/**
*?

title:?


*?
description:?


*?
copyright:?copyright?(c)chen?meng?2005


*?
company:?陳盟?


*?
*? @author ?陳盟
*? @version ?1.0
*? @since ?2005-1-13?/?17:26:41
*/

package ?com.wellsoon.cttbj.vab.background;




import ?java.util.date;



import ?javax.servlet.servletcontextevent;
import ?javax.servlet.servletcontextlistener;




public ? class ?settleaccountlistener? implements ?servletcontextlistener?{

private ?java.util.timer?timer? = ? null ;




/* ?
*?@see?javax.servlet.servletcontextlistener#contextinitialized(javax.servlet.servletcontextevent)
*/
public ? void ?contextinitialized(servletcontextevent?event)?{
date?taskrun? = ? null ;

// ?todo?auto-generated?method?stub
taskrun? = ? new ?date();
timer? = ? new ?java.util.timer( true );
event.getservletcontext().log(定時器已啟動);?
/ 在這里每隔一分鐘輪詢一次出帳任務,如果任務間隔比較大的話建議把這個值設的大一點,但此設置值將間接影響可設定的觸發精度.
timer.schedule( new ?settleaccounttask(),? 0 ,? 60 * 1000 );? /
event.getservletcontext().log(已經添加任務調度表);



}



/* ?
*?@see?javax.servlet.servletcontextlistener#contextdestroyed(javax.servlet.servletcontextevent)
*/
public ? void ?contextdestroyed(servletcontextevent?event)?{
// ?todo?auto-generated?method?stub
timer.cancel();
event.getservletcontext().log(定時器銷毀);



}



}



接著來看settleaccounttask的實現:



/**
*?

title:?


*?
description:?


*?
copyright:?copyright?(c)chen?meng?2005


*?
company:?陳盟?


*?
*? @author ?陳盟
*? @version ?1.0
*? @since ?2005-1-13?/?17:35:55
*/



package ?com.wellsoon.cttbj.vab.background;



import ?java.util.calendar;
import ?java.util.date;
import ?java.util.timertask;




public ? class ?settleaccounttask? extends ?timertask?{



private ? static ? boolean ?isrunning? = ? false ;
private ? static ? long ?dotaskmillis? = ? 0l ;



public ? void ?run()?{
system.out.println(dotaskmillis);?
// 下面兩個值代表每月的哪一天幾點進行實際任務操作.可以通過數據庫查詢獲得
int ?c_schedule_date? = ? 10 ;
int ?c_schedule_hour? = ? 4 ;
calendar?cal? = ?calendar.getinstance();
// 如果任務量很大,在下次輪詢時仍在執行上次輪詢的任務,則跳過本次執行,直接錯過.
if ?( ! isrunning)?{
// 如果當前系統時間的day_of_month和hour_of_day不滿足以下條件,則跳過實際操作.
if ?(c_schedule_date? == ?cal.get(calendar.day_of_month)?＆＆?c_schedule_hour? == ?cal.get(calendar.hour_of_day))?{
// 如果上次執行任務的時間距此次輪詢時間間隔太短,則跳過實際操作.
if ((dotaskmillis? 2 * 60 * 60 * 1000 )? < ?cal.gettimeinmillis())?{
// ?詳細任務
isrunning? = ? true ;
system.out.println(執行出帳操作);
dotaskmillis? = ?cal.gettimeinmillis();
system.out.println(dotaskmillis);
isrunning? = ? false ;
}
}
}? else ?{
system.out.println(錯過);
}
}
}