Spring Cloud Alibaba | Nacos服务注册与发现

Springboot: 2.1.6.RELEASE

SpringCloud: Greenwich.SR1

如无特殊说明，本系列文章全采用以上版本

Spring Cloud Alibaba | Nacos服务注册与发现

上一篇《Spring Cloud Alibaba | Nacos服务中心初探》我们聊了什么是Nacos以及Nacos如何搭建，这一篇我们接着聊Nacos如何简单使用。

首先，Nacos是一个服务注册和服务发现的注册中心，在Spring Cloud中，可以替代Eureka的功能，我们先聊一下Nacos如何和Spring Cloud集成做一个注册中心。

整体流程为：

先启动注册中心Nacos
启动服务的提供者将提供服务，并将服务注册到注册中心Nacos上
启动服务的消费者，在Nacos中找到服务并完成消费

1. 服务提供者

新建一个producer的项目，项目依赖如下：

1.1 pom.xml项目依赖

<?xml version="1.0" encoding="UTF-8"?>

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">

	<modelVersion>4.0.0</modelVersion>

	<parent>

		<groupId>org.springframework.boot</groupId>

		<artifactId>spring-boot-starter-parent</artifactId>

		<version>2.1.6.RELEASE</version>

		<relativePath/> <!-- lookup parent from repository -->

	</parent>

	<groupId>com.springcloud</groupId>

	<artifactId>producer</artifactId>

	<version>0.0.1-SNAPSHOT</version>

	<name>producer</name>

	<description>Demo project for Spring Boot</description>

	<properties>

		<java.version>1.8</java.version>

	</properties>

	<dependencies>

		<dependency>

			<groupId>org.springframework.boot</groupId>

			<artifactId>spring-boot-starter-web</artifactId>

		</dependency>

		<dependency>

			<groupId>org.springframework.cloud</groupId>

			<artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>

			<version>0.9.0.RELEASE</version>

		</dependency>

		<dependency>

			<groupId>org.springframework.boot</groupId>

			<artifactId>spring-boot-starter-test</artifactId>

			<scope>test</scope>

		</dependency>

	</dependencies>

	<build>

		<plugins>

			<plugin>

				<groupId>org.springframework.boot</groupId>

				<artifactId>spring-boot-maven-plugin</artifactId>

			</plugin>

		</plugins>

	</build>

</project>

增加Nacos的服务发现的依赖：spring-cloud-starter-alibaba-nacos-discovery，根据版本SpringCloud和SpringBoot的版本，这里我们使用0.9.0.RELEASE版本。其他版本使用请看上一篇《Spring Cloud Alibaba | Nacos服务中心初探》。

1.2 配置文件application.yml

server:

  port: 9000

spring:

  application:

    name: spring-cloud-nacos-producer

  cloud:

    nacos:

      discovery:

        server-addr: localhost:8848

1.3 启动类ProducerApplication.java

package com.springcloud.producer;

import org.springframework.boot.SpringApplication;

import org.springframework.boot.autoconfigure.SpringBootApplication;

import org.springframework.cloud.client.discovery.EnableDiscoveryClient;

@SpringBootApplication

@EnableDiscoveryClient

public class ProducerApplication {

	public static void main(String[] args) {

		SpringApplication.run(ProducerApplication.class, args);

	}

}

@EnableDiscoveryClient 注册服务至Nacos。

1.4 controller

package com.springcloud.producer.controller;

import org.springframework.web.bind.annotation.RequestMapping;

import org.springframework.web.bind.annotation.RequestParam;

import org.springframework.web.bind.annotation.RestController;

/**

 * Created with IntelliJ IDEA.

 *

 * @Date: 2019/7/14

 * @Time: 10:04

 * @email: inwsy@hotmail.com

 * Description:

 */

@RestController

public class HelloController {

    @RequestMapping("/hello")

    public String hello(@RequestParam String name) {

        return "hello "+name+"，producer is ready";

    }

}

1.5 测试

启动服务producer，在浏览器访问链接：http://localhost:9000/hello?name=nacos，可以看到页面显示hello nacos，producer is ready。

打开Nacos显示页面，可以看到服务spring-cloud-nacos-producer正常上线。

到这里，我们的服务提供者已经正常搭建完毕。

2. 服务消费者

2.1 pom.xml项目依赖

<?xml version="1.0" encoding="UTF-8"?>

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">

	<modelVersion>4.0.0</modelVersion>

	<parent>

		<groupId>org.springframework.boot</groupId>

		<artifactId>spring-boot-starter-parent</artifactId>

		<version>2.1.6.RELEASE</version>

		<relativePath/> <!-- lookup parent from repository -->

	</parent>

	<groupId>com.spring</groupId>

	<artifactId>nacos-cosumers</artifactId>

	<version>0.0.1-SNAPSHOT</version>

	<name>nacos-cosumers</name>

	<description>Demo project for Spring Boot</description>

	<properties>

		<java.version>1.8</java.version>

		<spring-cloud.version>Greenwich.SR2</spring-cloud.version>

	</properties>

	<dependencies>

		<dependency>

			<groupId>org.springframework.boot</groupId>

			<artifactId>spring-boot-starter-web</artifactId>

		</dependency>

		<dependency>

			<groupId>org.springframework.cloud</groupId>

			<artifactId>spring-cloud-starter-openfeign</artifactId>

		</dependency>

		<dependency>

			<groupId>org.springframework.cloud</groupId>

			<artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>

			<version>0.9.0.RELEASE</version>

		</dependency>

		<dependency>

			<groupId>org.springframework.boot</groupId>

			<artifactId>spring-boot-starter-test</artifactId>

			<scope>test</scope>

		</dependency>

	</dependencies>

	<dependencyManagement>

		<dependencies>

			<dependency>

				<groupId>org.springframework.cloud</groupId>

				<artifactId>spring-cloud-dependencies</artifactId>

				<version>${spring-cloud.version}</version>

				<type>pom</type>

				<scope>import</scope>

			</dependency>

		</dependencies>

	</dependencyManagement>

	<build>

		<plugins>

			<plugin>

				<groupId>org.springframework.boot</groupId>

				<artifactId>spring-boot-maven-plugin</artifactId>

			</plugin>

		</plugins>

	</build>

</project>

这里增加了spring-cloud-starter-openfeign依赖包

2.2 配置文件application.yml

server:

  port: 8080

spring:

  application:

    name: spring-cloud-nacos-consumers

  cloud:

    nacos:

      discovery:

        server-addr: localhost:8848

2.3 启动类NacosCosumersApplication.java

package com.spring.nacoscosumers;

import org.springframework.boot.SpringApplication;

import org.springframework.boot.autoconfigure.SpringBootApplication;

import org.springframework.cloud.client.discovery.EnableDiscoveryClient;

import org.springframework.cloud.openfeign.EnableFeignClients;

@SpringBootApplication

@EnableDiscoveryClient

@EnableFeignClients

public class NacosCosumersApplication {

	public static void main(String[] args) {

		SpringApplication.run(NacosCosumersApplication.class, args);

	}

}

@EnableFeignClients这个注解是声明Feign远程调用

2.4 Feign远程调用

创建一个remote接口

package com.spring.nacoscosumers.remote;

import org.springframework.cloud.openfeign.FeignClient;

import org.springframework.web.bind.annotation.RequestMapping;

import org.springframework.web.bind.annotation.RequestParam;

@FeignClient(name= "spring-cloud-nacos-producer")

public interface HelloRemote {

    @RequestMapping(value = "/hello")

    String hello(@RequestParam(value = "name") String name);

}

2.5 web层调用远程接口 Controller

package com.spring.nacoscosumers.controller;

import com.spring.nacoscosumers.remote.HelloRemote;

import org.springframework.beans.factory.annotation.Autowired;

import org.springframework.web.bind.annotation.PathVariable;

import org.springframework.web.bind.annotation.RequestMapping;

import org.springframework.web.bind.annotation.RestController;

/**

 * Created with IntelliJ IDEA.

 *

 * @Date: 2019/7/14

 * @Time: 10:24

 * @email: inwsy@hotmail.com

 * Description:

 */

@RestController

public class HelloController {

    @Autowired

    HelloRemote helloRemote;

    @RequestMapping("/hello/{name}")

    public String index(@PathVariable("name") String name) {

        return helloRemote.hello(name);

    }

}

2.6 测试

启动服务消费者nacos-consumers，打开浏览器访问链接：http://localhost:8080/hello/nacos，这时页面正常返回hello nacos，producer is ready，证明我们的已经通过Nacos作为注册中心已经正常提供了服务注册与发现。

3. 集成Gateway

上面介绍了Nacos可以和Feign集成使用，更多的情况下，我们需要和API网关来集成。

这里我们还是使用之前的服务提供者，新建一个服务网关。

这里我们使用了Gateway做演示，想使用Zuul的朋友可以作为参考，在原有Zuul+Eureka的基础上只需要更换配置和依赖包就可以，无需其他过多的修改。

3.1 pom.xml项目依赖

<?xml version="1.0" encoding="UTF-8"?>

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">

	<modelVersion>4.0.0</modelVersion>

	<parent>

		<groupId>org.springframework.boot</groupId>

		<artifactId>spring-boot-starter-parent</artifactId>

		<version>2.1.6.RELEASE</version>

		<relativePath/> <!-- lookup parent from repository -->

	</parent>

	<groupId>com.spring</groupId>

	<artifactId>nacos-gateway</artifactId>

	<version>0.0.1-SNAPSHOT</version>

	<name>nacos-gateway</name>

	<description>Demo project for Spring Boot</description>

	<properties>

		<java.version>1.8</java.version>

		<spring-cloud.version>Greenwich.SR2</spring-cloud.version>

	</properties>

	<dependencies>

		<dependency>

			<groupId>org.springframework.cloud</groupId>

			<artifactId>spring-cloud-starter-gateway</artifactId>

		</dependency>

		<dependency>

			<groupId>org.springframework.cloud</groupId>

			<artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>

			<version>0.9.0.RELEASE</version>

		</dependency>

		<dependency>

			<groupId>org.springframework.boot</groupId>

			<artifactId>spring-boot-starter-test</artifactId>

			<scope>test</scope>

		</dependency>

	</dependencies>

	<dependencyManagement>

		<dependencies>

			<dependency>

				<groupId>org.springframework.cloud</groupId>

				<artifactId>spring-cloud-dependencies</artifactId>

				<version>${spring-cloud.version}</version>

				<type>pom</type>

				<scope>import</scope>

			</dependency>

		</dependencies>

	</dependencyManagement>

	<build>

		<plugins>

			<plugin>

				<groupId>org.springframework.boot</groupId>

				<artifactId>spring-boot-maven-plugin</artifactId>

			</plugin>

		</plugins>

	</build>

</project>

3.2 配置文件application.xml

server:

  port: 8088

spring:

  application:

    name: spring-cloud-nacos-gateway

  cloud:

    nacos:

      discovery:

        server-addr: localhost:8848

    gateway:

      discovery:

        locator:

          enabled: true

      routes:

        - id: hello_route

          #格式为：lb://应用注册服务名

          uri: lb://spring-cloud-nacos-producer

          predicates:

            - Method=GET

3.3 启动类NacosGatewayApplication.java

package com.spring.nacosgateway;

import org.springframework.boot.SpringApplication;

import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication

public class NacosGatewayApplication {

	public static void main(String[] args) {

		SpringApplication.run(NacosGatewayApplication.class, args);

	}

}

3.4 测试

我们启动Gateway，打开浏览器访问链接：http://localhost:8088/spring-cloud-nacos-producer/hello?name=nacos，浏览器正常返回：hello nacos，producer is ready，证明我们通过服务网关来访问服务是正常的。

最后，我们打开看一下Nacos的服务列表：

这里我把消费者服务停止掉了，可以看到Nacos可以实时的显示出来。

Nacos就介绍到这里，有不清楚的可以给我留言~

Github-示例代码