概述

有的时候业务场景是不走正常路线的,业务场景千奇百怪的需求都有, 有的时候权限校验需要在网关那里统一鉴权,有的时候就需要下放到某个微服务去处理(不在网关那里统一鉴权)
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通常我们调用的接口都是有权限控制的，很多时候可能认证的值是通过参数去传递的，还有就是通过请求头去传递认证信息，比如 Basic 认证方式。 接口鉴权
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Feign 中我们可以直接配置 Basic 认证

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@Configuration  // 全局配置public class FeignConfig {@Beanpublic BasicAuthRequestInterceptor basicAuthRequestInterceptor() {retu new BasicAuthRequestInterceptor("fox", "123456");}}

**扩展点： feign.RequestInterceptor **
每次 feign 发起http调用之前，会去执行拦截器中的逻辑。

public interface RequestInterceptor {/*** Called for every request. Add data using methods on the supplied {@link RequestTemplate}.*/  void apply(RequestTemplate template);}

使用场景

1. 统一添加 header 信息；
2. 对 body 中的信息做修改或替换；

自定义拦截器实现认证逻辑

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FeignConfig

package feigndemo.config;import feigndemo.interceptor.FeignAuthRequestInterceptor;import feign.Logger;import feign.Request;import feign.codec.Decoder;import feign.codec.Encoder;import feign.jackson.JacksonDecoder;import feign.jackson.JacksonEncoder;import org.springframework.context.annotation.Bean;import org.springframework.context.annotation.Configuration; @Configuration  // 全局配置public class FeignConfig { /**  * 日志级别  * 通过源码可以看到日志等级有 4 种，分别是：  * NONE：不输出日志。  * BASIC：只输出请求方法的 URL 和响应的状态码以及接口执行的时间。  * HEADERS：将 BASIC 信息和请求头信息输出。  * FULL：输出完整的请求信息。  */ @Bean public Logger.Level feignLoggerLevel() { retu Logger.Level.FULL; }/** * 自定义拦截器 * @retu */@Beanpublic FeignAuthRequestInterceptor feignAuthRequestInterceptor(){retu new FeignAuthRequestInterceptor();}@Beanpublic Request.Options options() {retu new Request.Options(5000, 5000);}@Beanpublic Decoder decoder() {retu new JacksonDecoder();}@Beanpublic Encoder encoder() {retu new JacksonEncoder();}}

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FeignAuthRequestInterceptor

package feigndemo.interceptor;import feign.RequestInterceptor;import feign.RequestTemplate;import java.util.UUID;public class FeignAuthRequestInterceptor implements RequestInterceptor {@Overridepublic void apply(RequestTemplate template) {// 业务逻辑  模拟认证逻辑// 请求头携带tokenString access_token = "IAmToken"+UUID.randomUUID().toString();template.header("Authorization",access_token);}}

这样在feign远程调用的时候自动将Authorization携带到header里面了,然后服务的被调用方就可以从header里面获取这个信息了
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feign输出:

2022-01-13 12:18:04.322 DEBUG 79432 --- [nio-8055-exec-1] feigndemo.feign.OrderFeignService: [OrderFeignService#findOrderByUserId] ---> GET http://mall-order/order/findOrderByUserId/1 HTTP/1.12022-01-13 12:18:04.323 DEBUG 79432 --- [nio-8055-exec-1] feigndemo.feign.OrderFeignService: [OrderFeignService#findOrderByUserId] Authorization: IAmToken53ce45ea-dc4f-4908-9492-e4f6ac43c1c22022-01-13 12:18:04.323 DEBUG 79432 --- [nio-8055-exec-1] feigndemo.feign.OrderFeignService: [OrderFeignService#findOrderByUserId] ---> END HTTP (0-byte body)2022-01-13 12:18:04.640 DEBUG 79432 --- [nio-8055-exec-1] feigndemo.feign.OrderFeignService: [OrderFeignService#findOrderByUserId] <--- HTTP/1.1 200 (314ms)2022-01-13 12:18:04.640 DEBUG 79432 --- [nio-8055-exec-1] feigndemo.feign.OrderFeignService: [OrderFeignService#findOrderByUserId] connection: keep-alive2022-01-13 12:18:04.640 DEBUG 79432 --- [nio-8055-exec-1] feigndemo.feign.OrderFeignService: [OrderFeignService#findOrderByUserId] content-type: application/json2022-01-13 12:18:04.641 DEBUG 79432 --- [nio-8055-exec-1] feigndemo.feign.OrderFeignService: [OrderFeignService#findOrderByUserId] date: Thu, 13 Jan 2022 04:18:04 GMT2022-01-13 12:18:04.641 DEBUG 79432 --- [nio-8055-exec-1] feigndemo.feign.OrderFeignService: [OrderFeignService#findOrderByUserId] keep-alive: timeout=602022-01-13 12:18:04.641 DEBUG 79432 --- [nio-8055-exec-1] feigndemo.feign.OrderFeignService: [OrderFeignService#findOrderByUserId] transfer-encoding: chunked2022-01-13 12:18:04.641 DEBUG 79432 --- [nio-8055-exec-1] feigndemo.feign.OrderFeignService: [OrderFeignService#findOrderByUserId] 2022-01-13 12:18:04.641 DEBUG 79432 --- [nio-8055-exec-1] feigndemo.feign.OrderFeignService: [OrderFeignService#findOrderByUserId] {"msg":"success","code":0,"orders":[{"id":1,"userId":"1","commodityCode":"1","count":1,"amount":1}]}2022-01-13 12:18:04.641 DEBUG 79432 --- [nio-8055-exec-1] feigndemo.feign.OrderFeignService: [OrderFeignService#findOrderByUserId] <--- END HTTP (100-byte body)

服务提供者拦截器

当消费者调用这个服务提供者的时候,拦截器就可以在这里获取到header的token信息了.

@Slf4jpublic class AuthInterceptor implements HandlerInterceptor {@Overridepublic boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) {boolean flag = true;// 简单的认证逻辑  从请求头中获取AuthorizationString authorization = request.getHeader("Authorization");log.info("=========Authorization:"+authorization);if (StringUtils.isEmpty(authorization)){// 从请求参数中获取access_tokenString access_token = request.getParameter("access_token");if(StringUtils.isEmpty(access_token)){flag = false;}}retu flag;}}

代码地址

代码出自图灵学院, 我自己学完了做完作业又改造了一下.

https://gitee.com/zjj19941/ZJJ_Neaten5.10/tree/master/ZJJ_Feign/feign-interceptor
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先执行sql脚本,自己准备一个nacos服务,然后修改配置文件配置,
最后,启动 com.order.MallOrderApplication 和 feigndemo.MallUserFeignDemoApplication
然后postman发起get请求: localhost:8055/user/findOrderByUserId/1
就能看到效果了

补充：可以在yml中配置

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feign:  client:config:  mall-order:  #对应微服务requestInterceptors[0]:  #配置拦截器  feigndemo.interceptor.FeignAuthRequestInterceptor