CareerCup

class MyTimer {

        private volatile Long startTime;
        private volatile Long endTime;  

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


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

        public Long duration() {
            if (startTime == null || endTime == null)
                return null;
            
            return (endTime - startTime);
        }

        public Long durationInSec() {
            Long d = duration();

            if (d == null)
                return null;
            
            return ( d/1000 );
        }

        public Long durationInMins() {
            Long d = durationInSec();
            
            if (d == null)
            return null;

            return ( d/60 );
        }

    }

public class Timer {

    
    private static final ThreadLocal<Integer> context = new ThreadLocal<Integer>();

    // it will start the timer 
    void static start(){
        long start = System.currentmillies();
        context.set(start);
    }
    
    // it will stop and return the duraton
    long  static stop(){
        long end = System.currentmillies();
        long start = context.get();
        return end-start; 
    }
}

public final class Timer {
	private final long START;
	
	private Timer() {
		this.START = System.currentTimeMillis();
	}
	
	public static Timer start() {
		return new Timer();
	}
		
	
	public long getDuration() {
		return System.currentTimeMillis() - START;
	}
}