java学习_Timer相关

1.Timer

Timer outTimer=null;

OutTimerTask outTimeTask=null;

//构造&初始化

outTimer = new Timer();

//开启超时

outTimeTask = new OutTimerTask();//每次都要构造新的TimerTask，TimerTask被cancle掉就不能再用了。

outTimer.schedule(outTimeTask, 40*1000);//40s超时

private class OutTimerTask extends TimerTask{
@Override
public void run() {
cancel();
//在这里做的就是超时处理
}
}

也可以写一个工具类：

import java.util.TimerTask;

public class OutTimerTask extends TimerTask {
public interface OutTimerTaskWatcher {
public void timeOutNotify(int id);
}

//data..
OutTimerTaskWatcher watcher;
int id=0;
//=end: data..

public OutTimerTask(OutTimerTaskWatcher watcher, int id) {
this.watcher = watcher;
this.id = id;
}

@Override
public void run() {
// TODO Auto-generated method stub
watcher.timeOutNotify(id);
}

}

2.AlarmManager(for android)

如果把一个timer放在Activity或Service里，时间长了很可能被干掉。

所以Android提供了AlarmManager，我们只需要注册

//闹钟到时后触发的动作，定义在这里。这是启动一个Service，也可以是BroadcastReceiver，详见ApiDemo
PendingIntent  mAlarmSender = PendingIntent.getService(MainActivity.this,
0, new Intent(MainActivity.this, TaskService.class), 0);

// Schedule the alarm!
AlarmManager am = (AlarmManager)getSystemService(ALARM_SERVICE);
am.setRepeating(AlarmManager.ELAPSED_REALTIME_WAKEUP,
firstTime, Common.TaskAlarmRate, mAlarmSender);

// And cancel the alarm.
AlarmManager am = (AlarmManager)getSystemService(ALARM_SERVICE);
am.cancel(mAlarmSender);

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