测试member和coupon的远程调用

测试member和coupon的远程调用

想要获取当前会员领取到的所有优惠券。先去注册中心找优惠券服务，
注册中心调一台优惠券服务器给会员，会员服务器发送请求给这台优
惠券服务器，然后对方响应。

Feign与注册中心
spring cloud feign

声明式远程调用

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 会员服务想要远程调用优惠券服务，只需要给会员服务里引入
openfeign依赖，他就有了远程调用其他服务的能力。

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

2 在coupon中修改如下的内容
@RequestMapping("coupon/coupon")
public class CouponController {
    @Autowired
    private CouponService couponService;

    @RequestMapping("/member/list")
    public R membercoupons(){    //全系统的所有返回都返回R
        // 应该去数据库查用户对于的优惠券，但这个我们简化了，不去数据库查了，构造了一个优惠券给他返回
        CouponEntity couponEntity = new CouponEntity();
        couponEntity.setCouponName("满100减10");//优惠券的名字
        return R.ok().put("coupons",Arrays.asList(couponEntity));
    }

3 这样我们准备好了优惠券的调用内容
在member的配置类上加注解@EnableFeignClients(basePackages="com.yxj.gulimall.member.feign")，
告诉spring这里面是一个远程调用客户端，member要调用的接口

package com.yxj.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;

@SpringBootApplication
@MapperScan("com.yxj.gulimall.member.dao")
@EnableDiscoveryClient
@EnableFeignClients(basePackages="com.yxj.gulimall.member.feign")
public class GulimallMemberApplication {

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

}

4 那么要调用什么东西呢？就是我们刚才写的优惠券的功能，
复制函数部分，在member的com.yxj.gulimall.member.feign包下新建类：
package com.yxj.gulimall.member.feign;

import com.yxj.common.utils.R;
import org.springframework.cloud.openfeign.FeignClient;
import org.springframework.web.bind.annotation.RequestMapping;

@FeignClient("gulimall-coupon") //告诉spring cloud这个接口是一个远程客户端，要调用coupon服务，再去调用coupon服务/coupon/coupon/member/list对应的方法
public interface CouponFeignService {
    @RequestMapping("/coupon/coupon/member/list")
    public R membercoupons();//得到一个R对象
}

5 然后我们在member的控制层写一个测试请求
@RestController
@RequestMapping("member/member")
public class MemberController {
    @Autowired
    private MemberService memberService;

    @Autowired
    CouponFeignService couponFeignService;

    @RequestMapping("/coupons")
    public R test(){
        MemberEntity memberEntity = new MemberEntity();
        memberEntity.setNickname("张三");
        R membercoupons = couponFeignService.membercoupons(); //假设张三去数据库查了后返回了张三的优惠券信息

        // 打印会员和优惠券信息
        return R.ok().put("member",memberEntity).put("coupons",membercoupons.get("coupons"));
    }

	6 重新启动服务
	http://localhost:8000/member/member/coupons
	{"msg":"success","code":0,"coupons":[{"id":null,"couponType":null,"couponImg":null,"couponName":"满100减10","num":null,"amount":null,"perLimit":null,"minPoint":null,"startTime":null,"endTime":null,"useType":null,"note":null,"publishCount":null,"useCount":null,"receiveCount":null,"enableStartTime":null,"enableEndTime":null,"code":null,"memberLevel":null,"publish":null}],"member":{"id":null,"levelId":null,"username":null,"password":null,"nickname":"张三","mobile":null,"email":null,"header":null,"gender":null,"birth":null,"city":null,"job":null,"sign":null,"sourceType":null,"integration":null,"growth":null,"status":null,"createTime":null}}

	7 上面内容很重要，我们停留5分钟体会一下。
		coupon里的R.ok()是什么 # coupon里的控制层就是new了个couponEntity然后放到hashmap（R）里而已。
		public class R extends HashMap<String, Object> {
			public static R ok() {
				return new R();
			}

			public R put(String key, Object value) {
				super.put(key, value);
				return this;
			}

		}