stopwatch.java

利用BlueJ开发的一个类似小时候完的吃豆豆的小游戏

/*
 * StopWatch.java
 *
 * Created on September 25, 2003, 1:53 PM
 */

package cs101.util;

/**
 * A stopwatch for timing the execution of code. This class is intended to
 * provide aproximate time of execution to a resolution of single digit
 * miliseconds on most modern machines.  Estimates of cost on a dual
 * Athlon MP 2000+ machien yeild the following costs for the following methods
 * <ul>
 * <li><code>start()</code> takes aprox 0.000269 seconds
 * <li><code>stop()</code> takes aprox 0.000570 seconds
 * <li><code>reset()</code> takes aprox 0.000274 seconds
 * <li><code>elapsed()</code> takes aprox 0.000278 seconds (stopped)
 * <li><code>look()</code> takes aprox 0.006071 seconds(stopped)
 * <li><code>elapsed()</code> takes aprox 0.000285 seconds (running)
 * <li><code>look()</code> takes aprox 0.006209 seconds (running)
 * </ul>
 *
 * @author  Gus Heck ([e-mail])
 * @version $Id: StopWatch.java,v 1.1 2003/10/16 20:40:51 gus Exp $
 */
public class StopWatch {
    
    public static long MS_SEC = 1000l;
    public static long MS_MIN = 60000l;
    public static long MS_HOUR = 3600000l;
    
    private long started;
    private long startedFrom;
    private long stopped;
    private boolean running;
    
    /** Creates a new instance of StopWatch. */
    public StopWatch() {
        stop();
        reset();
    }
    
    /**
     * Start the stopwatch.
     */
    public void start() {
        running = true;
        started = System.currentTimeMillis();
    }
    
    /**
     * Stop the stopwatch.
     */
    public void stop() {
        stopped = System.currentTimeMillis();
        running = false;
        startedFrom = elapsed();
    }
    
    /**
     * Reset the stopwatch. It is perfectly legal and reasonable to
     * reset the stopwatch while it is still running. The elapsed time on
     * the stopwatch is set to 0 regardless.
     */
    public void reset() {
        stopped = started = System.currentTimeMillis();
        startedFrom = 0;
    }
    
    public long elapsed() {
        long time = System.currentTimeMillis();
        return ((running ? time : stopped) - started) 
                + startedFrom;
    }
    
    public String look() {
        StringBuffer elapsedTime = new StringBuffer();
        
        long time = elapsed();
        long ms = time % MS_SEC;
        long sec = (time % MS_MIN)/MS_SEC;
        long min = (time % MS_HOUR)/MS_MIN;
        long hour = time/MS_HOUR;
        
        elapsedTime.append(hour + " hours ");
        elapsedTime.append(min + " minutes ");
        elapsedTime.append(sec + "." + ms + " seconds ");
        elapsedTime.append("have elapsed.");
        
        return elapsedTime.toString();
    }
}