Spring Cloud Alibaba-Nacos-创建服务消费者

概述

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：

1. <?xml version="1.0" encoding="UTF-8"?>
2. <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
3. xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
4. <modelVersion>4.0.0</modelVersion>
6. <parent>
7. <groupId>cn.dandelioncloud</groupId>
8. <artifactId>hello-spring-cloud-alibaba-dependencies</artifactId>
9. <version>1.0.0-SNAPSHOT</version>
10. <relativePath>../hello-spring-cloud-alibaba-dependencies/pom.xml</relativePath>
11. </parent>
13. <artifactId>hello-spring-cloud-alibaba-nacos-consumer</artifactId>
14. <packaging>jar</packaging>
16. <name>hello-spring-cloud-alibaba-nacos-consumer</name>
17. <url>http://www.dandelioncloud.cn</url>
18. <inceptionYear>2018-Now</inceptionYear>
20. <dependencies>
21. <!-- Spring Boot Begin -->
22. <dependency>
23. <groupId>org.springframework.boot</groupId>
24. <artifactId>spring-boot-starter-web</artifactId>
25. </dependency>
26. <dependency>
27. <groupId>org.springframework.boot</groupId>
28. <artifactId>spring-boot-starter-actuator</artifactId>
29. </dependency>
30. <dependency>
31. <groupId>org.springframework.boot</groupId>
32. <artifactId>spring-boot-starter-test</artifactId>
33. <scope>test</scope>
34. </dependency>
35. <!-- Spring Boot End -->
37. <!-- Spring Cloud Begin -->
38. <dependency>
39. <groupId>org.springframework.cloud</groupId>
40. <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
41. </dependency>
42. <!-- Spring Cloud End -->
43. </dependencies>
45. <build>
46. <plugins>
47. <plugin>
48. <groupId>org.springframework.boot</groupId>
49. <artifactId>spring-boot-maven-plugin</artifactId>
50. <configuration>
51. <mainClass>cn.dandelioncloud.hello.spring.cloud.alibaba.nacos.consumer.NacosConsumerApplication</mainClass>
52. </configuration>
53. </plugin>
54. </plugins>
55. </build>
56. </project>

Application

1. package cn.dandelioncloud.hello.spring.cloud.alibaba.nacos.consumer;
3. import org.springframework.boot.SpringApplication;
4. import org.springframework.boot.autoconfigure.SpringBootApplication;
5. import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
7. @SpringBootApplication
8. @EnableDiscoveryClient
9. public class NacosConsumerApplication {
10. public static void main(String[] args) {
11. SpringApplication.run(NacosConsumerApplication.class, args);
12. }
13. }

Configuration

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

1. package cn.dandelioncloud.hello.spring.cloud.alibaba.nacos.consumer.config;
3. import org.springframework.context.annotation.Bean;
4. import org.springframework.context.annotation.Configuration;
5. import org.springframework.web.client.RestTemplate;
7. @Configuration
8. public class NacosConsumerConfiguration {
10. @Bean
11. public RestTemplate restTemplate() {
12. return new RestTemplate();
13. }
14. }

Controller

创建一个名为 NacosConsumerController 测试用的 Controller

1. package cn.dandelioncloud.hello.spring.cloud.alibaba.nacos.consumer.controller;
3. import org.springframework.beans.factory.annotation.Autowired;
4. import org.springframework.beans.factory.annotation.Value;
5. import org.springframework.cloud.client.ServiceInstance;
6. import org.springframework.cloud.client.loadbalancer.LoadBalancerClient;
7. import org.springframework.web.bind.annotation.GetMapping;
8. import org.springframework.web.bind.annotation.RestController;
9. import org.springframework.web.client.RestTemplate;
11. @RestController
12. public class NacosConsumerController {
14. @Autowired
15. private LoadBalancerClient loadBalancerClient;
17. @Autowired
18. private RestTemplate restTemplate;
20. @Value("${spring.application.name}")
21. private String appName;
23. @GetMapping(value = "/echo/app/name")
24. public String echo() {
25. //使用 LoadBalanceClient 和 RestTemplate 结合的方式来访问
26. ServiceInstance serviceInstance = loadBalancerClient.choose("nacos-provider");
27. String url = String.format("http://%s:%s/echo/%s", serviceInstance.getHost(), serviceInstance.getPort(), appName);
28. return restTemplate.getForObject(url, String.class);
29. }
30. }

application.yml

1. spring:
2. application:
3. name: nacos-consumer
4. cloud:
5. nacos:
6. discovery:
7. server-addr: 127.0.0.1:8848
9. server:
10. port: 9091
12. management:
13. endpoints:
14. web:
15. exposure:
16. 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： 

1. 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：