package com.whyc.filter;

import com.whyc.pojo.User;
import com.whyc.util.ShiroUtil;

import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpSession;
import java.io.IOException;

/**
 * 账号同时登录只能1个
 */
@WebFilter(urlPatterns = "/*",filterName = "kickedOutFilter")
public class KickedOutFilter implements Filter {

    @Override
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
        HttpSession session = ((HttpServletRequest) request).getSession();
        //如果是登录,则不进行Session对比,放行
        if(!((HttpServletRequest) request).getRequestURI().contains("login")) {
            User user = ShiroUtil.getUser();
            if (user.getId() != 0) {
                System.out.println("Filter过滤器中获取到的当前Session的SessionId为:" + session.getId());
                if (!request.getServletContext().getAttribute(user.getName()).equals(session.getId())) {
                    //如果当前Session所对应的SessionId与全局中用户对应的SessionId不一致,则清除当前Session
                    session.invalidate();
                    response.setContentType("text/html;charset=utf-8");
                    response.getWriter().write("<script language='javascript' type='text/javascript'>alert('账号已经在其他地方登录,请重新登录');self.location='login.html'</script> ");
                    return;
                }
            }
        }

        chain.doFilter(request,response);
    }
}