors;
+
+import org.springframework.beans.factory.BeanFactory;
+import org.springframework.beans.factory.support.DefaultListableBeanFactory;
+
+/**
+ * the utils for bean factory.
+ * @author lepdou 2022-05-23
+ */
+public class BeanFactoryUtils {
+
+	public static <T> List<T> getBeans(BeanFactory beanFactory, Class<T> requiredType) {
+		if (!(beanFactory instanceof DefaultListableBeanFactory)) {
+			throw new RuntimeException("bean factory not support get list bean. factory type = " + beanFactory.getClass()
+					.getName());
+		}
+
+		String[] beanNames = ((DefaultListableBeanFactory) beanFactory).getBeanNamesForType(requiredType);
+
+		if (beanNames.length == 0) {
+			return Collections.emptyList();
+		}
+
+		return Arrays.stream(beanNames).map(
+				beanName -> beanFactory.getBean(beanName, requiredType)
+		).collect(Collectors.toList());
+	}
+}

spring-cloud-tencent-examples/polaris-router-example/router-caller-service/src/main/java/com/tencent/cloud/polaris/router/example/CustomRouterLabelResolver.java

@@ -57,4 +57,9 @@ public class CustomRouterLabelResolver implements RouterLabelResolver {
 		labels.put("user", user.getName());
 		return labels;
 	}
+
+	@Override
+	public int getOrder() {
+		return 0;
+	}
 }