SpringCloud（7）--feign

最新推荐文章于 2024-09-28 12:46:25 发布

原创最新推荐文章于 2024-09-28 12:46:25 发布 · 240 阅读

0 ·

CC 4.0 BY-SA版权

文章标签：

#springcloud #feign

Spring Cloud 专栏收录该内容

8 篇文章

订阅专栏

本文介绍如何在Spring Cloud项目中使用Feign作为微服务消费端，通过定义接口实现服务调用，实现客户端负载均衡。文章详细展示了从创建项目、配置依赖到实现服务调用的全过程。

摘要生成于 C知道，由 DeepSeek-R1 满血版支持，前往体验 >

新建feign-consumer项目

添加依赖

<?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>eureka-server-1</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>jar</packaging>

<name>eureka-server-1</name>
<description>Demo project for Spring Boot</description>

<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>1.4.0.RELEASE</version>
<relativePath/> 
</parent>

<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
<java.version>1.8</java.version>
</properties>
<dependencyManagement>
<dependencies>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-dependencies</artifactId>
<version>Camden.SR7</version>
<type>pom</type>
<scope>import</scope>
</dependency>
</dependencies>
</dependencyManagement>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter</artifactId>
</dependency>

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


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

<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>

在启动类中添加@EnableFeignClients

package com.example.demo;

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

@SpringBootApplication
//启动Spring Cloud Feign功能
@EnableFeignClients
@EnableDiscoveryClient
public class FeignConsumerApplication {

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

添加HelloService接口

package com.example.demo;

import org.springframework.cloud.netflix.feign.FeignClient;
import org.springframework.web.bind.annotation.RequestMapping;
//@FeignClient注解指定服务名来绑定服务，用Spring MVC的注解来帮顶具体该服务提供的REST接口
@FeignClient("hello-service")
public interface HelloService {

@RequestMapping("/hello")
String hello();
}

添加ConsumerControler

package com.example.demo;

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 ConsumerController {

@Autowired
HelloService helloService;

@RequestMapping(value = "/feign-consumer", method = RequestMethod.GET)
public String helloConsumer() {
return helloService.hello();
}
}

启动eureka-server、eureka-server-1（8001、8002端口）、feign-consumer服务。

访问 http://localhost:9001/feign-consumer，我们可以看到Feign实现的消费者，依然是利用Ribbon维护了针对hello-service的服务列表信息，并且通过轮询实现了客户端负载均衡，与ribbon不同的是，Feign只需要定义服务绑定接口，以生命的方式，事项服务调用。