负载均衡API测试

1.引入负载均衡依赖(services模块)

<!--负载均衡-->
<dependency><groupId>org.springframework.cloud</groupId><artifactId>spring-cloud-starter-loadbalancer</artifactId>
</dependency>

2,测试类

package com.order;import com.cx.order.OrderMainApplication;
import jakarta.annotation.Resource;
import org.junit.jupiter.api.Test;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.cloud.client.ServiceInstance;
import org.springframework.cloud.client.loadbalancer.LoadBalancerClient;/*** @author Jiang* @date 2025/11/15*/
@SpringBootTest(classes = {OrderMainApplication.class})
public class OrderApplicationTest {@ResourceLoadBalancerClient loadBalancerClient;@Testpublic void test() {ServiceInstance choose = loadBalancerClient.choose("service-product");System.out.println("choose.getHost()+choose.getPort() = " + choose.getHost() + ":" + choose.getPort());choose = loadBalancerClient.choose("service-product");System.out.println("choose.getHost()+choose.getPort() = " + choose.getHost() + ":" + choose.getPort());choose = loadBalancerClient.choose("service-product");System.out.println("choose.getHost()+choose.getPort() = " + choose.getHost() + ":" + choose.getPort());choose = loadBalancerClient.choose("service-product");System.out.println("choose.getHost()+choose.getPort() = " + choose.getHost() + ":" + choose.getPort());choose = loadBalancerClient.choose("service-product");System.out.println("choose.getHost()+choose.getPort() = " + choose.getHost() + ":" + choose.getPort());}}

3.使用负载均衡的方式进行远程调用

package com.cx.order.service.impl;import com.cx.Order;
import com.cx.Product;
import com.cx.order.service.OrderService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.cloud.client.ServiceInstance;
import org.springframework.cloud.client.discovery.DiscoveryClient;
import org.springframework.cloud.client.loadbalancer.LoadBalancerClient;
import org.springframework.stereotype.Service;
import org.springframework.web.client.RestTemplate;import java.math.BigDecimal;
import java.util.Arrays;
import java.util.List;/*** @author Jiang* @date 2025/11/7*/
@Service
public class OrderServiceImpl implements OrderService {@AutowiredDiscoveryClient discoveryClient;@AutowiredRestTemplate restTemplate;@AutowiredLoadBalancerClient loadBalancerClient;@Overridepublic Order createOrder(Long userId, Long productId) {Product product = getProductFromRemote(productId);Order order = new Order();order.setId(1L);// 总金额=价格*数量BigDecimal price = product.getPrice();//价格int num = product.getNum();//数量order.setTotalAmount(price.multiply(new BigDecimal(num)));//总价order.setUserId(userId);order.setNickName("张三");order.setAddress("火星");// 远程查询商品列表order.setProductList(Arrays.asList(product));return order;}//远程调用获取商品信息public Product getProductFromRemote(Long productId) {//1、获取到商品服务所在的所有机器IP+portList<ServiceInstance> instances = discoveryClient.getInstances("service-product");ServiceInstance instance = instances.get(0);//远程URLString url = "http://" + instance.getHost() + ":" + instance.getPort() + "/productId/" + productId;//2、给远程发送请求return restTemplate.getForObject(url, Product.class);}//负载均衡public Product getProductFromRemoteWithLoadBalance(Long productId) {//1、获取到商品服务所在的所有机器IP+portServiceInstance choose = loadBalancerClient.choose("service-product");//远程URLString url = "http://" + choose.getHost() + ":" + choose.getPort() + "/productId/" + productId;//2、给远程发送请求Product product = restTemplate.getForObject(url, Product.class);return product;}}

总结:discoveryClient返回的是服务列表,loadBalancerClient返回的是单个实例它会根据配置的负载均衡算法从可用实例中挑选一个合适的实例以达到负载均衡的目的