目录

• Feign传递请求头信息
• 实现RequestInterceptor接口
• 注册配置
• Feign调用微服务传递header请求头

Feign传递请求头信息

在我之前的文章服务网关Spring Cloud Zuul中，将用户的登录id放在了请求头中传递给内部服务。

但是当内部服务之间存在feign调用时，那么请求头信息会在feign请求的时候传递吗？不会，请求的头信息和请求参数都不会进行传递。

但是我们可以通过通过实现RequestInterceptor接口,完成对所有的Feign请求,传递请求头和请求参数。

实现RequestInterceptor接口

import feign.RequestInterceptor;
import feign.RequestTemplate;
import org.springframework.web.context.request.RequestContextHolder;
import org.springframework.web.context.request.ServletRequestAttributes;
import javax.servlet.http.HttpServletRequest;
import java.util.Enumeration;
/**
 * Feign请求拦截器（设置请求头，传递登录信息）
 *
 * @author simon
 * @create 2018-09-07 9:51
 **/
public class FeignBasicAuthRequestInterceptor 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);
      }
    }
  }
}

这里只设置了请求头，如果想传递请求参数，可以参考如下代码：

public class FeignBasicAuthRequestInterceptor 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);
      }
    }
    Enumeration<String> bodyNames = request.getParameterNames();
      StringBuffer body =new StringBuffer();
      if (bodyNames != null) {
          while (bodyNames.hasMoreElements()) {
            String name = bodyNames.nextElement();
            String values = request.getParameter(name);
            body.append(name).append("=").append(values).append("&");
          }
      }
     if(body.length()!=0) {
        body.deleteCharAt(body.length()-1);
        template.body(body.toString());
        logger.info("feign interceptor body:{}",body.toString());
    }
  }
}

注册配置

package com.southgis.ibase.personalConfigure.config;
import com.southgis.ibase.utils.FeignBasicAuthRequestInterceptor;
import com.southgis.ibase.utils.FeignSpringFormEncoder;
import feign.RequestInterceptor;
import feign.codec.Encoder;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
/**
 * Feign配置注册（全局）
 *
 * @author simon
 * @create 2018-08-20 11:44
 **/
@Configuration
public class FeignSupportConfig {
  /**
   * feign请求拦截器
   *
   * @return
   */
  @Bean
  public RequestInterceptor requestInterceptor(){
    return new FeignBasicAuthRequestInterceptor();
  }
}

这个文件放在项目的扫描目录下，所有的feign调用都会使用此配置。如果只有某个feign调用则可以这样设置(但配置类不能在扫描目录下)：

@FeignClient(name = "organ",path = "/organ/OrganInfo",configuration = FeignSupportConfig.class)

Feign调用微服务传递header请求头

package com.chitic.module.core.config;
import feign.RequestInterceptor;
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;
import javax.servlet.http.HttpServletRequest;
import java.util.Enumeration;
 
@Configuration
public class FeignConfig {
    @Bean
    public RequestInterceptor headerInterceptor() {
        return template -> {
            ServletRequestAttributes attributes = (ServletRequestAttributes) RequestContextHolder.getRequestAttributes();
            if (null != attributes) {
                HttpServletRequest request = attributes.getRequest();
                Enumeration<String> headerNames = request.getHeaderNames();
                if (headerNames != null) {
                    while (headerNames.hasMoreElements()) {
                        String name = headerNames.nextElement();
                        String values = request.getHeader(name);
                        template.header(name, values);
                    }
                }
            }
        };
    }
}

需注意，feign调用时不能调用含有HttpServletResponse参数（比如常用的数据导出），以下就不能远程调用，目前没找到解决办法

以上为个人经验，希望能给大家一个参考，也希望大家多多支持。