这篇文章主要介绍了SpringBoot+SpringCloud实现登录用户信息在微服务之间的传递,文中通过示例代码介绍的非常详细，对大家的学习或者工作具有一定的参考学习价值,需要的朋友可以参考下

实现思路：

1：准备一个ThreadLocal变量，供线程之间共享。

2：每个微服务对所有过来的Feign调用进行过滤，然后从请求头中获取User用户信息，并存在ThreadLocal变量中。

3：每个微服务在使用FeignClient调用别的微服务时，先从ThreadLocal里面取出user信息，并放在request的请求头中。

4：封装为一个注解，在启动类上标记即可。

代码样例：

1：ThreadLocal工具类 ：UserInfoContext

package com.test.domi.common.system;

import com.test.domi.dao.UserInfo;

public class UserInfoContext {
  private static ThreadLocal<UserInfo> userInfo = new ThreadLocal<UserInfo>();
  public static String KEY_USERINFO_IN_HTTP_HEADER = "X-AUTO-FP-USERINFO";

  public UserInfoContext() {
  }

  public static UserInfo getUser(){
    return (UserInfo)userInfo.get();
  }

  public static void setUser(UserInfo user){
    userInfo.set(user);
  }
}

2：准备承载用户信息的userInfo实体类（代码略）

3：编写拦截器 ： TransmitUserInfoFeighClientIntercepter

package com.test.domi.config;

import com.alibaba.fastjson.JSON;
import com.test.domi.common.system.UserInfoContext;
import com.test.domi.dao.UserInfo;
import feign.RequestInterceptor;
import feign.RequestTemplate;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.io.UnsupportedEncodingException;
import java.net.URLDecoder;

public class TransmitUserInfoFeighClientIntercepter implements RequestInterceptor {

  private static final Logger log = LoggerFactory.getLogger(TransmitUserInfoFeighClientIntercepter.class);
  public TransmitUserInfoFeighClientIntercepter() {
  }

  @Override
  public void apply(RequestTemplate requestTemplate) {
    //从应用上下文中取出user信息，放入Feign的请求头中
    UserInfo user = UserInfoContext.getUser();
    if (user != null) {
      try {
        String userJson = JSON.toJSONString(user);
        requestTemplate.header("KEY_USERINFO_IN_HTTP_HEADER",new String[]{URLDecoder.decode(userJson,"UTF-8")});
      } catch (UnsupportedEncodingException e) {
        log.error("用户信息设置错误",e);
      }
    }
  }
}

4：编写过滤器：TransmitUserInfoFilter

package com.test.domi.config;

import com.alibaba.fastjson.JSON;
import com.test.domi.common.system.UserInfoContext;
import com.test.domi.dao.UserInfo;
import org.apache.commons.lang.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import javax.servlet.*;
import javax.servlet.http.HttpServletRequest;
import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.net.URLDecoder;

public class TransmitUserInfoFilter implements Filter {

  private static final Logger log = LoggerFactory.getLogger(TransmitUserInfoFeighClientIntercepter.class);
  public TransmitUserInfoFilter() {
  }
  @Override
  public void init(FilterConfig filterConfig) throws ServletException {
  }
  @Override
  public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
    this.initUserInfo((HttpServletRequest)request);
    chain.doFilter(request,response);
  }

  private void initUserInfo(HttpServletRequest request){
    String userJson = request.getHeader("KEY_USERINFO_IN_HTTP_HEADER");
    if (StringUtils.isNotBlank(userJson)) {
      try {
        userJson = URLDecoder.decode(userJson,"UTF-8");
        UserInfo userInfo = (UserInfo) JSON.parseObject(userJson,UserInfo.class);
        //将UserInfo放入上下文中
        UserInfoContext.setUser(userInfo);
      } catch (UnsupportedEncodingException e) {
        log.error("init userInfo error",e);
      }
    }
  }

  @Override
  public void destroy() {
  }
}