public class Stopwatch {
    
    private double startTime;
    
    public Stopwatch() {
        this.reset();
    }
    
    public double read() {
        return System.currentTimeMillis() - startTime;
    }
    
    public double readSeconds() {
        return this.read() / 1000;
    }
    
    public void reset() {
        startTime = System.currentTimeMillis();
    }
    
}