java timer定時器

*******監聽代碼*******
import javax.servlet.ServletContextEvent;
import javax.servlet.ServletContextListener;

public class ExecuteTaskListener implements ServletContextListener {

public void contextInitialized(ServletContextEvent event) {
new TimerManager();
} 

public void contextDestroyed(ServletContextEvent event) {

}

}


*******定時管理*******
import java.util.Calendar;
import java.util.Date;
import java.util.Timer;

public class TimerManager {
//執行間隔
private static final long PERIOD = 24 * 60 * 60 * 1000; 

public TimerManager() {
Calendar calendar = Calendar.getInstance();   

//設置每日00:00執行
calendar.set(Calendar.HOUR_OF_DAY, 00);
calendar.set(Calendar.MINUTE, 00);
calendar.set(Calendar.SECOND, 0);

Date date=calendar.getTime(); //定時任務的時間

//默認情況下執行日期小於當前日期立即執行;不需要立即執行，可以加一天
/*if (date.before(new Date())) {
date = this.addDay(date, 1);
}*/

Timer timer = new Timer();
ExecuteTimerTask task = new ExecuteTimerTask();

//執行定時任務
timer.schedule(task,date,PERIOD);
}

//提前或延期執行的日期 
public Date addDay(Date date, int number) {
Calendar calendar = Calendar.getInstance();
calendar.setTime(date);
calendar.add(Calendar.DAY_OF_MONTH, number);
return calendar.getTime();
}

}


*******定時執行內容*******
import java.util.TimerTask;

public class ExecuteTimerTask extends TimerTask {

public void run() {
try {
System.out.println("----定時器1開始運行-----");
} catch (Exception e) {
e.printStackTrace();
}
}

}


*******web.xml配置*******
<listener>
<listener-class>com.common.util.ExecuteTaskListener</listener-class>
</listener>