服务发现Discovery

对于注册进eureka里面的微服务，可以通过服务发现来获得该服务的信息

1、修改cloud-provider-payment8001的controller


import com.my.springcloud.utils.RestResponse;
import com.my.springcloud.entities.Payment;
import com.my.springcloud.service.PaymentService;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.cloud.client.ServiceInstance;
import org.springframework.cloud.client.discovery.DiscoveryClient;
import org.springframework.web.bind.annotation.*;

import javax.annotation.Resource;
import java.util.List;
import java.util.concurrent.TimeUnit;

@RestController
@Slf4j
public class PaymentController {

    @Resource
    private DiscoveryClient discoveryClient;

    /**
     * Discovery服务发现
     */
    @GetMapping(value = "/payment/discovery")
    public Object discovery() {

        // 第一种方式：获取所有服务
        List<String> services = discoveryClient.getServices();
        // 遍历每一个服务
        for (String element : services) {
            log.info("*****element: " + element);
        }
        // 第二种方式：获取键名下的所有服务
        List<ServiceInstance> instances = discoveryClient.getInstances("CLOUD-PAYMENT-SERVICE");
        // 遍历每一个服务
        for (ServiceInstance instance : instances) {
            log.info(instance.getServiceId() + "\t" + instance.getHost() + "\t" + instance.getPort() + "\t" + instance.getUri());
        }
        return this.discoveryClient;
    }
  }

2、主启动类上加上@EnableDiscoveryClient注解

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

@SpringBootApplication
@EnableEurekaClient   //Eureka客户端
@EnableDiscoveryClient //启动服务发现
public class PaymentMain8001 {

    public static void main(String[] args) {
        SpringApplication.run(PaymentMain8001.class, args);
    }
}