【springcloud】通过Feign调用传递Header中的参数

一时失言乱红尘 2022-09-08 00:13 174阅读 0赞

如何通过feign调用传递header参数

**问题描述**

我们在SpringCloud中使用Feign请求另一个服务的Api接口时，有将Header中参数传递下去的需求，如果不做特殊处理，就会将Header中的参数丢失。

解决方案：

## **方案一** ##

通过@RequestHeader(name = "name")

例如：Feign定义如下

>     @FeignClient(name = "service-name")
>     public interface XXXFeignClient {
>         @RequestMapping(value = "/user/getUserTicket", method = RequestMethod.GET)
>         String getUserTicket(@RequestParam("id") String id);
>     }

假设在服务service-name中的/user/getUserTicket接口需要从Header中取Referer数据，那么我们可以将上面代码进行改造：

然后在调用的时候将referer参数传递进去即可，如

>     public String getTicketById(@RequestParam("id") String id, HttpServletRequest request) {
>             String referer = request.getHeader("Referer");
>             return xxxFeignClient.getUserTicket(id, referer);
>         }

## 方案二 ##

通过实现 RequestInterceptor 接口

首先，自定义实现RequestInterceptor接口的apply方法，如下

>     import org.springframework.stereotype.Configuration;
>     import org.springframework.web.context.request.RequestContextHolder;
>     import org.springframework.web.context.request.ServletRequestAttributes;
>     import javax.servlet.http.HttpServletRequest;
>     import java.util.Enumeration;
>     @Configuration
>     public class FeignConfiguration implements RequestInterceptor {
>         @Override
>         public void apply(RequestTemplate requestTemplate) {
>             ServletRequestAttributes attributes = (ServletRequestAttributes) RequestContextHolder
>                     .getRequestAttributes();
>             HttpServletRequest request = attributes.getRequest();
>             Enumeration<String> headerNames = request.getHeaderNames();
>             if (headerNames != null) {
>                 while (headerNames.hasMoreElements()) {
>                     String name = headerNames.nextElement();
>                     String values = request.getHeader(name);
>                     requestTemplate.header(name, values);
>                 }
>             }
>         }
>     }

然后将自定义的配置类配置到Feign中，就可以实现该Feign中接口Header参数的传递

>     @FeignClient(value = "service-name" ,configuration = FeignConfiguration.class)
>         public interface XXXFeignClient {
>         }