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Is there a stopwatch in Java?


Is there a stopwatch in Java?
On Google I only found code of stopwatches that don't work - they always return 0 milliseconds.

This code I found doesn't work and I don't see why.

public class StopWatch {
  
  private long startTime = 0;
  private long stopTime = 0;
  private boolean running = false;
  
  
  public void start() {
    this.startTime = System.currentTimeMillis();
    this.running = true;
  }
  
  
  public void stop() {
    this.stopTime = System.currentTimeMillis();
    this.running = false;
  }
  
  
  //elaspsed time in milliseconds
  public long getElapsedTime() {
    long elapsed;
    if (running) {
      elapsed = (System.currentTimeMillis() - startTime);
    } else {
      elapsed = (stopTime - startTime);
    }
    return elapsed;
  }
  
  
  //elaspsed time in seconds
  public long getElapsedTimeSecs() {
    long elapsed;
    if (running) {
      elapsed = ((System.currentTimeMillis() - startTime) / 1000);
    } else {
      elapsed = ((stopTime - startTime) / 1000);
    }
    return elapsed;
  }
}

Solution

  • You'll find one in

    http://commons.apache.org/lang/

    It's called

    org.apache.commons.lang.time.StopWatch
    

    But it roughly does the same as yours. If you're in for more precision, use

    System.nanoTime()
    

    See also this question here:

    Time measuring overhead in Java