sleepcommand.java

著名的uncle Bob的Agile software development的代码

public class SleepCommand implements Command
{
  private Command wakeupCommand = null;
  private ActiveObjectEngine engine = null;
  private long sleepTime = 0;
  private long startTime = 0;
  private boolean started = false;

  public SleepCommand(long milliseconds, ActiveObjectEngine e, Command wakeupCommand)
  {
    sleepTime = milliseconds;
    engine = e;
    this.wakeupCommand = wakeupCommand;
  }

  public void execute() throws Exception
  {
    long currentTime = System.currentTimeMillis();
    if (!started)
    {
      started = true;
      startTime = currentTime;
      engine.addCommand(this);
    }
    else if ((currentTime - startTime) < sleepTime)
    {
      engine.addCommand(this);
    }
    else
    {
      engine.addCommand(wakeupCommand);
    }
  }
}