Java by API/java.util/Timer — различия между версиями

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м (1 версия)
 
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Версия 17:43, 31 мая 2010

new Timer()

  
/*
 * Output:
Timer task executed.
Timer task executed.
Timer task executed.
Timer task executed.
Timer task executed. */
import java.util.Timer;
import java.util.TimerTask;
class MyTimerTask extends TimerTask {
  public void run() {
    System.out.println("Timer task executed.");
  }
}
public class MainClass {
  public static void main(String args[]) {
    MyTimerTask myTask = new MyTimerTask();
    Timer myTimer = new Timer();
    /*
     * Set an initial delay of 1 second, then repeat every half second.
     */
    myTimer.schedule(myTask, 1000, 500);
    try {
      Thread.sleep(5000);
    } catch (InterruptedException exc) {
    }
    myTimer.cancel();
  }
}





Timer: cancel()

  
/* From http://java.sun.ru/docs/books/tutorial/index.html */
/*
 * Copyright (c) 2006 Sun Microsystems, Inc. All Rights Reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * -Redistribution of source code must retain the above copyright notice, this
 *  list of conditions and the following disclaimer.
 *
 * -Redistribution in binary form must reproduce the above copyright notice,
 *  this list of conditions and the following disclaimer in the documentation
 *  and/or other materials provided with the distribution.
 *
 * Neither the name of Sun Microsystems, Inc. or the names of contributors may
 * be used to endorse or promote products derived from this software without
 * specific prior written permission.
 *
 * This software is provided "AS IS," without a warranty of any kind. ALL
 * EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND WARRANTIES, INCLUDING
 * ANY IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE
 * OR NON-INFRINGEMENT, ARE HEREBY EXCLUDED. SUN MIDROSYSTEMS, INC. ("SUN")
 * AND ITS LICENSORS SHALL NOT BE LIABLE FOR ANY DAMAGES SUFFERED BY LICENSEE
 * AS A RESULT OF USING, MODIFYING OR DISTRIBUTING THIS SOFTWARE OR ITS
 * DERIVATIVES. IN NO EVENT WILL SUN OR ITS LICENSORS BE LIABLE FOR ANY LOST
 * REVENUE, PROFIT OR DATA, OR FOR DIRECT, INDIRECT, SPECIAL, CONSEQUENTIAL,
 * INCIDENTAL OR PUNITIVE DAMAGES, HOWEVER CAUSED AND REGARDLESS OF THE THEORY
 * OF LIABILITY, ARISING OUT OF THE USE OF OR INABILITY TO USE THIS SOFTWARE,
 * EVEN IF SUN HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
 *
 * You acknowledge that this software is not designed, licensed or intended
 * for use in the design, construction, operation or maintenance of any
 * nuclear facility.
 */
import java.util.Timer;
import java.util.TimerTask;
/**
 * Simple demo that uses java.util.Timer to schedule a task to execute once 5
 * seconds have passed.
 */
public class Main {
  Timer timer;
  public Main(int seconds) {
    timer = new Timer();
    timer.schedule(new RemindTask(), seconds * 1000);
  }
  class RemindTask extends TimerTask {
    public void run() {
      System.out.println("Time"s up!");
      timer.cancel(); //Terminate the timer thread
    }
  }
  public static void main(String args[]) {
    System.out.println("About to schedule task.");
    new Main(5);
    System.out.println("Task scheduled.");
  }
}





Timer: scheduleAtFixedRate(TimerTask task, long delay, long period)

 
/* From http://java.sun.ru/docs/books/tutorial/index.html */
/*
 * Copyright (c) 2006 Sun Microsystems, Inc. All Rights Reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * -Redistribution of source code must retain the above copyright notice, this
 *  list of conditions and the following disclaimer.
 *
 * -Redistribution in binary form must reproduce the above copyright notice,
 *  this list of conditions and the following disclaimer in the documentation
 *  and/or other materials provided with the distribution.
 *
 * Neither the name of Sun Microsystems, Inc. or the names of contributors may
 * be used to endorse or promote products derived from this software without
 * specific prior written permission.
 *
 * This software is provided "AS IS," without a warranty of any kind. ALL
 * EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND WARRANTIES, INCLUDING
 * ANY IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE
 * OR NON-INFRINGEMENT, ARE HEREBY EXCLUDED. SUN MIDROSYSTEMS, INC. ("SUN")
 * AND ITS LICENSORS SHALL NOT BE LIABLE FOR ANY DAMAGES SUFFERED BY LICENSEE
 * AS A RESULT OF USING, MODIFYING OR DISTRIBUTING THIS SOFTWARE OR ITS
 * DERIVATIVES. IN NO EVENT WILL SUN OR ITS LICENSORS BE LIABLE FOR ANY LOST
 * REVENUE, PROFIT OR DATA, OR FOR DIRECT, INDIRECT, SPECIAL, CONSEQUENTIAL,
 * INCIDENTAL OR PUNITIVE DAMAGES, HOWEVER CAUSED AND REGARDLESS OF THE THEORY
 * OF LIABILITY, ARISING OUT OF THE USE OF OR INABILITY TO USE THIS SOFTWARE,
 * EVEN IF SUN HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
 *
 * You acknowledge that this software is not designed, licensed or intended
 * for use in the design, construction, operation or maintenance of any
 * nuclear facility.
 */
import java.awt.Toolkit;
import java.util.Timer;
import java.util.TimerTask;
/**
 * Schedule a task that executes once every second.
 */
public class Main {
  Toolkit toolkit;
  Timer timer;
  public Main() {
    toolkit = Toolkit.getDefaultToolkit();
    timer = new Timer();
    timer.scheduleAtFixedRate(new RemindTask(), 0, //initial delay
        1 * 1000); //subsequent rate
  }
  class RemindTask extends TimerTask {
    int numWarningBeeps = 3;
    public void run() {
      if (numWarningBeeps-- > 0) {
        long time = System.currentTimeMillis();
        if (time - scheduledExecutionTime() > 5) {
          return;
        }
        //If it"s not too late, beep.
        toolkit.beep();
        System.out.println("Beep!");
      } else {
        toolkit.beep();
        System.out.println("Time"s up!");
        //timer.cancel(); //Not necessary because we call System.exit
        System.exit(0); //Stops the AWT thread (and everything else)
      }
    }
  }
  public static void main(String args[]) {
    new Main();
  }
}





Timer: schedule(TimerTask task, Date firstTime, long period)

  
/*
 * Output:
Timer task executed.
Timer task executed.
Timer task executed.
Timer task executed.
Timer task executed. */
import java.util.Timer;
import java.util.TimerTask;
class MyTimerTask extends TimerTask {
  public void run() {
    System.out.println("Timer task executed.");
  }
}
public class MainClass {
  public static void main(String args[]) {
    MyTimerTask myTask = new MyTimerTask();
    Timer myTimer = new Timer();
    /*
     * Set an initial delay of 1 second, then repeat every half second.
     */
    myTimer.schedule(myTask, 1000, 500);
    try {
      Thread.sleep(5000);
    } catch (InterruptedException exc) {
    }
    myTimer.cancel();
  }
}