SpringCloud的学习记录(2)

这一章节主要讲如何搭建eureka-client项目.

在我们生成的Demo项目上右键点击New->Module->spring Initializr, 然后next, 填写Group和Artifact等信息，

这里Artifact填写eurekaclient, 再次next,

这里选择的Web下的web和Cloud Discovery下的Eureka Discovery.

最后在Module Name中填写eureka-client.

生成的pom.xml文件如下:

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.1.3.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.xum</groupId>
    <artifactId>eureka-client</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>eureka-client</name>
    <description>Demo project for Spring Boot</description>
    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <java.version>1.8</java.version>
        <spring-cloud.version>Greenwich.RELEASE</spring-cloud.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>
    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>${spring-cloud.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>
    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>
    <repositories>
        <repository>
            <id>spring-milestones</id>
            <name>Spring Milestones</name>
            <url>https://repo.spring.io/milestone</url>
        </repository>
    </repositories>
</project>

然后在EurekaClientApplication上加@EnableEurekaClient注解:

package com.xum.eurekaclient;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.netflix.eureka.EnableEurekaClient;

@EnableEurekaClient
@SpringBootApplication
public class EurekaClientApplication {

    public static void main(String[] args) {
        SpringApplication.run(EurekaClientApplication.class, args);
    }

}

然后新建application.yml文件, 内容如下:

eureka:
  client:
    serviceUrl:
      defaultZone: http://localhost:8761/eureka/    这里的defaultZone是上一章节的对应eureka-server
server:
  port: 8762
spring:
  application:
    name: eureka-client

然后写一个controller去获取数据, 这里是获取git上的数据, 关于config-server的项目下一章节说

package com.xum.eurekaclient.controller;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.cloud.client.ServiceInstance;
import org.springframework.cloud.client.discovery.DiscoveryClient;
import org.springframework.cloud.context.config.annotation.RefreshScope;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;

import java.lang.reflect.Method;
import java.util.List;

@RefreshScope   //这里加上RefreshScope注解,这样才能获取到git上的内容
@RestController
@RequestMapping(value = "/testone")
public class TestOneController {

    private static final Logger LOG = LoggerFactory.getLogger(TestOneController.class);

    @Autowired
    private DiscoveryClient discoveryClient;

    @Value("${server.port}")
    String port;

    /* from git config */
    @Value("${democonfigclient.message}")
    String message;

    /* from git config */
    @Value("${foo}")
    String foo;

    @RequestMapping(value = "/test")
    public String test(@RequestParam(value = "name", required = false, defaultValue = "testOneClient")String name) {
        /*List<ServiceInstance> list = discoveryClient.getInstances("eureka-client");
        LOG.info("discoveryClient.getServices().size() = " + discoveryClient.getServices().size());
        for( String s :  discoveryClient.getServices()){
            List<ServiceInstance> serviceInstances =  discoveryClient.getInstances(s);
            for(ServiceInstance si : serviceInstances){
                LOG.info("services:" + s + ":getHost()=" + si.getHost());
                LOG.info("services:" + s + ":getPort()=" + si.getPort());
                LOG.info("services:" + s + ":getServiceId()=" + si.getServiceId());
                LOG.info("services:" + s + ":getUri()=" + si.getUri());
            }
        }*/
        String info = "Hi " + name + ", this is EurekaClient, port is " + port;
        return info;
    }

    @RequestMapping(value = "/config", method = RequestMethod.GET)
    public String config() {
        String info = "port:" + port + ",message:" + message + ",foo:" + foo;
        return info;
    }
}

最后通过Run DashBoard运行项目,

首先运行上一章节的eureka-server项目, 然后运行eureka-client的项目.

在浏览器上输入http://localhost:8761,显示如下: (我这里同时运行了config-server项目, 这个项目下一章节讲)

先在浏览器中输入http://localhost:8762/testone/test, 显示如下

port是eureka-client的端口

然后在浏览器中输入http://localhost:8762/testone/config, 显示如下

port是eureka-client的端口, message和foo是从git仓库中获取的, 是通过config-server项目获取的.

下一章节讲config-server项目的搭建.