SpringCloud-OpenFeign远程调用

Feign是一个声明式的HTTP客户端，他的目的就是让远程调用更加简单。给远程服务发的是HTTP请求。

1.引入Open-Feign

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

2.编写一个被调用的接口

@RestController
@RequestMapping("coupon/coupon")
public class CouponController {
    @RequestMapping("/member/list")
    public R membercoupons(){
        CouponEntity couponEntity = new CouponEntity();
        couponEntity.setCouponName("100减1");
        return R.ok().put("coupons",Arrays.asList(couponEntity));
    }
}

3.远程调用的微服务模块新建一个接口

/**
 * 这是一个声明式的远程调用,编写的路径以及方法名要一致
 */
@FeignClient("gulimall-coupon")
public interface CouponFeignService {
    @RequestMapping("/coupon/coupon/member/list")
    public R membercoupons();
}

4.开启远程调用功能

@RestController
@RequestMapping("member/member")
public class MemberController {
    @Autowired
    CouponFeignService couponFeignService;

    @RequestMapping("/coupons")
    public R test(){
        MemberEntity memberEntity = new MemberEntity();
        memberEntity.setNickname("柚子");
        R membercoupons = couponFeignService.membercoupons();
        
        return R.ok().put("member",memberEntity)
                    .put("coupons",membercoupons.get("coupons"));
    }
}

5.启动类添加注解@EnableFeignClients

package com.atguigu.gulimall.member;

import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
import org.springframework.cloud.openfeign.EnableFeignClients;

//开启远程调用的注解 @EnableFeignClients
@EnableFeignClients(basePackages = "com.atguigu.gulimall.member.fegin")
@MapperScan(basePackages = "com.atguigu.gulimall.member.dao")
@EnableDiscoveryClient
@SpringBootApplication
public class GulimallMemberApplication {

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

}