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 org.apache.shiro.SecurityUtils;
import org.apache.shiro.subject.Subject;import cn.zsmy.constant.Constant;
import cn.zsmy.entity.User;/** * session超时过滤 *  * @date 2016-10-20*/
public class SessionFilter implements Filter {  @Override  public void init(FilterConfig filterConfig) throws ServletException {  }  @Override  public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException,  ServletException {  HttpServletRequest httpServletRequest = (HttpServletRequest) request;  HttpServletResponse httpServletResponse = (HttpServletResponse) response;  //只过滤了ajax请求时session超时if (httpServletRequest.getHeader("x-requested-with") != null  && httpServletRequest.getHeader("x-requested-with").equalsIgnoreCase("XMLHttpRequest")) {  Subject subject = SecurityUtils.getSubject();User user = (User) subject.getPrincipal();if(user == null){Constant.MY_LOG.debug("filter：sessionstatus timeout！");//如果是ajax请求响应头会有，x-requested-with  httpServletResponse.setHeader("sessionstatus", "timeout");//在响应头设置session状态  return;  }} chain.doFilter(request, response);  }  @Override  public void destroy() {  }  } 

<!--session超时过滤处理 --><filter><filter-name>sessionFilter</filter-name><filter-class>cn.zsmy.palmdoctor.filter.SessionFilter</filter-class></filter><filter-mapping><filter-name>sessionFilter</filter-name><!-- <url-pattern>/*</url-pattern> --><url-pattern>*.do</url-pattern></filter-mapping>

<c:set var="appPath" value="<%=request.getContextPath()%>"/>

<script type="text/javascript">
$(function(){$.ajaxSetup ({cache: false, //关闭AJAX缓存async:false, //同步请求contentType:"application/x-www-form-urlencoded;charset=utf-8",  complete:function(XMLHttpRequest,textStatus){  //通过XMLHttpRequest取得响应头，sessionstatus，  var sessionstatus=XMLHttpRequest.getResponseHeader("sessionstatus");   if(sessionstatus=="timeout"){  alert("由于您长时间未操作,登录已失效,请重新登录");parent.location.href = "${appPath}/login.do";}  }  });
});
</script>