Nacos注册/配置中心

一、Nacos 注册/配置中心

1. 服务注册

• 引入依赖

<dependency><groupId>com.alibaba.cloud</groupId><artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId></dependency>

• 整合配置

spring.application.name=service-order server.port=8000 spring.cloud.nacos.discovery.server-addr=127.0.0.1:8848

2. 服务发现

1. 开启服务发现

@EnableDiscoveryClient//开启服务发现功能@SpringBootApplicationpublicclassProductMainApplication{publicstaticvoidmain(String[]args){SpringApplication.run(ProductMainApplication.class,args);}}

2. 测试服务发现
   • 这里discoveryClient和nacosServiceDiscovery效果一样

@SpringBootTestpublicclassDiscoveryTest{@AutowiredDiscoveryClientdiscoveryClient;@AutowiredNacosServiceDiscoverynacosServiceDiscovery;@TestvoiddiscoveryClientTest(){//获取所有服务for(Stringservice:discoveryClient.getServices()){System.out.println("service = "+service);//获取ip+port//获取所有实例List<ServiceInstance>instances=discoveryClient.getInstances(service);for(ServiceInstanceinstance:instances){System.out.println("ip; "+instance.getHost()+"; "+"port = "+instance.getPort());}}}@TestvoidnacosServiceDiscoveryTest()throwsNacosException{for(Stringservice:nacosServiceDiscovery.getServices()){System.out.println("service = "+service);//获取ip+porttry{List<ServiceInstance>instances=nacosServiceDiscovery.getInstances(service);for(ServiceInstanceinstance:instances){System.out.println("ip; "+instance.getHost()+"; "+"port = "+instance.getPort());}}catch(Exceptione){e.printStackTrace();}}}}

3. 远程调用

1. 配置RestTemplate
   • RestTemplate是Spring提供的组件，发送请求

   @Configuration

public class ProductServiceConfig {

@Bean public RestTemplate restTemplate(){ return new RestTemplate(); }

}

```java /** * 远程查询商品信息 * @param productId * @return */ private Product getProductFromRemote(Long productId){ //1. 获取商品服务所在的所有机器IP+port List<ServiceInstance> instances = discoveryClient.getInstances("service-product"); ServiceInstance serviceInstance = instances.get(1); //远程url String url = "http://"+serviceInstance.getHost()+":"+serviceInstance.getPort()+"/product/"+productId; log.info("url = " + url); //给远程发送请求 Product product = restTemplate.getForObject(url, Product.class); return product; }

4. 负载均衡

• RestTemplate添加@LoadBalanced

@ConfigurationpublicclassProductServiceConfig{@Bean@LoadBalancedpublicRestTemplaterestTemplate(){returnnewRestTemplate();}}

• 直接拼写

  /**

• 基于注解的负载均衡远程查询商品信息
• @param productId
• @return
  */

private Product getProductFromRemoteWithLoadBalancerAnnotation(Long productId){
// 进阶 3 ：基于注解的负载均衡
String url = “http://service-product/product/”+productId;
//给远程发送请求 service-product 会被动态替换
Product product = restTemplate.getForObject(url, Product.class);
return product;
}