Eureka 查找服务——Eureka的使用（三）

在Server项目中

• 新建Controller

package com.basil.controller;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.cloud.client.ServiceInstance;
import org.springframework.cloud.client.discovery.DiscoveryClient;
import org.springframework.util.CollectionUtils;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.client.RestTemplate;
import java.util.List;


/**
 * @Author: chuan.bai
 * @Description
 * @Date: Created on 10:29 2018/12/25
 * @Modified By:
 */
@RestController
public class TestController {

    @Autowired
    private RestTemplate restTemplate;

    @Autowired
    private DiscoveryClient discoveryClient;


    /**
     * 获取eureka-client服务信息
     * @return
     */
    @GetMapping(value = "getEurekaClientInstance")
    public List<ServiceInstance> getEurekaClientInstance() {
        List<ServiceInstance> list=discoveryClient.getInstances("eureka-client");
        return list;
    }

    /**
     * 获取所有的服务
     * @return
     */
    @GetMapping(value = "getServiceMetaData")
    public String getServiceMetaData(){
        StringBuilder buf = new StringBuilder();
        List<String> serviceIds = discoveryClient.getServices();
        System.out.println("serviceId"+serviceIds);
        if(!CollectionUtils.isEmpty(serviceIds)){
            for(String s : serviceIds){
                System.out.println("serviceId:" + s);
                List<ServiceInstance> serviceInstances =  discoveryClient.getInstances(s);
                if(!CollectionUtils.isEmpty(serviceInstances)){
                    for(ServiceInstance si:serviceInstances){
                        buf.append("["+si.getServiceId() +" host=" +si.getHost()+" port="+si.getPort()+" uri="+si.getUri()+"]");
                    }
                }else{
                    buf.append("no service.");
                }
            }
        }


        return buf.toString();

    }


}

• 启动项

package com.basil;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.web.client.RestTemplateBuilder;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
import org.springframework.context.annotation.Bean;
import org.springframework.web.client.RestTemplate;

/**
 * @author Basil
 */
@SpringBootApplication
@EnableDiscoveryClient
public class EurekaClientApplication {

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


    @Autowired
    private RestTemplateBuilder builder;

    // 使用RestTemplateBuilder来实例化RestTemplate对象，spring默认已经注入了RestTemplateBuilder实例
    @Bean
    public RestTemplate restTemplate() {
        return builder.build();
    }


}

• 可以在配置文件中 增加自定义数据 eureka.instance.metadata-map.my-metadata

server:
  port: 9092
spring:
  application:
    name: eureka-client
eureka:
  instance:
    hostname: localhost
    # 使用IP注册
    preferIpAddress: true
    # 心跳间隔
    lease-renewal-interval-in-seconds: 3
    # 服务失效时间： 如果多久没有收到请求，则可以删除服务
    lease-expiration-duration-in-seconds: 7
    metadata-map :
      my-metadata: aa:cc
  client:
    # 关闭eureka client
    # enabled: false
    # 注册自身到eureka服务器
    register-with-eureka: true
    # 表示是否从eureka服务器获取注册信息
    fetch-registry: false
    # 客户端从Eureka Server集群里更新Eureka Server信息的频率
    eureka-service-url-poll-interval-seconds: 60
    # 定义从注册中心获取注册服务的信息
    registry-fetch-interval-seconds: 5
    # 设置eureka服务器所在的地址，查询服务和注册服务都需要依赖这个地址
    service-url:
      defaultZone: http://server1:8771/eureka/,http://server2:8772/eureka/,http://server3:8773/eureka/

• 访问页面 ：http://localhost:8771/getEurekaClientInstance

image.png

访问页面：http://localhost:8771/eureka/apps 查看metadata

metadata