StopWatch - simple stopwatch-thingie

StopWatch.java

import java.util.Date;
import java.util.concurrent.TimeUnit;

/**
 * Simple Stopwatch implementation in order to measure ..things.
 *
 * @author <a href="mailto:[email protected]">Vegard Aasen</a>
 * @since 8:30 PM
 */
public final class StopWatch {

    private long start = 0L;
    private long stop = 0L;
    private boolean running = false;
    private String watchName = "Casio Stopwatch";

    public StopWatch() {
    }

    public void start() {
        start = System.currentTimeMillis();
        running = true;
    }

    public void stop() {
        stop = System.currentTimeMillis();
        running = false;
    }

    public void reset() {
        start = 0L;
        stop = 0L;
        running = false;
    }

    public long elapsedTime(final TimeUnit unit) {
        final TimeUnit u = TimeUnit.MILLISECONDS;
        return u.convert(elapsedTime(), unit);
    }

    public boolean isActive() {
        return running;
    }

    public long elapsedTime() {
        if (start > 0L && running) {
            return System.currentTimeMillis() - start;
        } else if (start > 0L && !running) {
            return stop - start;
        }
        return 0L;
    }

    public long getTotalTimeMillis() {
        if (start > 0L && stop > 0L) {
            return stop - start;
        }
        throw new IllegalStateException("Either stop or start have not yet been triggered. Take care of that first.");
    }

    public Date getStarted() {
        if (start > 0) {
            return new Date(start);
        }
        return null;
    }

    public Date getStopped() {
        if (isActive()) {
            throw new IllegalStateException("Stopwatch is still running.");
        }
        if (stop > 0) {
            return new Date(stop);
        }
        return null;
    }

    public String getWatchName() {
        return watchName;
    }

    public void setWatchName(final String name) {
        watchName = name;
    }

    @Override
    public String toString() {
        return String.format("%s started running %s, and completed %s. Time so far %sms.",
                getWatchName(),
                (start > 0) ? new Date().toString() : "**Not started yet**",
                (stop > 0) ? new Date().toString() : "**Still active**",
                isActive() ? elapsedTime() : getTotalTimeMillis());
    }

}