content: package com.itheima.reggie.filter;
  
  import com.alibaba.fastjson.JSON;
  import com.itheima.reggie.common.BaseContext;
  import com.itheima.reggie.common.R;
  import lombok.extern.slf4j.Slf4j;
  import org.springframework.util.AntPathMatcher;
  
  import javax.servlet.*;
  import javax.servlet.annotation.WebFilter;
  import javax.servlet.http.HttpServletRequest;
  import javax.servlet.http.HttpServletResponse;
  import java.io.IOException;
  
  /**
   * 检查用户是否已经完成登录
   */
  @WebFilter(filterName = "loginCheckFilter",urlPatterns = "/*")
  @Slf4j
  public class LoginCheckFilter implements Filter{
      //路径匹配器，支持通配符
      public static final AntPathMatcher PATH_MATCHER = new AntPathMatcher();
  
      @Override
      public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
          HttpServletRequest request = (HttpServletRequest) servletRequest;
          HttpServletResponse response = (HttpServletResponse) servletResponse;
  
          //1、获取本次请求的URI
          String requestURI = request.getRequestURI();// /backend/index.html
  
          log.info("拦截到请求：{}",requestURI);
  
          //定义不需要处理的请求路径
          String[] urls = new String[]{
                  "/employee/login",
                  "/employee/logout",
                  "/backend/**",
                  "/front/**",
                  "/common/**",
                  "/user/sendMsg",
                  "/user/login"
          };
  
          //2、判断本次请求是否需要处理
          boolean check = check(urls, requestURI);
  
          //3、如果不需要处理，则直接放行
          if(check){
              log.info("本次请求{}不需要处理",requestURI);
              filterChain.doFilter(request,response);
              return;
          }
  
          //4-1、判断登录状态，如果已登录，则直接放行
          if(request.getSession().getAttribute("employee") != null){
              log.info("用户已登录，用户id为：{}",request.getSession().getAttribute("employee"));
  
              Long empId = (Long) request.getSession().getAttribute("employee");
              BaseContext.setCurrentId(empId);
  
              filterChain.doFilter(request,response);
              return;
          }
  
          //4-2、判断登录状态，如果已登录，则直接放行
          if(request.getSession().getAttribute("user") != null){
              log.info("用户已登录，用户id为：{}",request.getSession().getAttribute("user"));
  
              Long userId = (Long) request.getSession().getAttribute("user");
              BaseContext.setCurrentId(userId);
  
              filterChain.doFilter(request,response);
              return;
          }
  
          log.info("用户未登录");
          //5、如果未登录则返回未登录结果，通过输出流方式向客户端页面响应数据
          response.getWriter().write(JSON.toJSONString(R.error("NOTLOGIN")));
          return;
  
      }
  
      /**
       * 路径匹配，检查本次请求是否需要放行
       * @param urls
       * @param requestURI
       * @return
       */
      public boolean check(String[] urls,String requestURI){
          for (String url : urls) {
              boolean match = PATH_MATCHER.match(url, requestURI);
              if(match){
                  return true;
              }
          }
          return false;
      }
  }
  