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
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~