转载自蝈蝈大神的文章,原文地址:Session过期验证
session过期判断的基本思想：用户登录成功后，将用户账号信息保存在session中，然后几乎每次执行命令都要经过过滤器，过滤器检查session中是否存在账号，若不存在，则返回登录页面，反之正常执行。
1、在web.xml添加
<filter><!-- 配置过滤器，用来检查session中是否存在用户登录账号信息 -->
<filter-name>ChkSessionFilter</filter-name>
<filter-class>com.um.core.filter.LoginFilter</filter-class>
</filter>
<filter-mapping>
<filter-name>ChkSessionFilter</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
<!-- 配置session过期时间 -->
<session-config>
<session-timeout>20</session-timeout>
</session-config>
<welcome-file-list>2、filter
package com.um.core.filter;
import java.io.IOException;
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;
import com.um.core.controller.BaseController;
/**
* 登录验证过滤器
*/
public class LoginFilter extends BaseController implements Filter {
/**
* 初始化
*/
public void init(FilterConfig fc) throws ServletException {
// FileUtil.createDir("d:/FH/topic/");
}
public void destroy() {
}
public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain)
throws IOException, ServletException {
HttpServletRequest request = (HttpServletRequest) req;
HttpServletResponse response = (HttpServletResponse) res;
String[] notFilter = new String[] { "userLogin","js","xml","css","demo","img","images","fonts","common","gateway","payCallback","toOrderPage","show_order"};//过滤字段、路径。。。。。。
String urlPath = request.getServletPath();
Boolean flg = false;
for (String url : notFilter) {
if ((urlPath.contains(url))) {
flg = true;
}
}
if(flg){
chain.doFilter(req, res);
}else{
HttpSession session = request.getSession();
String UID = (String) session.getAttribute("UID"); //登录成功将登录ID放入session中，这里将session取出对比
if (null == UID||"".equals(UID)) {
logger.warn("用户登录超时或未登录，请重新登录！");
java.io.PrintWriter out = response.getWriter();
out.println("<html>");
out.println("<script>");
out.println("window.open ('"+request.getContextPath()+"/login.jsp','_top')");
out.println("</script>");
out.println("</html>");
return;
}else {
chain.doFilter(req, res);
}
}
}
}