java-How to implement Timer function

java-How to implement Timer function

2004-11-8
Author:meanson Wang
Email:meansonw@hotmail.com
Date:2004-11-8
java-How to implement Timer function

1.listener class
Package timer;

Import Java.util.TimerTask;
Import Java.util.Timer;
Import javax.servlet.*;

public class Remindlistener implements Servletcontextlistener {
Private Java.util.Timer Timer = null;
public void contextinitialized (Servletcontextevent sce) {
Timer = new Java.util.Timer (true);
Sce.getservletcontext (). log (new java.util.Date () + "Timer start up!");
Timer.schedule (New Remindtask (), 0,1*60*1000);//1 minute roll
Sce.getservletcontext (). log (new java.util.Date () + "Schedule loaded!");
}
public void contextdestroyed (Servletcontextevent sce) {
Timer.cancel ();
Sce.getservletcontext (). log (new java.util.Date () + "Timer destroyed!");
}

}

2.Task class
Package timer;

Import Java.util.TimerTask;
Import Java.util.Calendar;

public class Remindtask extends timertask{
private static final int c_schedule_hour = 15;
private static Boolean isrunning = false;
Public Remindtask () {

}
public void Run () {
Calendar cal = Calendar.getinstance ();
if (!isrunning) {
if (C_schedule_hour = = Cal.get (calendar.hour_of_day)) {
IsRunning = true;
System.out.println (New Java.util.Date () + "task start");
TODO for example
int i = 0;
while (i++ < 10) {
System.out.println (New Java.util.Date () + "Done!task" + i + "/" + 10);
}
IsRunning = false;
System.out.println (New Java.util.Date () + "all Task done!");
}
}
Else
{
System.out.println (New Java.util.Date () + "Task existed!");
}
}
}

3.loadonstart in Web.xml
<listener>
<listener-class>timer. Remindlistener</listener-class>
</listener>

4.restart Server