FeignClient如何共享Header及踩坑过程记录

@Configuration
public class FeignInterceptor implements RequestInterceptor {
    @Override
    public void apply(RequestTemplate requestTemplate) {
        Map<String,String> headers = getHeaders(getHttpServletRequest());
        for(String headerName : headers.keySet()){
            requestTemplate.header(headerName, getHeaders(getHttpServletRequest()).get(headerName));
        }
    }
    private HttpServletRequest getHttpServletRequest() {
        try {
            return ((ServletRequestAttributes) RequestContextHolder.getRequestAttributes()).getRequest();
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }
    private Map<String, String> getHeaders(HttpServletRequest request) {
        Map<String, String> map = new LinkedHashMap<>();
        Enumeration<String> enumeration = request.getHeaderNames();
        while (enumeration.hasMoreElements()) {
            String key = enumeration.nextElement();
            if(needThisHeader(key)){
               String value = request.getHeader(key);
               map.put(key, value);
            }
        }
        return map;
    }
  private boolean needThisHeader(String headerName){
     //todo:这里写你的逻辑，哪些header需要传递，千万不能把所有的header传下去
      return true;
  }
}

@Configuration
public class FeignSupportConfig {
    /**
     * feign请求拦截器
     *
     * @return
     */
    @Bean
    public RequestInterceptor requestInterceptor(){
        return new FeignInterceptor();
    }
}

@FeignClient(name = "kafka-client", url = "http://kafka.xxx.com")
public interface KafkaClient {
    @GetMapping(value = "/api/clusterManager/listTopics"）
    @Headers( {"cache-control: no-cache", "username: wangyong@xxx.com"})
    TopicsResponse listTopics(@RequestParam("clusterName") String clusterName,
                              @RequestParam("clusterArea") String clusterArea);
}

{
    "timestamp": 1551768926170,
    "status": 500,
    "error": "Internal Server Error",
    "exception": "com.netflix.zuul.exception.ZuulException",
    "message": "pre:AuthAccessFilter"
}

    RequestTemplate template = resolve(argv, mutable, varBuilder);
      if (metadata.queryMapIndex() != null) {
        // add query map parameters after initial resolve so that they take
        // precedence over any predefined values
        template = addQueryMapQueryParameters(argv, template);
      }
      if (metadata.headerMapIndex() != null) {
        template = addHeaderMapHeaders(argv, template);
      }

    private void parseHeaders(MethodMetadata md, Method method,
            RequestMapping annotation) {
        // TODO: only supports one header value per key
        if (annotation.headers() != null && annotation.headers().length > 0) {
            for (String header : annotation.headers()) {
                int index = header.indexOf('=');
                if (!header.contains("!=") && index >= 0) {
                    md.template().header(resolve(header.substring(0, index)),
                        resolve(header.substring(index + 1).trim()));
                }
            }
        }
    }

   @GetMapping(value = "/api/clusterManager/listTopics",
        headers = {"cache-control=no-cache", "username=wangyong@xxx.com"})
    TopicsResponse listTopics(@RequestParam("clusterName") String clusterName,
                              @RequestParam("clusterArea") String clusterArea);