spring cloud alibaba - Nacos 作为注册中心基础使用-服务提供者和消费者

1.概况

　　服务提供者9001和9002，他们是同一个服务，服务消费者83

2.创建服务提供者

　　9001和9002除了端口是一样的，这里只演示一个

2.1项目结构

2.2依赖

nacos依赖

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

完整的

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

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-actuator</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
            <scope>runtime</scope>
            <optional>true</optional>
        </dependency>

        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>

        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>fastjson</artifactId>
            <version>1.2.62</version>
        </dependency>
    </dependencies>

2.3配置文件

server:
  port: 9001

spring:
  application:
    name: nacos-payment-provider  #将会作为注册到注册中心的服务名称
  cloud:
    nacos:
      discovery:
        server-addr: localhost:8848 #配置Nacos地址

management:
  endpoints:
    web:
      exposure:
        include: '*'

2.4主启动类

　　注解使用的是@EnableDiscoveryClient

package com.atguigu.springcloud;

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

/**
 * @Classname PaymentMain9001
 * @Description TODO
 * @Date 2021/6/18 0018 下午 2:20
 * @Created by jcc
 */
@SpringBootApplication
@EnableDiscoveryClient
public class PaymentMain9001 {
    public static void main(String[] args) {
        SpringApplication.run(PaymentMain9001.class,args);
    }
}

2.5业务类

package com.atguigu.springcloud.controller;

import org.springframework.beans.factory.annotation.Value;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RestController;

/**
 * @Classname PaymentController
 * @Description TODO
 * @Date 2021/6/18 0018 下午 2:21
 * @Created by jcc
 */
@RestController
public class PaymentController {
    @Value("${server.port}")
    private String serverPort;

    @GetMapping(value = "/payment/nacos/{id}")
    public String getPayment(@PathVariable("id") Integer id)
    {
        return "nacos registry, serverPort: "+ serverPort+"\t id"+id;
    }
}

3.创建服务消费者

3.1项目结构

 3.2依赖

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

完整

<dependencies>

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

        <dependency>
            <groupId>com.atguigu.springcloud</groupId>
            <artifactId>cloud-api-commons</artifactId>
            <version>${project.version}</version>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-actuator</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
            <scope>runtime</scope>
            <optional>true</optional>
        </dependency>

        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>

        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>fastjson</artifactId>
            <version>1.2.62</version>
        </dependency>
    </dependencies>

3.3配置文件

server:
  port: 83

spring:
  application:
    name: nacos-payment-consumer  #将会作为注册到注册中心的服务名称
  cloud:
    nacos:
      discovery:
        server-addr: localhost:8848 #配置Nacos地址

service-url:
  nacos-user-service: http://nacos-payment-provider

3.4主启动类

package com.atguigu.springcloud.alibaba.controller;

import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.client.RestTemplate;

import javax.annotation.Resource;

/**
 * @Classname OrderNacosController
 * @Description TODO
 * @Date 2021/6/18 0018 下午 2:58
 * @Created by jcc
 */

@RestController
@Slf4j
public class OrderNacosController {

    @Resource
    private RestTemplate restTemplate;

    @Value("${service-url.nacos-user-service}")
    private String serverURL;

    @GetMapping(value = "/consumer/payment/nacos/{id}")
    public String paymentInfo(@PathVariable("id") Long id) {

        return restTemplate.getForObject(serverURL+"/payment/nacos/"+id,String.class);

    }
}

3.5配置类和业务类

nacos集成了Ribbon

package com.atguigu.springcloud.alibaba.config;

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

/**
 * @Classname ApplicationContextConfig
 * @Description TODO
 * @Date 2021/6/18 0018 下午 2:56
 * @Created by jcc
 */
@Configuration
public class ApplicationContextConfig {

    @Bean
    @LoadBalanced  //nacos集成了Ribbon，这里是开启ribbon负载均衡
    public RestTemplate getRestTemplate()
    {
        return new RestTemplate();
    }
}

package com.atguigu.springcloud.alibaba.controller;

import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.client.RestTemplate;

import javax.annotation.Resource;

/**
 * @Classname OrderNacosController
 * @Description TODO
 * @Date 2021/6/18 0018 下午 2:58
 * @Created by jcc
 */

@RestController
@Slf4j
public class OrderNacosController {

    @Resource
    private RestTemplate restTemplate;

    @Value("${service-url.nacos-user-service}")
    private String serverURL;

    @GetMapping(value = "/consumer/payment/nacos/{id}")
    public String paymentInfo(@PathVariable("id") Long id) {

        return restTemplate.getForObject(serverURL+"/payment/nacos/"+id,String.class);

    }
}

4.启动三个服务

　　启动后，查看nacos管理页面，可以看到三个服务

　　

　　此时，访问服务消费者83，连续访问

　　http://localhost:83/consumer/payment/nacos/13

　　

　　连续访问，发现 9001和9002轮询提供服务，因为Ribbon默认的策略是轮询

　　关于ribbon的介绍：https://www.cnblogs.com/jthr/p/14694632.html