【阳哥专栏】javaweb中用Filter过滤失效的Session - 黑马程序员技术交流社区

package com.itheima.common;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
public class LoginFilter implements Filter {
public void destroy() {
// TODO Auto-generated method stub
}
public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain) throws IOException, ServletException {
// TODO Auto-generated method stub
HttpServletRequest request = (HttpServletRequest) req;
HttpServletResponse response = (HttpServletResponse) res;
HttpSession session = request.getSession();
// 如果session不为空，则可以浏览其他页面
String url = request.getServletPath();
System.out.println(url);
//这里判断目录，后缀名，当然也可以写在web.xml中，用url-pattern进行拦截映射
if ((!request.getServletPath().equals("/login.action"))
&& (!request.getServletPath().equals("/login.jsp"))
&& (!request.getServletPath().equals("/relogin.jsp"))
&& (!request.getServletPath().equals("/jquery-1.8.0.min.js"))) {
System.out.println(request.getServletPath());
if (session.getAttribute("userInfo") == null) {
session.invalidate();
response.setContentType("text/html;charset=gb2312");
PrintWriter out = response.getWriter();
out.println("<script language='javascript' type='text/javascript'>");
out.println("alert('由于你长时间没有操作,导致Session失效!请你重新登录!');window.location.href='" + request.getContextPath() + "/relogin.jsp'");
out.println("</script>");
} else {
chain.doFilter(request, response);
}
} else {
chain.doFilter(request, response);
}
}
public void init(FilterConfig arg0) throws ServletException {
// TODO Auto-generated method stub
}
}

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