SpringCloud之Feign示例详解
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2023-12-16 23:56:10
feign简介
feign 是一个声明web服务客户端,这便得编写web服务客户端更容易,使用feign 创建一个接口并对它进行注解,它具有可插拔的注解支持包括feign...
feign简介
feign 是一个声明web服务客户端,这便得编写web服务客户端更容易,使用feign 创建一个接口并对它进行注解,它具有可插拔的注解支持包括feign注解与jax-rs注解,feign还支持可插拔的编码器与解码器,spring cloud 增加了对 spring mvc的注解,spring web 默认使用了httpmessageconverters, spring cloud 集成 ribbon 和 eureka 提供的负载均衡的http客户端 feign.
声明式rest客户端:feign
先要启动eureka_register_service工程(注册中心)和biz-service-0工程(服务生产者)
创建一个maven工程eureka_feign_client
pom.xml
<parent> <groupid>org.springframework.boot</groupid> <artifactid>spring-boot-starter-parent</artifactid> <version>1.4.3.release</version> <relativepath/> <!-- lookup parent from repository --> </parent> <properties> <project.build.sourceencoding>utf-8</project.build.sourceencoding> <java.version>1.8</java.version> </properties> <dependencies> <dependency> <groupid>org.springframework.cloud</groupid> <artifactid>spring-cloud-starter-feign</artifactid> </dependency> <dependency> <groupid>org.springframework.cloud</groupid> <artifactid>spring-cloud-starter-eureka</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-test</artifactid> <scope>test</scope> </dependency> </dependencies> <dependencymanagement> <dependencies> <dependency> <groupid>org.springframework.cloud</groupid> <artifactid>spring-cloud-dependencies</artifactid> <version>brixton.sr5</version> <type>pom</type> <scope>import</scope> </dependency> </dependencies> </dependencymanagement>
在应用主类中通过@enablefeignclients注解开启feign功能
启动文件feignapplication.java
@springbootapplication @enablediscoveryclient @enablefeignclients public class feignapplication { public static void main(string[] args) { springapplication.run(feignapplication.class, args); } }
定义服务接口类userclient.java
使用@feignclient("biz-service-0")注解来绑定该接口对应biz-service-0服务
@feignclient("biz-service-0") public interface userclient { @requestmapping(method = requestmethod.get, value = "/getuser") public user getuserinfo(); @requestmapping(method = requestmethod.get, value = "/getuser") public string getuserinfostr(); @requestmapping(method = requestmethod.get, value = "/info") public string info(); }
在web层中调用上面定义的usercontroller,具体如下
@restcontroller public class usercontroller { @autowired userclient userclient; @requestmapping(value = "/getuserinfo", method = requestmethod.get) public user getuserinfo() { return userclient.getuserinfo(); } @requestmapping(value = "/getuserinfostr", method = requestmethod.get) public string getuserinfostr() { return userclient.getuserinfostr(); } @requestmapping(value = "/info", method = requestmethod.get) public string info() { return userclient.info(); } }
application.properties配置变量
spring.application.name=feign-consumer server.port=8004 eureka.client.serviceurl.defaultzone=http://localhost:8000/eureka/
访问 http://127.0.0.1:8004/getuserinfo
总结:
其实通过feign封装了http调用服务方法,使得客户端像调用本地方法那样直接调用方法,类似dubbo中暴露远程服务的方式,区别在于dubbo是基于私有二进制协议,而feign本质上还是个http客户端
以上就是本文的全部内容,希望对大家的学习有所帮助,也希望大家多多支持。