IDEA 创建 Java 项目 负载均衡 获取 Nacos 服务地址
一、创建 SpringCloud 工程
创建 SpringCloud 工程 教程
二、引入 Nacos 注册中心配置中心
引入 Nacos 注册中心配置中心教程
三、开发下单功能之创建实体类
四、开发下单功能之查询商品信息接口
五、开发下单功能之测试负载均衡
六、开发下单功能之订单服务调用商品服务
七、源码
Order.java
packageyang.junbo.bean.order;importlombok.Data;importyang.junbo.bean.product.Product;importjava.math.BigDecimal;importjava.util.List;@DatapublicclassOrder{privateLongid;privateBigDecimaltotalAmount;privateLonguserId;privateStringnickName;privateStringaddress;privateList<Product>productList;}Product.java
packageyang.junbo.bean.product;importlombok.Data;importjava.math.BigDecimal;/** * ClassName: Product * Package: yang.junbo.product.bean * Description: * * @Author 杨钧博 * @Create 2026/6/17 8:52 * @Version 1.0 */@DatapublicclassProduct{privateLongid;privateBigDecimalprice;privateStringproductName;privateintnum;}OrderController.java
packageyang.junbo.order.controller;importorg.springframework.beans.factory.annotation.Autowired;importorg.springframework.stereotype.Service;importorg.springframework.web.bind.annotation.GetMapping;importorg.springframework.web.bind.annotation.RequestParam;importorg.springframework.web.bind.annotation.RestController;importyang.junbo.bean.order.Order;importyang.junbo.order.service.OrderService;/** * ClassName: OrderController * Package: yang.junbo.order.controller * Description: * * @Author 杨钧博 * @Create 2026/6/17 9:13 * @Version 1.0 */@RestControllerpublicclassOrderController{@AutowiredprivateOrderServiceorderService;/** * 创建订单 * @param userId * @param productId * @return */@GetMapping("/create")publicOrdercreate(@RequestParam("userId")LonguserId,@RequestParam("productId")LongproductId){Orderorder=orderService.createOrder(productId,userId);returnorder;}}OrderServiceImpl.java
packageyang.junbo.order.service.impl;importlombok.extern.slf4j.Slf4j;importorg.springframework.beans.factory.annotation.Autowired;importorg.springframework.cloud.client.ServiceInstance;importorg.springframework.cloud.client.discovery.DiscoveryClient;importorg.springframework.cloud.client.loadbalancer.LoadBalancerClient;importorg.springframework.stereotype.Service;importorg.springframework.web.client.RestTemplate;importyang.junbo.bean.order.Order;importyang.junbo.order.service.OrderService;importyang.junbo.bean.product.Product;importjava.math.BigDecimal;importjava.util.Arrays;importjava.util.List;/** * ClassName: OrderSerciveImpl * Package: yang.junbo.order.service.impl * Description: * * @Author 杨钧博 * @Create 2026/6/17 9:14 * @Version 1.0 */@Slf4j@ServicepublicclassOrderSerciveImplimplementsOrderService{@AutowiredprivateDiscoveryClientdiscoveryClient;@AutowiredprivateRestTemplaterestTemplate;@AutowiredprivateLoadBalancerClientloadBalancerClient;/** * 创建订单 * @param productId * @param userId * @return */@OverridepublicOrdercreateOrder(LongproductId,LonguserId){Productproduct=getProductFromRemoteWithLoadBalanceAnnotation(productId);Orderorder=newOrder();order.setId(1L);order.setTotalAmount(product.getPrice().multiply(newBigDecimal(product.getNum())));order.setUserId(userId);order.setNickName("连杰李");order.setAddress("北京");order.setProductList(Arrays.asList(product));returnorder;}// 进阶3：基于注解的负载均衡privateProductgetProductFromRemoteWithLoadBalanceAnnotation(LongproductId){Stringurl="http://service-product/product/"+productId;//2、给远程发送请求； service-product 会被动态替换Productproduct=restTemplate.getForObject(url,Product.class);returnproduct;}privateProductgetProductFromRemote(LongproductId){//1、获取到商品服务所在的所有机器IP+portList<ServiceInstance>instances=discoveryClient.getInstances("service-product");ServiceInstanceinstance=instances.get(0);//远程URLStringurl="http://"+instance.getHost()+":"+instance.getPort()+"/product/"+productId;log.info("远程请求：{}",url);//2、给远程发送请求Productproduct=restTemplate.getForObject(url,Product.class);returnproduct;}// 进阶2：完成负载均衡发送请求privateProductgetProductFromRemoteWithLoadBalance(LongproductId){//1、获取到商品服务所在的所有机器IP+portServiceInstancechoose=loadBalancerClient.choose("service-product");//远程URLStringurl="http://"+choose.getHost()+":"+choose.getPort()+"/product/"+productId;log.info("远程请求：{}",url);//2、给远程发送请求Productproduct=restTemplate.getForObject(url,Product.class);returnproduct;}}OrderServiceConfig.java
packageyang.junbo.order.config;importorg.springframework.cloud.client.loadbalancer.LoadBalanced;importorg.springframework.context.annotation.Bean;importorg.springframework.context.annotation.Configuration;importorg.springframework.web.client.RestTemplate;/** * ClassName: OrderServiceConfig * Package: yang.junbo.order.config * Description: * * @Author 杨钧博 * @Create 2026/6/17 9:48 * @Version 1.0 */@ConfigurationpublicclassOrderServiceConfig{@Bean@LoadBalancedpublicRestTemplaterestTemplate(){returnnewRestTemplate();}}ProductController.java
packageyang.junbo.product.controller;importlombok.extern.slf4j.Slf4j;importorg.springframework.beans.factory.annotation.Autowired;importorg.springframework.web.bind.annotation.GetMapping;importorg.springframework.web.bind.annotation.PathVariable;importorg.springframework.web.bind.annotation.RestController;importyang.junbo.bean.product.Product;importyang.junbo.product.service.ProductService;/** * ClassName: ProductController * Package: yang.junbo.product.controller * Description: * * @Author 杨钧博 * @Create 2026/6/17 8:53 * @Version 1.0 */@Slf4j@RestControllerpublicclassProductController{@AutowiredprivateProductServiceproductService;/** * 获取商品信息 * @param productId * @return */@GetMapping("/product/{id}")publicProductgetProduct(@PathVariable("id")LongproductId){log.info("查询商品信息"+System.currentTimeMillis());Productproduct=productService.getProduct(productId);returnproduct;}}ProductServiceImpl.java
packageyang.junbo.product.service.impl;importorg.springframework.stereotype.Service;importyang.junbo.bean.product.Product;importyang.junbo.product.service.ProductService;importjava.math.BigDecimal;/** * ClassName: ProductServiceImpl * Package: yang.junbo.product.service.impl * Description: * * @Author 杨钧博 * @Create 2026/6/17 8:54 * @Version 1.0 */@ServicepublicclassProductServiceImplimplementsProductService{/** * 获取商品信息 * @param productId * @return */@OverridepublicProductgetProduct(LongproductId){Productproduct=newProduct();product.setId(Long.valueOf("1"));product.setPrice(newBigDecimal(8000));product.setProductName("iPhone 17");product.setNum(1);returnproduct;}}LoadBalancerTest.java
packageyang.junbo.order;importorg.junit.jupiter.api.Test;importorg.springframework.beans.factory.annotation.Autowired;importorg.springframework.boot.test.context.SpringBootTest;importorg.springframework.cloud.client.ServiceInstance;importorg.springframework.cloud.client.loadbalancer.LoadBalancerClient;/** * ClassName: LoadBalancerTest * Package: yang.junbo.order * Description: * * @Author 杨钧博 * @Create 2026/6/17 10:47 * @Version 1.0 */@SpringBootTestpublicclassLoadBalancerTest{@AutowiredprivateLoadBalancerClientloadBalancerClient;@Testvoidtest(){ServiceInstancechoose=loadBalancerClient.choose("service-product");System.out.println("choose = "+choose.getHost()+"："+choose.getPort());choose=loadBalancerClient.choose("service-product");System.out.println("choose = "+choose.getHost()+"："+choose.getPort());choose=loadBalancerClient.choose("service-product");System.out.println("choose = "+choose.getHost()+"："+choose.getPort());choose=loadBalancerClient.choose("service-product");System.out.println("choose = "+choose.getHost()+"："+choose.getPort());choose=loadBalancerClient.choose("service-product");System.out.println("choose = "+choose.getHost()+"："+choose.getPort());}}
