1-05、Spring Cloud Alibaba 创建服务消费者

服务消费者的创建与服务提供者大同小异，这里采用最原始的一种方式，即显示的使用 LoadBalanceClient 和 RestTemplate 结合的方式来访问

POM

创建一个工程名为 hello-spring-cloud-alibaba-nacos-consumer 的服务消费者项目，pom.xml 配置如下：

    4.0.0
    
        com.wj
        hello-spring-cloud-alibaba-dependencies
        1.0.0-SNAPSHOT
        ../hello-spring-cloud-alibaba-dependencies/pom.xml
    

    hello-spring-cloud-alibaba-consumer
    jar

    
        1.8
    

    
        
        
            org.springframework.boot
            spring-boot-starter-web
        
        
            org.springframework.boot
            spring-boot-starter-actuator
        
        
            org.springframework.boot
            spring-boot-starter-test
            test
        
        

        
        
            com.alibaba.cloud
            spring-cloud-starter-alibaba-nacos-discovery
        
        
            com.alibaba.cloud
            spring-cloud-starter-alibaba-nacos-config
        
        
    

    
        
            
                org.springframework.boot
                spring-boot-maven-plugin
                
                    com.wj.hello.spring.cloud.alibaba.nacos.consumer.NacosConsumerApplication
                
            
        
    

Application

package com.wj.hello.spring.cloud.alibaba.nacos.consumer.NacosConsumerApplication;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;

@SpringBootApplication
@EnableDiscoveryClient
public class NacosConsumerApplication {
    public static void main(String[] args) {
        SpringApplication.run(NacosConsumerApplication.class, args);
    }
}

Configuration

创建一个名为 NacosConsumerConfiguration 的 Java 配置类，主要作用是为了注入 RestTemplate

package com.wj.hello.spring.cloud.alibaba.nacos.consumer.config;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.client.RestTemplate;

@Configuration
public class NacosConsumerConfiguration {

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

Controller

创建一个名为 NacosConsumerController 测试用的 Controller

package com.wj.hello.spring.cloud.alibaba.nacos.consumer.controller;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.cloud.client.ServiceInstance;
import org.springframework.cloud.client.loadbalancer.LoadBalancerClient;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.client.RestTemplate;

@RestController
public class NacosConsumerController {

    @Autowired
    private LoadBalancerClient loadBalancerClient;

    @Autowired
    private RestTemplate restTemplate;

    @Value("${spring.application.name}")
    private String appName;

    @GetMapping(value = "/echo/app/name")
    public String echo() {
        //使用 LoadBalanceClient 和 RestTemplate 结合的方式来访问
        ServiceInstance serviceInstance = loadBalancerClient.choose("nacos-provider");
        String url = String.format("http://%s:%s/echo/%s", serviceInstance.getHost(), serviceInstance.getPort(), appName);
        return restTemplate.getForObject(url, String.class);
    }
}

application.yml

spring:
  application:
    name: nacos-consumer
  cloud:
    nacos:
      discovery:
        server-addr: 127.0.0.1:8848

server:
  port: 9091

management:
  endpoints:
    web:
      exposure:
        include: "*"

启动工程

通过浏览器访问 http://localhost:8848/nacos，即 Nacos Server 网址

你会发现多了一个名为 nacos-consumer 的服务

这时打开 http://localhost:9091/echo/app/name ，你会在浏览器上看到：

Hello Nacos Discovery nacos-consumer

服务的端点检查

通过浏览器访问 http://localhost:9091/actuator/nacos-discovery 你会在浏览器上看到：