创建服务消费者(Feign)

概述

Feign 是一个声明式的伪 Http 客户端，它使得写 Http 客户端变得更简单。使用 Feign，只需要创建一个接口并注解。它具有可插拔的注解特性，可使用 Feign 注解和 JAX-RS 注解。Feign 支持可插拔的编码器和解码器。Feign 默认集成了 Ribbon，并和 Eureka 结合，默认实现了负载均衡的效果

Feign 采用的是基于接口的注解

Feign 整合了 ribbon和hystrix

创建服务消费者

       <dependency>            <groupId>org.springframework.cloud</groupId>            <artifactId>spring-cloud-starter-eureka</artifactId>        </dependency>​        <!--spring cloud starter feign-->        <dependency>            <groupId>org.springframework.cloud</groupId>            <artifactId>spring-cloud-starter-feign</artifactId>        </dependency>​        <dependency>            <groupId>org.springframework.boot</groupId>            <artifactId>spring-boot-starter-web</artifactId>        </dependency>​

主要增加对Feign的依赖

Application

通过@EnableFeignClients注解开启Feign功能

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;​@EnableFeignClients@EnableDiscoveryClient@SpringBootApplicationpublic class FeignApplication {​    public static void main(String[] args) {        SpringApplication.run(FeignApplication.class, args);   }}​

application.yml

server: port: 9002​eureka: client:   serviceUrl:     defaultZone: http://localhost:1111/eureka/ instance:   lease-renewal-interval-in-seconds: 10 #服务续约   lease-expiration-duration-in-seconds: 15 #服务剔除>服务续约时间   hostname: localhost   instance-id: ${eureka.instance.hostname}:${spring.application.name}:${server.port}spring: application:   name: eureka-client-feignfeign: client:   config:     eureka-provider:     #配置feign日志级别       logger-level: full  #开启feign对hystrix的支持,默认为false hystrix:   enabled: truelogging: level: #必须设置feign的服务包日志级别为debug   com.ley.springcloud.feign.service: debug

 

创建Feign接口

通过@FeignClient("服务名")注解来指定调用哪个服务

import org.springframework.cloud.netflix.feign.FeignClient;import org.springframework.web.bind.annotation.GetMapping;​@FeignClient(name = "eureka-provider")public interface HelloService {​    @GetMapping("/hello")    String hello();}​

 

创建测试用的Controller

import com.ley.springcloud.feign.service.HelloService;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.web.bind.annotation.GetMapping;import org.springframework.web.bind.annotation.RequestMapping;import org.springframework.web.bind.annotation.RestController;​@RestController@RequestMapping("/api")public class FeignController {​    @Autowired    private HelloService helloService;​    @GetMapping("/feign/hello")    public String hello() {        return helloService.hello();   }}

 

转载于:https://www.cnblogs.com/liuenyuan1996/p/10288722.html