Question

I’m trying to separate the hours, minutes, seconds, and milliseconds from an inputed time. Right now I have

public MillisTime(String str)
throws IllegalArgumentException {
    // Initialize values so that missing fields default to 0.
    int hours = 0, minutes = 0, seconds = 0, millis = 0;

    // Use Scanner class to parse the time string.
    // Catch InputMismatchException and rethrow IllegalArgumentException.
    Scanner scn = new Scanner(str);

    scn.useDelimiter(":");
    try {
        if (scn.hasNext()) hours = scn.nextInt();
        if (scn.hasNext()) minutes = scn.nextInt();
        if (scn.hasNext()) seconds = scn.nextInt();

        scn.useDelimiter(".");
        if (scn.hasNext()) millis = scn.nextInt();
    }
    catch (InputMismatchException ex) {
        throw new IllegalArgumentException(
                                           "String Input Mismatch Exception: " + str);
    }
    scn.close();
    this.setAllFields(hours, minutes, seconds, millis);
}

The input it is receiving is "16:5:7.009" and results in a String Input Mismatch Exception. If I take out the lines that look for the period and millis, and input something like 3:45 it works. How do I make this work to find : and .?

Answer 1

The exception occurs because with a delimiter of “:”, the subcomponents are {16, 5, 7.009}. 7.009 is not an integer so when you call scanner.nextInt() for the third time you get the exception.

Keep in mind that the delimiter scanner uses can be a regEx pattern, so it’s possible for the delimiter to be . OR : at the same time:

scanner.useDelimiter(Pattern.compile("[\\.:]");