spring - 无法使用 Spring Cloud Consul 和 @EnableDiscoveryClient 连接 RestTemplate

Question

我正在尝试评估使用 Consul 进行服务发现，但是对于一个简单的项目，RestTemplate 不是自动连接的。使用 Spring Cloud Consul 1.0.0.M6 和 Spring Boot 1.3.3。

在 Consul UI 中可以看到我的“多媒体”服务注册了，如果我在下面的代码中注释掉 RestTemplate 的使用，我可以看到服务实例信息。

目前是否支持使用 1.0.0.M6 进行 Consul 发现的 RestTemplate 自动连接？如果是这样，是否可以分享工作示例？

我也有一个非常相似的项目，使用 Eureka 可以正常工作，我只是将 @EnableEurekaClient 注释更改为 @EnableDiscoveryClient 并在 bootstrap.properties 文件中设置领事主机和端口。在阅读 Spring Cloud Consul 文档时，功能应该几乎相同—— RestTemplate 自动连接并准备好使用 http://>/some/path URL 中的服务。

代码如下:

package com.trta.cps;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.CommandLineRunner;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.builder.SpringApplicationBuilder;
import org.springframework.cloud.client.discovery.DiscoveryClient;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
import org.springframework.web.client.RestTemplate;

@SpringBootApplication
@EnableDiscoveryClient
public class CpsMultimediaServiceClientApplication implements CommandLineRunner {

    @Autowired
    DiscoveryClient discoveryClient;

    @Autowired
    private RestTemplate restTemplate;

    public static void main(String[] args) {
        new SpringApplicationBuilder(CpsMultimediaServiceClientApplication.class).web(false)
                                                                                 .run(args);
    }

    @Override
    public void run(String... args) throws Exception {
        discoveryClient.getServices()
                       .forEach(System.out::println);
        discoveryClient.getInstances("multimedia")
                       .forEach(System.out::println);

        String result = this.restTemplate.getForObject("http://multimedia/v1/multimedia/{guid}/info", String.class, "A3E766B4000000E8199D0CA7000002F2");
        System.out.println("Response: " + result);
    }
}

这是我的 build.gradle:

buildscript {
    ext {
        springBootVersion = '1.3.3.RELEASE'
    }
    repositories {
        mavenCentral()
    }
    dependencies {
        classpath("org.springframework.boot:spring-boot-gradle-plugin:${springBootVersion}")
    }
}

apply plugin: 'java'
apply plugin: 'eclipse'
apply plugin: 'spring-boot'

jar {
    baseName = 'cps-multimedia-service-client'
    version = '0.0.1-SNAPSHOT'
}
sourceCompatibility = 1.8
targetCompatibility = 1.8

repositories {
    mavenCentral()
    maven { url "https://repo.spring.io/snapshot" }
    maven { url "https://repo.spring.io/milestone" }
    maven { url 'https://repo.spring.io/libs-milestone' }

}


dependencies {
    compile 'org.springframework.cloud:spring-cloud-starter-consul-all:1.0.0.M6'

    testCompile('org.springframework.boot:spring-boot-starter-test')
}

dependencyManagement {
    imports {
        mavenBom "org.springframework.cloud:spring-cloud-dependencies:Brixton.BUILD-SNAPSHOT"
    }
}

eclipse {
    classpath {
        containers.remove('org.eclipse.jdt.launching.JRE_CONTAINER')
        containers 'org.eclipse.jdt.launching.JRE_CONTAINER/org.eclipse.jdt.internal.debug.ui.launcher.StandardVMType/JavaSE-1.8'
    }
}

task wrapper(type: Wrapper) {
    gradleVersion = '2.9'
}

这是完整的堆栈跟踪:

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'cpsMultimediaServiceClientApplication': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: private org.springframework.web.client.RestTemplate com.trta.cps.CpsMultimediaServiceClientApplication.restTemplate; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [org.springframework.web.client.RestTemplate] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:334) ~[spring-beans-4.2.5.RELEASE.jar:4.2.5.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1214) ~[spring-beans-4.2.5.RELEASE.jar:4.2.5.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:543) ~[spring-beans-4.2.5.RELEASE.jar:4.2.5.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:482) ~[spring-beans-4.2.5.RELEASE.jar:4.2.5.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306) ~[spring-beans-4.2.5.RELEASE.jar:4.2.5.RELEASE]
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230) ~[spring-beans-4.2.5.RELEASE.jar:4.2.5.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302) ~[spring-beans-4.2.5.RELEASE.jar:4.2.5.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:197) ~[spring-beans-4.2.5.RELEASE.jar:4.2.5.RELEASE]
at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:772) ~[spring-beans-4.2.5.RELEASE.jar:4.2.5.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:839) ~[spring-context-4.2.5.RELEASE.jar:4.2.5.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:538) ~[spring-context-4.2.5.RELEASE.jar:4.2.5.RELEASE]
at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:766) ~[spring-boot-1.3.3.RELEASE.jar:1.3.3.RELEASE]
at org.springframework.boot.SpringApplication.createAndRefreshContext(SpringApplication.java:361) ~[spring-boot-1.3.3.RELEASE.jar:1.3.3.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:307) ~[spring-boot-1.3.3.RELEASE.jar:1.3.3.RELEASE]
at org.springframework.boot.builder.SpringApplicationBuilder.run(SpringApplicationBuilder.java:134) [spring-boot-1.3.3.RELEASE.jar:1.3.3.RELEASE]
at com.trta.cps.CpsMultimediaServiceClientApplication.main(CpsMultimediaServiceClientApplication.java:29) [main/:na]
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_25]
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_25]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_25]
at java.lang.reflect.Method.invoke(Method.java:483) ~[na:1.8.0_25]
at com.intellij.rt.execution.application.AppMain.main(AppMain.java:140) [idea_rt.jar:na]
Caused by: org.springframework.beans.factory.BeanCreationException: Could not autowire field: private org.springframework.web.client.RestTemplate com.trta.cps.CpsMultimediaServiceClientApplication.restTemplate; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [org.springframework.web.client.RestTemplate] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:573) ~[spring-beans-4.2.5.RELEASE.jar:4.2.5.RELEASE]
at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:88) ~[spring-beans-4.2.5.RELEASE.jar:4.2.5.RELEASE]
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:331) ~[spring-beans-4.2.5.RELEASE.jar:4.2.5.RELEASE]
... 20 common frames omitted
Caused by: org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [org.springframework.web.client.RestTemplate] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}
at org.springframework.beans.factory.support.DefaultListableBeanFactory.raiseNoSuchBeanDefinitionException(DefaultListableBeanFactory.java:1373) ~[spring-beans-4.2.5.RELEASE.jar:4.2.5.RELEASE]
at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1119) ~[spring-beans-4.2.5.RELEASE.jar:4.2.5.RELEASE]
at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1014) ~[spring-beans-4.2.5.RELEASE.jar:4.2.5.RELEASE]
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:545) ~[spring-beans-4.2.5.RELEASE.jar:4.2.5.RELEASE]
... 22 common frames omitted

Answer 1

我们对 RestTemplate 的配置方式进行了更改。它不再为您创建。见 updated docs .你需要自己创建一个 RestTemplate bean。

@Configuration
public class MyConfiguration {

    @LoadBalanced
    @Bean
    RestTemplate restTemplate() {
        return new RestTemplate();
    }
}

public class MyClass {
    @Autowired
    private RestTemplate restTemplate;

    public String doOtherStuff() {
        String results = restTemplate.getForObject("http://stores/stores", String.class);
        return results;
    }
}