每天学点SpringCloud（二）：服务注册与发现Eureka

相信看过 每天学点SpringCloud（一）：简单服务提供者消费者调用的同学都发现了，在最后消费者调用提供者的时候把提供者的地址硬编码在了代码中，这样的方式肯定是不行的，今天，我们就是要Eureka来解决这个问题

创建Eureka服务

1.我们在原先项目的基础上再新建一个项目cloud-demo-eureka

此项目的依赖为

<?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"&gt;
<parent>
<artifactId>spring-cloud-demo</artifactId>
<groupId>cn.org.zhixiang</groupId>
<version>0.0.1-SNAPSHOT</version>
</parent>
<modelVersion>4.0.0</modelVersion>

<artifactId>cloud-demo-eureka</artifactId>

<properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
    <java.version>1.8</java.version>
</properties>
<dependencies>
    <dependency>
        <groupId>org.springframework.cloud</groupId>
        <!--注意此处的依赖是SpringBoot2.0以后专用的，如果您使用的SpringBoot版本低于2.0请使用spring-cloud-starter-eureka-server-->
        <artifactId>spring-cloud-starter-netflix-eureka-server</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-security</artifactId>
    </dependency>
</dependencies>

<build>
    <plugins>
        <plugin>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-maven-plugin</artifactId>
        </plugin>
    </plugins>
</build>

</project>

2.创建application.yml

spring:
application:
name: eureka-server
#开启权限认证
security:
basic:
enabled: true
user:
name: root
password: root

server:
host: localhost
port: 8761
eureka:
client:
#此项目不作为客户端注册
register-with-eureka: false
fetch-registry: false
service-url:
#开启权限验证后Eureka地址为 用户名：密码@地址：端口号，如未开启权限验证则直接使用 地址：端口号
defaultZone: http://${spring.security.user.name}:${spring.security.user.password}@${server.host}:${server.port}/eureka

3.创建cn.org.zhixiang包，在此包下创建CloudDemoEureApplication启动类

package cn.org.zhixiang;

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

@SpringBootApplicationbr/>@EnableEurekaServer
public class CloudDemoEureApplication {
public static void main(String[] args) {
SpringApplication.run(CloudDemoEureApplication.class, args);
}
}

4.如果您开启了权限验证并且SpringBoot版本为2.0以上的话还需要一个操作，如果不是此布可以忽略

因为2.0默认开启了csrf，如果我们现在直接启动Eureka服务的话客户端是注册不上的，所以需要把csrf关闭

在cn.org.zhixiang包下新建security包，新建WebSecurityConfigurer类

@EnableWebSecurity
public class WebSecurityConfigurer extends WebSecurityConfigurerAdapter {br/>@Override
protected void configure(HttpSecurity http) throws Exception {
http.csrf().disable();
super.configure(http);
}
}

5.在CloudDemoEureApplication启动类中启动Eureka服务，浏览器访问http://localhost:8761/eureka，输入用户名root和密码root登陆Eureka后Eureka服务创建成功。

修改服务提供者

1.在原先的cloud-demo-provider项目中添加Eureka依赖

<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-netflix-eureka-server</artifactId>
</dependency>

2.修改application.yml，增加以下配置

eurekaServer:
host: localhost
port: 8761
user: root
password: root

eureka:
client:
#将此项目注册到Eureka服务
register-with-eureka: true
service-url:
defaultZone: http://${eurekaServer.user}:${eurekaServer.password}@${eurekaServer.host}:${eurekaServer.port}/eureka

@SpringBootApplicationbr/>@EnableEurekaClient
public class CloudDemoConsumerApplication {br/>@Bean
@LoadBalanced//开启负载均衡
public RestTemplate restTemplate(){
return new RestTemplate();
}
public static void main(String[] args) {
SpringApplication.run(CloudDemoConsumerApplication.class, args);
}
}

@RestControllerbr/>@RequestMapping("/user")
public class UserController {

@Autowired
private RestTemplate restTemplate;

@GetMapping("/getUser/{id}")
public User getUser(@PathVariable Long id){
     return restTemplate.getForObject("http://provider-demo/user/getUser/"+id,User.class);
}

GitHub：https://github.com/2388386839/spring-cloud-demo

码云：https://gitee.com/zhixiang_blog/apring-cloud-demo