GuLi商城-SpringCloud-OpenFeign测试远程调用

约定不等于承诺〃 2024-03-26 10:38 50阅读 0赞

1. Feign 简介

Feign 是一个声明式的 HTTP 客户端，它的目的就是让远程调用更加简单。Feign 提供了HTTP请

求的模板，通过编写简单的接口和插入注解，就可以定义好 HTTP 请求的参数、格式、地址等信

息。Feign 整合了 Ribbon（负载均衡）和 Hystrix(服务熔断)，可以让我们不再需要显式地使用这

两个组件。

SpringCloudFeign 在 NetflixFeign 的基础上扩展了对 SpringMVC 注解的支持，在其实现下，我们

只需创建一个接口并用注解的方式来配置它，即可完成对服务提供方的接口绑定。简化了

SpringCloudRibbon 自行封装服务调用客户端的开发量。  
  
原文链接：https://blog.csdn.net/m0\_51111980/article/details/126672271

2.Feign使用

之前创建微服务模块的时候就已经引入了依赖jar

![0b61e0df8c524e089f73abf02105f1f3.png][]

编写接口，告诉springcloud这个接口需要调用远程服务

这里以会员服务member想要调用优惠卷服务coupon的/coupon/coupon/member/list接口为例，需

要在member服务中心编写一个接口。

![7bc3ddde7bf04111b638b2d8906f2f73.png][]

首先在member模块创建远程调用接口的存放包名，然后在包内创建接口CouponFeignService，

在其中编写代码

@FeignClient("gulimall-coupon") gulimall-coupon是在nacos注册的服务名

![c55b4b73ebdc4b0882734655ea56f62a.png][]

在启动类上加上`@EnableFeignClients`开启远程调用

![f29275d1e6864b0daa09f38c5314cfed.png][]

在会员服务member的controller中写一个测试方法，调用远程接口

测试远程调用功能：

![50203388edcd415e9709be8e8b164cbf.png][]

准备启动两个微服务，结果会员微服务报错

No Feign Client for loadBalancing defined. Did you forget to include spring-cloud-starter-

loadbalancer?

![a3b2c9e1233d4072b93fb4348d0067ef.png][]

[No Feign Client for loadBalancing defined. Did you forget to include spring-cloud-starter-loadbalanc\_北海道恋人的博客-CSDN博客][No Feign Client for loadBalancing defined. Did you forget to include spring-cloud-starter-loadbalanc_-CSDN]

[nested exception is java.lang.IllegalStateException: No Feign Client for loadBalancing defined.\_\#晚来天欲雪的博客-CSDN博客][nested exception is java.lang.IllegalStateException_ No Feign Client for loadBalancing defined._-CSDN]

![89b50559890e40f983f85af31384942f.png][]

测试：

![7d6f7b37917641f28168879047f4dd03.png][]

检查发现是字母写错了，失误

![ca9a3fc8031a4739b5625c77510f1f64.png][]

测试OK

![c2380b251153411bbc294248f9cb06be.png][]

[0b61e0df8c524e089f73abf02105f1f3.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/26/e7616e2e4723460b9cba7102b5fa9b32.png
[7bc3ddde7bf04111b638b2d8906f2f73.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/26/d93b7b8c41a2478d9775ffbbd2f17fae.png
[c55b4b73ebdc4b0882734655ea56f62a.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/26/88dc8611fe5e4dddbfc58c8607c0e8ae.png
[f29275d1e6864b0daa09f38c5314cfed.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/26/d12ec94ec8324484a2c2516e6866ab8f.png
[50203388edcd415e9709be8e8b164cbf.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/26/b261fad97e13430d9a2b5d8d400d956a.png
[a3b2c9e1233d4072b93fb4348d0067ef.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/26/fc98a333ae95415b808e23ddaae6df7f.png
[No Feign Client for loadBalancing defined. Did you forget to include spring-cloud-starter-loadbalanc_-CSDN]: https://blog.csdn.net/weixin_43556636/article/details/110653989
[nested exception is java.lang.IllegalStateException_ No Feign Client for loadBalancing defined._-CSDN]: https://blog.csdn.net/YIZHILIUSHA2020/article/details/125016120
[89b50559890e40f983f85af31384942f.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/26/f333fc430b184cd7b1c57001044cb4a9.png
[7d6f7b37917641f28168879047f4dd03.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/26/a7c2e288ff29480291edab88a04877fa.png
[ca9a3fc8031a4739b5625c77510f1f64.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/26/86cea4e01e0e4923919ff88617baef39.png
[c2380b251153411bbc294248f9cb06be.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/26/2b174b88d0834b67a351ee72be749c0d.png