A simple timer Service.

Web-timeservice is used for timed invocation (triggering) applications, EJB2.1 also provides timerservice, but some application servers are not supported and some do not use EJBS at all. So I wrote a simple timerserivce.

public class Timerservice


{


public static final long p = 1000*60*60;


Timer timer = new timer (false);


Timerschedule schedule = null;


public Timerservice ()


　{


　}


public void Start () throws Exception


　{


schedule = new Timerschedule ();


Schedule.addtimerjob (New Sometimerjob ());


//add Other job here


Timer.schedule (schedule,0,p);


　}


public void Stop () throws Exception


　{


Timer.cancel ();


　}


}


//contains multiple timerjob, and every time it is taken out to see if the call


public class Timerschedule extends TimerTask


{


Private List = new ArrayList ();


public Timerschedule ()


　{}


public void Addtimerjob (timerjob job)


　{


list.add (Job);


　}


public void Run ()


　{


Date now = Calendar.getinstance (). GetTime ();


Date next = null;


for (int i=0;i<list.size (); i++)


　　{


timerjob job = (timerjob) list.get (i);


next = Job.getnextexedate ();


if (isequals (now,next))


　　　{


Job.execute ();


　　　}


　　}


　}


/**


* Compare whether two time difference is less than TIMERSERVICE.P (one cycle)


* @param now


* @param next


* @return


*/


Private Boolean isequals (Date now,date next)


{


Long time = Next.gettime ()-now.gettime ();


if (Time <= timerservice.p &amp;&amp; time >= 0)


　{


return true;


　}


Else


　{


return false;


　}


}


public boolean cancel ()


{


return true;


}


}


//This interface describes how to complete the timertask, please refer to timerjobexample


Interface Timerjob


{


public void execute ();


public Date getnextexedate ();


}


/**


* This example is used to demonstrate how to complete the Tiemrjob


* This example function is called at one o'clock in the morning every day of the


*/


public class Timerjobexample implements Timerjob


{


Calendar nextdate = null;


public timerjobexample ()


　{


nextdate = Calendar.getinstance ();


Nextdate.add (calendar.day_of_month,1);


//will set the call time is (the next day) every 1 o'clock in the morning


Nextdate.set (calendar.hour_of_day,1);


　}


public void execute ()


　{


Nextdate.add (calendar.day_of_month,1);


Nextdate.set (calendar.hour_of_day,1);


callfunction ();


　}


public Date getnextexedate ()


　{　


return Nextdate.gettime ();


　}


private void CallFunction ()


　{


System.out.println ("Timerjobexample call EJB funcation:" +new Date ());


　}


}