一.实现原理图如下：

image

二.实现的效果：

当通过订单服务去调用会员服务A,或者调用会员服务B的时候，通过ribbon来进行实现，各占用50%的机制。

三.代码实现：

1.新建一个eurakaServer服务：

POM.xml中的依赖：

       <dependency>
         <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-eureka-server</artifactId>
            <version>1.4.5.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <!-- 添加euraka的权限校验 -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-security</artifactId>
        </dependency>

2.新增配置文件application.yml

#设置euraka-server访问时带有权限，不能直接访问
security:
  basic:
    enabled: true
  user:
    name: zzh
    password: password123

server:
  port: 8086
#设置注册显示的实例名称为eureka-server1,如果不配置显示为UNKNOWN
spring:
  application:
    name: eureka-server1
eureka:
    #关闭Eureka的自我保护功能
    server:
      enable-self-preservation: false
      #配置Eureka Server清理无效节点的时间间隔
      eviction-interval-timer-in-ms: 4000
    instance:
      hostname: localhost
      #配置鼠标点击到某个服务上显示对应的IP地址
      prefer-ip-address: true
    client:
      register-with-eureka: false
      fetch-registry: false
      healthcheck:
        enabled: true
      serviceUrl:
        defaultZone: http://zzh:password123@${eureka.instance.hostname}:${server.port}/eureka/

3.编写EurekaServer的启动类

@SpringBootApplication
@EnableEurekaServer
public class EurakaServerApplication {

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

编写完成后，启动我们的eureka的服务，然后再浏览器上进行查看，如果可以看到如下界面，代表注册中心已经起来了：

image.png

四.会员服务

1.pom依赖

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

2.配置文件的编写

server:
  port: 8088
spring:
  application:
    name: service-member
eureka:
  instance:
    prefer-ip-address: true
  client:
    register-with-eureka: true
    healthcheck:
      enabled: true
    serviceUrl:
      defaultZone: http://zzh:password123@127.0.0.1:8086/eureka/

3.编写会员服务的controller,为了展示方便，我们把对应的端口号返回给前端，方便查看。

@RestController
@RequestMapping("/member")
public class MemberController {

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

    @RequestMapping("/getAllMemberInfo")
    @ResponseBody
    public String getAllMemberInfo(){
        String str="这是会员服务A,对应的端口号为："+serverPort;
        return str;
    }

}

4.编写会员服务的启动类

@SpringBootApplication
@EnableEurekaClient
@ComponentScan(basePackages = "com.itshirui")
public class ServiceMemberApplication {

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

启动成功后，我们再看eureka的界面会发现多了一个会员服务，界面如下：

image.png

接下来，我们再启动一个会员服务，更改一下端口即可，界面如下：

image.png

五.会员服务

1.pom.xml中的配置

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

2.配置文件的编写

server:
port: 8087
spring:
application:
name: service-order
eureka:
instance:
prefer-ip-address: true
client:
register-with-eureka: true
healthcheck:
enabled: true
serviceUrl:
defaultZone: http://zzh:password123@127.0.0.1:8086/eureka/

3.编写订单服务controller

@RestController
@RequestMapping("/order")
public class OrderController {

    @Autowired
    private RestTemplate restTemplate;

    @RequestMapping("/getAllOrderInfo")
    @ResponseBody
    public String getAllOrderInfo(){
        String result = restTemplate.getForObject("http://service-member/member/getAllMemberInfo", String.class);
        return result;
    }
}

4.编写订单服务的启动类

@SpringBootApplication
@EnableEurekaClient
@ComponentScan(basePackages = "com.itshirui")
public class ServiceOrderApplication {

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


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


}

@LoadBalanced 注解表示使用负载的方式进行服务的调用。

5.测试实际效果

访问订单服务后，会出现

image.png

image.png

6.虽然测试出现了负载的效果，但是中间如果有个服务断了会出现访问出现错误的情况，虽然也负载了，但是还是会出现负载到错误的请求的页面，怎么解决呢？

下一篇文章会进行分解。