Spring Cloud实战(四)-Spring Cloud Netflix Feign

概要

什么是Spring Cloud Netflix Feign?

怎么用Feign?

什么是Spring Cloud Netflix Feign?

Feign:Declarative REST clients.

Feign:是一个声明式的REST客户端.

在之前的例子中我们使用的有DiscoveryClient,LoadBalancerClient,如他们一样FeignClient也是调用Eureka Server中服务用的,不过它提供了声明式的REST风格的调用,使编程更加简单.它是在运行时Runtime实现接口的实现,所以pom可以指定运行时依赖.

怎么用Feign?

百说不如一run,构造一个例子来实现

Eureka Server 如之前一样,正常启动即可

Eureka-Client 修改bootstrap.xml,变得简单一点,只有noun服务

spring:
application:
name: noun
server:
port: 8030
eureka:
client:
service-url:
defaultZone: http://127.0.0.1:8010/eureka/

Sentence-Client添加NounClient接口

@FeignClient("noun")
public interface NounClient {

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

Sentence-Client添加pom.xml

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

Sentence-Client在Application添加@EnableFeignClients

Sentence-Client在SentenceController中使用NounClient

@RestController
public class SentenceController {

@Autowired
private NounClient nounClient;
@RequestMapping("/sentence")
public @ResponseBody
String getSentence() {
return
"<h3>造句:</h3><br/>" +
buildSentence() + "<br/><br/>" +
buildSentence() + "<br/><br/>" +
buildSentence() + "<br/><br/>" +
buildSentence() + "<br/><br/>" +
buildSentence() + "<br/><br/>"
;
}
public String buildSentence() {
String sentence = "There was a problem assembling the sentence!";
try{
sentence =  nounClient.getWord();
} catch ( Exception e ) {
System.out.println(e);
}
return sentence;
}

}

现在去http://127.0.0.1:8080/sentence检查下是否调用服务成功吧

特别感谢 kennyk65

Spring Cloud 中文用户组 31777218
Spring-Cloud-Config 官方文档-中文译本 (本人有参与,哈哈)
Spring Cloud Netflix 官网文档-中文译本

本文实例github地址 mmb-feign

原文地址：https://segmentfault.com/a/1190000006188802