如何使用feign实现拦截器(RequestInterceptor)实现request转发呢?

Feign支持定义一个拦截器
     在请求前,进行相应的拦截
	 然后设置相应的请求头

实现思路:
    只需实现RequestInterceptor接口
	然后实现其apply方法即可

 
import com.java265.common.util.constant.HttpHeader;
import feign.RequestInterceptor;
import feign.RequestTemplate;
import lombok.extern.slf4j.Slf4j;
import org.springframework.stereotype.Component;
import org.springframework.web.context.request.RequestContextHolder;
import org.springframework.web.context.request.ServletRequestAttributes;
 
import javax.servlet.http.HttpServletRequest;
import java.util.Enumeration;
 
@Slf4j
@Component
public class FeignAddHeaderRequestInterceptor implements RequestInterceptor {
 
    @Override
    public void apply(RequestTemplate template) {
        ServletRequestAttributes attributes = (ServletRequestAttributes) RequestContextHolder
                .getRequestAttributes();
        if (attributes != null) {
            HttpServletRequest request = attributes.getRequest();
            Enumeration<String> headerNames = request.getHeaderNames();
            if (headerNames != null) {
                while (headerNames.hasMoreElements()) {
                    String name = headerNames.nextElement();
                    if (name.startsWith(HttpHeader.HTTP_HEADER_PREFIX) || name.startsWith(HttpHeader.HTTP_HEADER_PREFIX.toLowerCase())) {
                        String values = request.getHeader(name);
                        template.header(name, values);
                    }
                }
            }
        }else{
            template.header("error", "888");
        }
    }
}