timerservlet.java

oa办公系统

package cn.jx.ecjtu.oa.servlets;

import java.io.IOException;
import java.util.Timer;
import java.util.TimerTask;

import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import cn.jx.ecjtu.oa.services.RefreshTask;
import cn.jx.ecjtu.oa.services.TimeSaveTask;
/**
 * @todo: 这是一个用来更新维护appliaction中的在线人员列表的 servlet.随web应用启动而启动,直到这个应用退出 (更新appliaction中在线人员列表的在线时间和维护在线人员数量)
 * @author yuankai
 * @version $Revision: 1.2 $
 * @since 1.0
 */
public class TimerServlet extends HttpServlet {
	private static final long serialVersionUID = 6283044987900458377L;
	private Timer timer=null;
    private RefreshTask task =null;

    public void destroy() {
	super.destroy(); // Just puts "destroy" string in log
	//销毁定时器
	if(null!=timer)
	    timer.cancel();
    }

    /**
     * The doGet method of the servlet. <br>
     *
     * This method is called when a form has its tag value method equals to get.
     * 
     * @param request the request send by the client to the server
     * @param response the response send by the server to the client
     * @throws ServletException if an error occurred
     * @throws IOException if an error occurred
     */
    public void doGet(HttpServletRequest request, HttpServletResponse response)
	    throws ServletException, IOException {
          this.doPost(request, response);
    }

    /**
     * The doPost method of the servlet. <br>
     *
     * This method is called when a form has its tag value method equals to post.
     * 
     * @param request the request send by the client to the server
     * @param response the response send by the server to the client
     * @throws ServletException if an error occurred
     * @throws IOException if an error occurred
     */
    public void doPost(HttpServletRequest request, HttpServletResponse response)
	    throws ServletException, IOException {
    }

    /**
     * Initialization of the servlet. <br>
     *
     * @throws ServletException if an error occurs
     */
    public void init() throws ServletException {
	ServletContext context=this.getServletContext();
	
	// (true为用定时间刷新缓存)    
	String start_app_task= getInitParameter("start_task");    
	
	// 定时刷新时间(分钟)    
	long app_delay = Long.parseLong(getInitParameter("delay"));    

	// 启动定时器 在线列表内存更新    
	if(start_app_task.equals("true")){    
	    timer = new Timer(true);    
	    task = new RefreshTask(context);    
	    timer.schedule(task, app_delay * 60 * 1000, app_delay * 60 * 1000);    
	}
 
    }

}