SpringCloud-Eureka【服务案例】

  上篇文章我们介绍了Eureka的集群环境搭建，本文我们来通过Eureka作为注册中心来实现一个案例，案例结构如下

一、启动Eureka服务

  在我们部署的Eureka几点上分别指向如下命令，启动Eureka服务

./server.sh start

二、构建Provider服务

1.创建SpringBoot项目

2.修改pom文件

  添加相关依赖，注意此处添加的Eureka的依赖不需要加"-server"

<dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-config</artifactId>
            <version>1.4.5.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-eureka</artifactId>
            <version>1.4.6.RELEASE</version>
        </dependency>
    </dependencies>

    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>Dalston.SR5</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>

3.修改启动类

  在启动类的头部开启Eureka客户端的主键

4.添加配置信息

  在application.properties中添加如下的信息

spring.application.name=eureka-provider
server.port=9090

# 设置服务注册中心地址，指向另一个注册中心
eureka.client.serviceUrl.defaultZone=http://eureka1:8761/eureka/,http://eureka2:8761/eureka/

注意eureka1和eureka2我们需要在hosts文件中配置映射如下

5.添加服务

创建pojo

package com.dpb.springcloud_eureka_provider.pojo;

/**
 * @program: springcloud-eureka-provider
 * @description: UserBean
 * @author: 波波烤鸭
 * @create: 2019-05-28 17:31
 */
public class User {
    private int userid;
    private String username;
    private int userage;

    public int getUserid() {
        return userid;
    }

    public void setUserid(int userid) {
        this.userid = userid;
    }

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public int getUserage() {
        return userage;
    }

    public void setUserage(int userage) {
        this.userage = userage;
    }

    public User(int userid, String username, int userage) {
        this.userid = userid;
        this.username = username;
        this.userage = userage;
    }

    public User() {
    }
}

创建控制器

/**
 * @program: springcloud-eureka-provider
 * @description: 服务提供者
 * @author: 波波烤鸭
 * @create: 2019-05-28 17:30
 */
@RestController
public class UserController {

    @RequestMapping("/user")
    public List<User> getUsers(){
        List<User> list = new ArrayList<>();
        list.add(new User(1,"zhangsan",20));
        list.add(new User(2,"lisi",22));
        list.add(new User(3,"wangwu",20));
        return list;
    }
}

6.启动服务

  启动服务,在注册中心我们可以看到我们的服务提供者

三、构建Consumer服务

  创建服务的消费者，和提供者差不多。

1.创建项目

2.pom依赖

<dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-config</artifactId>
            <version>1.4.5.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-eureka</artifactId>
            <version>1.4.6.RELEASE</version>
        </dependency>
    </dependencies>

    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>Dalston.SR5</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>

3.启动类

4.配置文件

spring.application.name=eureka-consumer
server.port=9091
#设置服务注册中心地址，指向另一个注册中心
eureka.client.serviceUrl.defaultZone=http://eureka1:8761/eureka/,http://eureka2:8761/eureka/

5.完成服务调用

  消费者完成服务端服务的调用

service中代码

/**
 * @program: springcloud-eureka-consumer
 * @description: 用户的业务处理
 * @author: 波波烤鸭
 * @create: 2019-05-28 17:43
 */
@Service
public class UserService {

    /**
     * ribbon 负载均衡
     *    LoadBalancerClient 通过服务名称可以获取对应的服务的相关信息 ip port等
     */
    @Autowired
   private LoadBalancerClient loadBalancerClient;

    public List<User> getUsers(){
        // ServiceInstance 封装的有服务的基本信息  IP和端口等
        ServiceInstance si = this.loadBalancerClient.choose("eureka-provider");
        StringBuilder sb = new StringBuilder();
        sb.append("http://")
                .append(si.getHost())
                .append(":")
                .append(si.getPort())
                .append("/user");
        // SpringMVC RestTemplate
        RestTemplate rt = new RestTemplate();
        ParameterizedTypeReference<List<User>> type = new ParameterizedTypeReference<List<User>>() {};
        // ResponseEntity:封装了返回值的信息
        ResponseEntity<List<User>> response = rt.exchange(sb.toString(), HttpMethod.GET,null,type);
        List<User> list = response.getBody();
        return list;
    }
}

控制器代码

/**
 * @program: springcloud-eureka-consumer
 * @description: 用户控制器
 * @author: 波波烤鸭
 * @create: 2019-05-28 17:40
 */
@RestController
public class UserController {

    @Autowired
    private UserService userService;
    @RequestMapping("/consumer")
    public List<User> getUsers(){
        return this.userService.getUsers();
    }
}

6.启动服务

  启动服务后我们在eureka注册中心可以发现服务。

请求消费者的接口来获取服务提供者提供的数据。

案例成功~