SpringCloud学习笔记-Eureka的服务拉取

假设是OrderService里面拉取Eureka的服务之一User Service

1.依然需要在该服务里面引入依赖

<dependency><groupId>org.springframework.cloud</groupId><artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
</dependency>

2.在OrderService里面需要有如下配置

spring:application:name: orderservice #添加的微服务的服务名称,把名字为userservice的微服务加入到注册名单中
eureka:client:service-url:defaultZone: http://localhost:10086/eureka   #eureka的地址信息

3.修改URL和OrderService中添加@Load Balanced注解

1.修改URL

package cn.itcast.eureka.order.service;import cn.itcast.eureka.order.mapper.OrderMapper;
import cn.itcast.eureka.order.pojo.Order;
import cn.itcast.eureka.order.pojo.User;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.web.client.RestTemplate;import javax.annotation.Resource;@Service
public class OrderService {@Autowiredprivate OrderMapper orderMapper;@Autowiredprivate RestTemplate restTemplate;public Order queryOrderById(Long orderId) {// 1.查询订单Order order = orderMapper.findById(orderId);String url = "http://userservice/user/" + order.getUserId();//OrderService里面拉取Eureka的服务之一User Service//把原来的http://localhost:8080/user/变成了http://userservice/user/User user = restTemplate.getForObject(url, User.class);order.setUser(user);// 4.返回return order;}
}

2.OrderService中添加@Load Balanced注解

package cn.itcast.eureka.order;import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.loadbalancer.LoadBalanced;
import org.springframework.context.annotation.Bean;
import org.springframework.web.client.RestTemplate;@MapperScan("cn.itcast")
@SpringBootApplication
public class OrderApplication {@Bean @LoadBalancedpublic RestTemplate restTemplate(){return new RestTemplate();}public static void main(String[] args) {SpringApplication.run(OrderApplication.class, args);}}

通过服务名称获取IP地址的原理如下图所示,其中由于WIndows电脑的设置,原来的IP地址被替换成为了电脑名称LAPTOPXXX,其实还是可以获取到具体的IP