java中使用线程实现Timer（定时器）原理和源码

2007年06月21日 14:44:00

下载源码和示例

1 原理：启动一个线程来刷时间，缺点是不太精确，可能跟线程的优先级有关系。

会有0-10ms的误差。精确到0.1s是没有问题的。

package timer;

public class Timer ... {

private long interval;

// private boolean enabled;
private Task task;

private Clock clock;

public Timer(long _interval, Task _task) ...{
super();
this.interval = _interval;
// this.enabled = enabled;
this.task = _task;

clock = new Clock();
clock.start();

new Thread(new Runnable() ...{

public void run() ...{

boolean b = true;

while (b) ...{

//System.out.println(clock.getCurrTime());

if (interval >= clock.getCurrTime()) ...{

System.out.println(clock.getCurrTime());

task.doit();
clock.setCurrTime(0);

//clock.stop();

//System.out.println(clock.getCurrTime());

//b = false;
}
}

}

}).start();

}

public Task getTask() ...{
return task;
}

public long getInterval() ...{
return interval;
}

// public boolean isEnabled() {
// return enabled;
// }
// public void setEnabled(boolean enabled) {
// this.enabled = enabled;
// }
}

package timer;

public class Clock extends Thread ... {

private long oldTime;

private long currTime;

public Clock() ...{
oldTime = System.currentTimeMillis();
currTime = 0;
}

public long getCurrTime() ...{
return currTime;
}

@Override
public void run() ...{

while (true) ...{
currTime = System.currentTimeMillis() - oldTime;
}

}

public void setCurrTime(long currTime) ...{
this.currTime = currTime;
}

}

package timer;

public interface Task ... {

void doit();
}

package timer;

public class NewTask implements Task ... {

public void doit() ...{
System.out.println( System.currentTimeMillis() );
}

}

package timer;

public class Test ... {

/** *//**
* @param args
*/
public static void main(String[] args) ...{

Task task = new NewTask();
Timer t = new Timer(1000,task);

}

}

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