1、服务提供者

• service-01工程修改（提供接口，自己写一个controller测试一下）

package com.wyh.controller;

import com.wyh.service.TestService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
@RequestMapping("/test")
public class TestController {

    @Autowired
    private TestService testService;

    @GetMapping("/messgae")
    public String messgae() {
        return testService.testMessage();
    }
}

package com.wyh.service;


public interface TestService {

    /**
     * 测试 Fegin 调用
     *
     * @return message
     */
    String testMessage();

}

package com.wyh.service.impl;

import com.wyh.service.TestService;
import org.springframework.stereotype.Service;

@Service
public class TestServiceImpl implements TestService {

    @Override
    public String testMessage() {
        return "------- hello 8001 ---------";
    }
}

• 把修改好的service-01工程copy一份，service-02，只需要修改端口即可

2、服务调用者

使用Feign实现远程服务调用，Ribbon实现负载均衡

• pom.xml

<?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">
    <parent>
        <artifactId>myspring-cloud</artifactId>
        <groupId>org.example</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>service-fegin-client</artifactId>
    <dependencies>

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

        <!--  web组件      -->
        <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>

        <!--mybatis-plush-->
        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-boot-starter</artifactId>
        </dependency>

        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-generator</artifactId>
        </dependency>

        <dependency>
            <groupId>org.apache.velocity</groupId>
            <artifactId>velocity-engine-core</artifactId>
        </dependency>

        <dependency>
            <groupId>org.freemarker</groupId>
            <artifactId>freemarker</artifactId>
        </dependency>

        <dependency>
            <groupId>cn.hutool</groupId>
            <artifactId>hutool-all</artifactId>
        </dependency>

        <!--redis-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-redis</artifactId>
        </dependency>

        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-commons</artifactId>
        </dependency>

        <!--  open feign      -->
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-openfeign</artifactId>
        </dependency>

    </dependencies>

</project>

• main 服务启动类

package com.wyh;

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 ServiceFeginClient {

    public static void main(String[] args) {
        SpringApplication.run(ServiceFeginClient.class, args);
    }

}

• service.feign

package com.wyh.service.feign;

import org.springframework.cloud.openfeign.FeignClient;
import org.springframework.stereotype.Component;
import org.springframework.web.bind.annotation.GetMapping;

@Component

//服务名称
@FeignClient(value = "service-test")
public interface TestService {

    /**
     * 服务提供的 api 接口
     *
     * @return 结果集
     */
    @GetMapping(value = "/test/messgae")
    String sayHellow();

}

• controller

package com.wyh.controller;

import com.wyh.service.feign.TestService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
@RequestMapping("/test")
public class feignTestController {

    @Autowired
    private TestService testService;

    @GetMapping("/fegin-test")
    public String messgae() {
        return testService.sayHellow();
    }
}

3、测试

• 同时启动四个服务（nacos-config）

  
  
  nacos.png

• 自动实现负载均衡

  
  
  service-01.png
  
  
  service-02.png