Check if time is inbetween timerange in Android

Question

I am trying to check if the current time is in the range of a specified range. I made a method to check this, but it doesn't work. I'm not sure why not and how to get it to work.

private Calendar fromTime;
private Calendar toTime;
private Calendar currentTime;

public boolean checkTime(String time) {
    try {
        String[] times = time.split("-");
        String[] from = times[0].split(":");
        String[] until = times[1].split(":");

        fromTime = Calendar.getInstance();
        fromTime.set(Calendar.HOUR, Integer.valueOf(from[0]));
        fromTime.set(Calendar.MINUTE, Integer.valueOf(from[1]));

        toTime= Calendar.getInstance();
        toTime.set(Calendar.HOUR, Integer.valueOf(until[0]));
        toTime.set(Calendar.MINUTE, Integer.valueOf(until[1]));

        currentTime = Calendar.getInstance();       
        currentTime.set(Calendar.HOUR, Calendar.HOUR_OF_DAY);
        currentTime.set(Calendar.MINUTE, Calendar.MINUTE);
        if(currentTime.after(fromTime) && currentTime.before(toTime)){
            return true;
        }
     } catch (Exception e) {
         return false;
     }
    return false;
}

I am trying to test it like this:

if(checkTime("06:00-19:00")){
    inRange = true;
}

The NPE is gone, but it's still not calculating if the time is in the range of fromTime to toTime. Any help is very much appreciated!

Answer 1

Initialize variables and change the return type of your method to boolean.

private Calendar fromTime;
private Calendar toTime;
private Calendar currentTime;

public boolean checkTime(String time) {
try {
    String[] times = time.split("-");
    String[] from = times[0].split(":");
    String[] until = times[1].split(":");

    fromTime = Calendar.getInstance();
    fromTime.set(Calendar.HOUR_OF_DAY, Integer.valueOf(from[0]));
    fromTime.set(Calendar.MINUTE, Integer.valueOf(from[1]));

    toTime = Calendar.getInstance();
    toTime.set(Calendar.HOUR_OF_DAY, Integer.valueOf(until[0]));
    toTime.set(Calendar.MINUTE, Integer.valueOf(until[1]));

    currentTime = Calendar.getInstance();
    currentTime.set(Calendar.HOUR_OF_DAY, Calendar.HOUR_OF_DAY);
    currentTime.set(Calendar.MINUTE, Calendar.MINUTE);
    if(currentTime.after(fromTime) && currentTime.before(toTime)){
        return true;
    }
    } catch (Exception e) {
        return false;
    }
    return false;
}

Answer 2

You have not initialized toTime and fromTime objects before using them. So better call toTime = Calendar.getInstance(); before.

private Calendar fromTime;
private Calendar toTime;
private Calendar currentTime;

public boolean checkTime(String time) {
try {
    String[] times = time.split("-");
    String[] from = times[0].split(":");
    String[] until = times[1].split(":");

    fromTime = Calendar.getInstance();
    fromTime.set(Calendar.HOUR, Integer.valueOf(from[0]));
    fromTime.set(Calendar.MINUTE, Integer.valueOf(from[1]));

    toTime = Calendar.getInstance();
    toTime.set(Calendar.HOUR, Integer.valueOf(until[0]));
    toTime.set(Calendar.MINUTE, Integer.valueOf(until[1]));

    currentTime = Calendar.getInstance();
    currentTime.set(Calendar.HOUR, Calendar.HOUR_OF_DAY);
    currentTime.set(Calendar.MINUTE, Calendar.MINUTE);
    if(currentTime.after(fromTime) && currentTime.before(toTime)){
        return true;
    }
    } catch (Exception e) {
        return false;
    }
    return false;
}