How do I measure time elapsed in Java? [duplicate]

Answer 1

Which types to use in order to accomplish this in Java?

Answer: long

public class Stream {
    public long startTime;
    public long endTime;

    public long getDuration() {
        return endTime - startTime;
    }
    // I  would add
    public void start() {
        startTime = System.currentTimeMillis();
    }
    public void stop() {
         endTime = System.currentTimeMillis();
     }
}

Usage:

  Stream s = .... 

  s.start();

  // do something for a while 

  s.stop();

  s.getDuration(); // gives the elapsed time in milliseconds. 

That's my direct answer for your first question.

For the last "note" I would suggest you to use Joda Time. It contains an interval class suitable for what you need.