Disconnected from the target VM, address: '127.0.0.1:51233', transport: 'socket'

Eureka Client的使用

使用IDEA创建一个Spring Initializr项目，在勾选模块的时候需要选择Eureka Discovery，如下:

项目生成的pom.xml文件内容如下：

1. <?xml version="1.0" encoding="UTF-8"?>
2.  <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
3.  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
4.  <modelVersion>4.0.0</modelVersion>
5.   
6.  <groupId>org.zero.eureka</groupId>
7.  <artifactId>client</artifactId>
8.  <version>0.0.1-SNAPSHOT</version>
9.  <packaging>jar</packaging>
10.  
11.  <name>client</name>
12.  <description>Demo project for Spring Boot</description>
13.  
14.  <parent>
15.  <groupId>org.springframework.boot</groupId>
16.  <artifactId>spring-boot-starter-parent</artifactId>
17.  <version>2.0.4.RELEASE</version>
18.  <relativePath/> <!-- lookup parent from repository -->
19.  </parent>
20.   
21.  <properties>
22.  <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
23.  <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
24.  <java.version>1.8</java.version>
25.  <spring-cloud.version>Finchley.SR1</spring-cloud.version>
26.  </properties>
27.  
28.  <dependencies>
29.  <dependency>
30.  <groupId>org.springframework.cloud</groupId>
31.  <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
32.  </dependency>
33.   
34.  <dependency>
35.  <groupId>org.springframework.boot</groupId>
36.  <artifactId>spring-boot-starter-test</artifactId>
37.  <scope>test</scope>
38.  </dependency>
39.  </dependencies>
40.   
41.  <dependencyManagement>
42.  <dependencies>
43.  <dependency>
44.  <groupId>org.springframework.cloud</groupId>
45.  <artifactId>spring-cloud-dependencies</artifactId>
46.  <version>${spring-cloud.version}</version> 
47. <type>pom</type>
48.  <scope>import</scope>
49.  </dependency>
50.  </dependencies>
51.  </dependencyManagement>
52.   
53.  <build>
54.  <plugins>
55.  <plugin>
56.  <groupId>org.springframework.boot</groupId>
57.  <artifactId>spring-boot-maven-plugin</artifactId>
58.  </plugin>
59.  </plugins>
60.  </build> 
61. </project>

项目的依赖都加载完成后，在启动类中加上@EnableDiscoveryClient，声明这是一个eureka client，否则不会进行服务注册：

1. package org.zero.eureka.client;
2.  
3.  import org.springframework.boot.SpringApplication;
4.  import org.springframework.boot.autoconfigure.SpringBootApplication;
5.  import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
6.   
7. @SpringBootApplication
8. @EnableDiscoveryClient
9.  public class ClientApplication {
10.  
11.  public static void main(String[] args) {
12.  SpringApplication.run(ClientApplication.class, args);
13.  }
14. }

接着就是在application.yml配置文件中，配置注册中心即eureka server的地址，以及项目的名称和启动端口号。如下：

1.  eureka: 
2.       client:
3.  　　service-url:
4.            defaultZone: http://localhost:8761/eureka/
5.  spring:
6.    application:
7.      name: eureka-client
8.  server:
9.    port: 9088

完成以上配置后，即可启动项目。但是我这里启动项目的时候失败了，控制台输出如下警告信息：

Invocation of destroy method failed on bean with name 'scopedTarget.eurekaClient': org.springframework.beans.factory.BeanCreationNotAllowedException: Error creating bean with name 'eurekaInstanceConfigBean': Singleton bean creation not allowed while singletons of this factory are in destruction (Do not request a bean from a BeanFactory in a destroy method implementation!)

这是因为client里不包含Tomcat的依赖，所以Spring容器无法创建一些实例，从而导致项目无法启动，只需在pom.xml文件中，加上web依赖即可：

1.  <dependency>
2.  <groupId>org.springframework.boot</groupId>
3.  <artifactId>spring-boot-starter-web</artifactId>
4.  </dependency>

项目启动成功后，可以在eureka server的信息面板中查看到已注册的实例信息，如下：