Calculate duration in miliseconds and convert to datetime

Question

I have two variables - time when activity starts (currentTime) and time when the button is clicked (endTime). These variables have values in milliseconds (System.currentTimeMillis()). I use them in Layout so I convert these values to DateFormat "HH:mm:ss".

I want to calculate duration (durationTime) between currentTime and endTime and convert it to datetime. Look please to my code:

public class MainActivity extends Activity {

            long currentTime_ms, endTime_ms;
            SimpleDateFormat sdf = new SimpleDateFormat("HH:mm:ss");

            @Override
            public void onCreate(Bundle savedInstanceState) {
                super.onCreate(savedInstanceState);
                setContentView(R.layout.activity_main);

                currentTime_ms = System.currentTimeMillis();
                Date currentTime = new Date(currentTime_ms);
                currentTime_textView.setText(sdf.format(currentTime));
            }

            public void btnOk_onClick(View v) {

                endTime_ms = System.currentTimeMillis();
                Date endTime = new Date(endTime_ms);
                Date durationTime = new Date(endTime_ms - currentTime_ms);
            }

        }

Finally I've got wrong duration. (For example I click on Button after 2 second and get durationTime 02:00:02).

Can you help me to fix the code? Or maybe there are other methods for time calculation?

First of all you have bad onClickListener. When You have activity, you have to set the listener on button: `Button btn = (Button)findViewById(R.id.button_id); btn.setOnClickListener(new OnClickListener{ @Override public void onClick(){ //code here } }` — Mariusz Brona, Oct 18 '14 at 20:36
Ok, thanks for advice. I will use OnClickListener. And what about time calculations? — Aleksey Kurkov, Oct 18 '14 at 20:43
It should be really simple. You have the global variables so its good. Next just look into it for example: http://stackoverflow.com/questions/21285161/android-difference-between-two-dates — Mariusz Brona, Oct 18 '14 at 20:45

score 0 · Answer 1 · answered Oct 19 '14 at 08:22

You can get current time with SystemClock.elapsedRealtime();

Take two timestamps (for beginning and ending) and then you'll have two different longs.

Calculate the difference between them, and call this function, which will return the String that you are looking for. You can customize it as you want!!

public String toText(long difference) {
    DecimalFormat df = new DecimalFormat("00");

    int remaining = (int) (difference % (3600 * 1000));

    int minutes = (int) (remaining / (60 * 1000));
    remaining = (int) (remaining % (60 * 1000));

    int seconds = (int) (remaining / 1000);
    remaining = (int) (remaining % (1000));

    int cents = (int) (((int) time % 1000) / 10);

    String text = "";
    text += df.format(minutes) + ":";
    text += df.format(seconds) + ":";
    text += df.format(cents);
    return text;
}

In your case, this should return "00:02:00": 0 minutes, 2 seconds, 0 cents.

I hope this would helps!!

Calculate duration in miliseconds and convert to datetime

1 Answers1