服务发现（Discovery）基于Eureka注册中心

<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-starter-eureka</artifactId>
    <version>1.4.6.RELEASE</version>
</dependency>
<!--完善监控信息-->
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-actuator</artifactId>
</dependency>

# Eureka 配置
eureka:
  client:
    service-url:
      #这里模拟的是集群
      defaultZone: http://eureka7001.com:7001/eureka/,http://eureka7002.com:7002/eureka/,http://eureka7003.com:7003/eureka/
      
  instance:
    instance-id: springcloud-provider-dept8001 # 修改 eureka 上的默认描述信息
    prefer-ip-address: true #true 显示服务的ip

# info 配置
info:
 app.name: springcloud-provider
 commony.name: xxxx.com

    @Resource
    private DiscoveryClient discoveryClient;

    @GetMapping(value = "/payment/discovery")
    public Object discovery() {
        List<String> services = discoveryClient.getServices();

        for (String element : services) {
            log.info("******element：" + element);
        }

        List<ServiceInstance> instances = discoveryClient.getInstances("CLOUD-PAYMENT-SERVICE");
        for (ServiceInstance instance : instances) {
            log.info(instance.getServiceId() + "\t" + instance.getInstanceId() + "\t" + instance.getHost() + "\t" + instance.getPort() +
                    "\t" +
                    instance.getUri
                    ());
        }
        return this.discoveryClient;
    }