负载均衡API测试

1.引入负载均衡依赖(services模块)

html 复制代码

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

2,测试类

java 复制代码

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 {

    @Resource
    LoadBalancerClient loadBalancerClient;

    @Test
    public 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

java 复制代码

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 {
    @Autowired
    DiscoveryClient discoveryClient;

    @Autowired
    RestTemplate restTemplate;

    @Autowired
    LoadBalancerClient loadBalancerClient;
    @Override
    public 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+port
        List<ServiceInstance> instances = discoveryClient.getInstances("service-product");
        ServiceInstance instance = instances.get(0);
        //远程URL
        String 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+port
        ServiceInstance choose = loadBalancerClient.choose("service-product");
        //远程URL
        String 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