Idea下SpringCloud2实验（三、Eureka+Fegin服务消费）

一、创建SpringBoot的项目springcloud-eureka-customer，操作同上一篇

二、配置文件
1、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">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.1.4.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.jane</groupId>
    <artifactId>springcloud-eureka-customer</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>springcloud-eureka-customer</name>
    <description>Demo project for Spring Boot</description>

    <properties>
        <java.version>1.8</java.version>
        <spring-cloud.version>Greenwich.SR1</spring-cloud.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <!--open feign-->
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-openfeign</artifactId>
            <version>2.0.2.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-openfeign-core</artifactId>
            <version>2.0.2.RELEASE</version>
        </dependency>
        <!--feign-->
    </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>

2、启动文件

package com.jane.springcloudeurekacustomer;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
import org.springframework.cloud.openfeign.EnableFeignClients;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.ComponentScans;

@SpringBootApplication
@EnableDiscoveryClient
@EnableFeignClients(basePackages = "com.jane")
@ComponentScan("com.jane")
public class SpringcloudEurekaCustomerApplication {

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

}

3、application.properties

server.port=6020
spring.application.name=springcloud-eureka-customer
eureka.client.service-url.defaultZone=http://127.0.0.1:6001/eureka/
eureka.client.fetchRegistry=true

4、Fegin客户端TestFeginServiceClient

package com.jane.service;

import org.springframework.cloud.openfeign.FeignClient;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;

@FeignClient("springcloud-eureka-client-order")
public interface TestFeginServiceClient {

    @RequestMapping(value = "/test", method = RequestMethod.GET)
    public String test();
}

5、调用文件TestController

package com.jane.controller;

import com.jane.service.TestFeginServiceClient;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class TestController {

    @Autowired
    TestFeginServiceClient testService;

    /**
     * 普通Restful
     * @return
     */
    @RequestMapping(value = "/local", method = RequestMethod.GET)
    public String local() {
        return "本地local调用";

    }

    /**
     * 利用Fegin客户端实现RPC调用order服务
     * @return
     */
    @RequestMapping(value = "/order/test", method = RequestMethod.GET)
    public String test(){
        return testService.test();
    }

}

三、启动文件
1、服务中心

2、服务消费
2.1本地调用

2.2RPC调用

四、FeignClient本身集成了本地负载均衡Netflix的Ribbon，所以可以轻松实现负载均衡。
1、修改client-order端口号6011，多启动一个服务

2、消费服务多次调用结果如下：