SpringCloud成长笔记（三）feign、openfeign

最新推荐文章于 2025-07-04 14:41:44 发布

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#springboot2.1 #springcloud2.1 #eureka #feign

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一、环境搭建

基于上一张的工程，我们再复制一份，去掉git文件夹，修改pom.xml的工程名，重新导入到idea。
新建module->feign,引入feign的依赖
在这里插入图片描述
发现，feign的依赖不可用，这是我们发现spring-boot2.1.0.RELEASE,spring-cloud的版本是Greenwich.M1。openfeign依赖的版本不支持。所以要么降springcloud版本，要么就重新配置依赖。我们选择重新配置依赖。
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>

	<groupId>com.example</groupId>
	<artifactId>feign</artifactId>
	<version>0.0.1-SNAPSHOT</version>
	<packaging>jar</packaging>

	<name>feign</name>
	<description>Demo project for Spring Boot</description>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <java.version>1.8</java.version>
        <openfeign.version>2.0.0.M1</openfeign.version>
        <feign.version>9.5.1</feign.version>
        <spring-boot.version>2.1.0.RELEASE</spring-boot.version>
        <spring-cloud.version>Greenwich.M1</spring-cloud.version>
    </properties>

    <!--springboot版本2.1.0-->
	<parent>
		<groupId>org.springframework.boot</groupId>
		<artifactId>spring-boot-starter-parent</artifactId>
		<version>2.1.0.RELEASE</version>
		<relativePath/> <!-- lookup parent from repository -->
	</parent>


	<dependencies>
		<!--springcloud 版本-->
		<dependency>
			<groupId>org.springframework.cloud</groupId>
			<artifactId>spring-cloud-starter</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>

        <dependency>
            <groupId>io.github.openfeign</groupId>
            <artifactId>feign-core</artifactId>
            <version>${feign.version}</version>
        </dependency>
        <dependency>
            <groupId>io.github.openfeign</groupId>
            <artifactId>feign-slf4j</artifactId>
            <version>${feign.version}</version>
        </dependency>
        <dependency>
            <groupId>io.github.openfeign</groupId>
            <artifactId>feign-hystrix</artifactId>
            <version>${feign.version}</version>
        </dependency>
        <dependency>
            <groupId>io.github.openfeign</groupId>
            <artifactId>feign-java8</artifactId>
            <version>${feign.version}</version>
        </dependency>
        <dependency>
            <groupId>io.github.openfeign.form</groupId>
            <artifactId>feign-form-spring</artifactId>
            <version>3.2.2</version>
        </dependency>
		<!--feign-->
		<!--<dependency>
			<groupId>org.springframework.cloud</groupId>
			<artifactId>spring-cloud-starter-feign</artifactId>
        </dependency>-->

		<!--<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-autoconfigure</artifactId>
		</dependency>-->
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-eureka-server</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-ribbon</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-hystrix</artifactId>
        </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>

           <!-- <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-openfeign</artifactId>
                <version>${openfeign.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>

	<repositories>
		<repository>
			<id>spring-milestones</id>
			<name>Spring Milestones</name>
			<url>https://repo.spring.io/milestone</url>
			<snapshots>
				<enabled>false</enabled>
			</snapshots>
		</repository>
	</repositories>


</project>

启动两个客户端
编译好之后，进入target目录，
java -jar client*.jar --spring.profiles.active=dev
或者java -jar client-0.0.1-SNAPSHOT.jar --server.port=8093
java -jar client-0.0.1-SNAPSHOT.jar --server.port=8091

二、代码

服务器名称为server1，客户端名为eureka-client，feign客户端名为feign-client
feign重要的代码是接口配置

package com.mhm.feignInterface;

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

/**
 * Created by MHm on 2018/11/19.
 */
@FeignClient(value = "eureka-client")
public interface FeignService {
    @RequestMapping(value="/eureka",method = RequestMethod.GET)
    String index(@RequestParam(value = "name") String name);
}

其中，FeignClient就是我们eureka-client的名称，index为各个客户端实现的方法。
Feign的restful接口如下：

package com.mhm.controller;

import com.mhm.feignInterface.FeignService;
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.RequestParam;
import org.springframework.web.bind.annotation.RestController;

/**
 * Created by MHm on 2018/11/19.
 */
@RestController
public class FeignControler {
    @Autowired
    private FeignService feignService;

    @RequestMapping(value = "/eureka",method = RequestMethod.GET)
    public String index(@RequestParam String name){
        return feignService.index(name);
    }
}