SpringCloudAlibaba系列之Nacos实战

目录

注意事项

参考资源

Nacos配置中心

初始化项目

进行Nacos相关配置

运行

Nacos注册中心

dubbo方式

对外暴露接口dubbo-api

服务提供者dubbo-provider

服务消费者dubbo-consumer

负载均衡客户端方法

服务提供者

服务消费者

---

注意事项

不管是使用Nacos配置中心，还是使用Nacos注册中心，大家一定要注意SpringCloudAlibaba和SpringBoot的版本对应关系，以免实际开发过程中出现各种莫名其妙的问题。下图供大家参考(非最新的对应关系)

参考资源

Nacos环境准备参考官网链接：Nacos 快速开始 | Nacos?

Nacos配置中心和注册中心底层原理实现分析可参考如下链接：

SpringCloudAlibaba系列之Nacos配置管理

SpringCloudAlibaba系列之Nacos服务注册与发现

示例代码源码参考地址：https://gitee.com/williamjava/spring_cloud_alibaba_practise?

Nacos配置中心

初始化项目

• 核心maven依赖

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

<dependencyManagement>
       <dependencies>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>Hoxton.SR4</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
            <dependency>
                <groupId>com.alibaba.cloud</groupId>
                <artifactId>spring-cloud-alibaba-dependencies</artifactId>
                <version>2.2.1.RELEASE</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>

• 增加项目中配置文件yml

spring:
  application:
    name: alibaba-nacos-config-client
  cloud:
    nacos:
      config:
        server-addr: localhost:8848
        file-extension: yaml

server:
  port: 8604

• ?创建测试Controller

package com.gui.alibaba.nacos.config.controller;

import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.cloud.context.config.annotation.RefreshScope;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;

/**
 * 注解：RefreshScope
 * 主要用来让这个类下的配置内容支持动态刷新，也就是当我们的应用启动之后，修改了Nacos中的配置内容之后，这里也会马上生效
 */
@Slf4j
@RestController
@RefreshScope
public class TestController {

    @Value("${practise.title:本地默认内容}")
    private String title;

    @GetMapping("/test")
    public String hello() {
        return title;
    }
}

进行Nacos相关配置

Nacos控制台增加配置文件，配置文件名称(Data ID)与spring.application.name保持一致，具体内容如下：

运行

启动项目，浏览器访问：http://localhost:8604/test

我们得到了配置中心中配置的内容，如果Nacos控制台直接修改配置的内容，刷新页面能实时获取到最新的数据，起关键作用的是@RefreshScope注解，可动态刷新Nacos配置。?

Nacos注册中心

dubbo方式

对外暴露接口dubbo-api

package com.sc.ali.dubbo.api;

public interface HelloService {
    String hello(String name);
}

服务提供者dubbo-provider

• 核心maven依赖

<!-- Dubbo Spring Cloud Starter -->
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-dubbo</artifactId>
        </dependency>

        <!-- Spring Cloud Nacos Service Discovery -->
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
        </dependency>

<!--API-->
        <dependency>
            <groupId>com.ali.sc.dubbo.api</groupId>
            <artifactId>dubbo-api</artifactId>
            <version>1.0-SNAPSHOT</version>
        </dependency>

<dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>Hoxton.SR4</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
            <dependency>
                <groupId>com.alibaba.cloud</groupId>
                <artifactId>spring-cloud-alibaba-dependencies</artifactId>
                <version>2.2.1.RELEASE</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>

• ?项目中配置文件yml

spring:
  application:
    name: dubbo-provider
  cloud:
    nacos:
      discovery:
        #nacos配置中心地址
        server-addr: localhost:8848
  main:
    allow-bean-definition-overriding: true


server:
  port: 8090
dubbo:
  scan:
    #dubbo扫描包路径
    base-packages: com.sc.ali.dubbo.provider.service
  protocol:
    name: dubbo
    port: -1
  registry:
    address: spring-cloud://localhost

• 服务实现类

package com.sc.ali.dubbo.provider.service;

import com.sc.ali.dubbo.api.HelloService;
import org.apache.dubbo.config.annotation.Service;

@Service
public class HelloServiceImpl implements HelloService {
    @Override
    public String hello(String s) {
        return "Hello, " + s + "，welcome....";
    }
}

• ?启动服务提供者

Nacos工作台服务列表中可看到服务提供者对应的服务。

服务消费者dubbo-consumer

• 核心maven依赖

<!-- Dubbo Spring Cloud Starter -->
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-dubbo</artifactId>
        </dependency>

        <!-- Spring Cloud Nacos Service Discovery -->
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
        </dependency>

<!--API-->
        <dependency>
            <groupId>com.ali.sc.dubbo.api</groupId>
            <artifactId>dubbo-api</artifactId>
            <version>1.0-SNAPSHOT</version>
        </dependency>

<dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>Hoxton.SR4</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
            <dependency>
                <groupId>com.alibaba.cloud</groupId>
                <artifactId>spring-cloud-alibaba-dependencies</artifactId>
                <version>2.2.1.RELEASE</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>

• 项目中配置文件yml

spring:
  application:
    name: dubbo-consumer
  cloud:
    nacos:
      discovery:
        #Nacos服务注册中心地址
        server-addr: localhost:8848
  main:
    allow-bean-definition-overriding: true


server:
  port: 8091
dubbo:
  protocol:
    name: dubbo
    port: -1
  registry:
    address: spring-cloud://localhost
  cloud:
    #指定需要订阅的服务
    subscribed-services: dubbo-provider

• 添加测试controller，完成服务调用

package com.sc.ali.dubbo.consumer.controller;

import com.sc.ali.dubbo.api.HelloService;
import org.apache.dubbo.config.annotation.Reference;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class HelloController{
    @Reference
    private HelloService helloService;

    @GetMapping("/hello")
    public String hello(String name) {
        return helloService.hello(name);
    }
}

• ?运行输出结果

负载均衡客户端方法

服务提供者

• 核心maven依赖

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

<dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>Hoxton.SR4</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
            <dependency>
                <groupId>com.alibaba.cloud</groupId>
                <artifactId>spring-cloud-alibaba-dependencies</artifactId>
                <version>2.2.1.RELEASE</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>

• 项目中配置文件yml

spring:
  application:
    name: alibaba-nacos-discovery-server
  cloud:
    nacos:
      #Nacos注册中心地址
      server-addr: localhost:8848

server:
  port: 8601

• ?对外暴露的服务方法

package com.gui.alibaba.nacos.discovery.controller;

import lombok.extern.slf4j.Slf4j;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;

@RestController
@Slf4j
public class TestController {
    @GetMapping("/hello")
    public String hello(@RequestParam String name) {
        log.info("invoked name = " + name);
        return "hello " + name;
    }
}

• 启动服务提供者

Nacos工作台服务列表可找到对应的服务

服务消费者

• 核心maven依赖

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

<dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>Hoxton.SR4</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
            <dependency>
                <groupId>com.alibaba.cloud</groupId>
                <artifactId>spring-cloud-alibaba-dependencies</artifactId>
                <version>2.2.1.RELEASE</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>

• 项目中配置文件yml

spring:
  application:
    name: alibaba-nacos-discovery-client
  cloud:
    nacos:
      discovery:
        server-addr: localhost:8848

server:
  port: 8602

• ?添加测试controller，完成服务调用

package com.gui.alibaba.nacos.client.controller;

import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
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
@Slf4j
public class TestController {
    @Autowired
    private LoadBalancerClient loadBalancerClient;

    @GetMapping("/test")
    public String test() {
        // 通过spring cloud common中的负载均衡接口选取服务提供节点实现接口调用
        ServiceInstance serviceInstance = loadBalancerClient.choose("alibaba-nacos-discovery-server");
        //构造请求URL
        String url = serviceInstance.getUri() + "/hello?name=" + "william";

        //创建RestTemplate对象，通过Restful接口调用具体服务
        RestTemplate restTemplate = new RestTemplate();
        String result = restTemplate.getForObject(url, String.class);

        return "Invoke : " + url + ", return : " + result;
    }
}

• 运行输出结果