微服务调用的时候请求不会传递参数.比如调用方服务请求头中有cookie存放sessionId,而被调用方服务没有请求头,从而没有cookie信息,也就不能根据cookie中存放的sessionId获取session信息,影响后续操作.

解决办法
通过实现RequestInterceptor接口,完成对所有的Feign请求,传递请求头和请求参数。本质是通过ThreadLocal线程共享变量实现.

import feign.RequestInterceptor;
import feign.RequestTemplate;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.context.request.RequestContextHolder;
import org.springframework.web.context.request.ServletRequestAttributes;

@Configuration
public class FeignConfig {

    /**
     * 解决feign远程调用丢失请求头的问题
     * @return
     */
    @Bean
    public RequestInterceptor requestInterceptor(){
        return new RequestInterceptor(){
            @Override
            public void apply(RequestTemplate requestTemplate) {
                //老请求 获取老请求的cookie信息
                ServletRequestAttributes requestAttributes = (ServletRequestAttributes) RequestContextHolder.getRequestAttributes();
                if (requestAttributes != null){
                    String cookie = requestAttributes.getRequest().getHeader("Cookie");
                    //同步到新请求中
                    requestTemplate.header("Cookie",cookie);
                }
            }
        };
    }
}