Compute times in Java eg. 1900 1710 = 110 mins

If you've just got integers, and you don't care about validation, you can do it all without touching time parts at all:

public int getMinutesBetween(int time1, int time2) {
    // Extract hours and minutes from compound values, which are base-100,
    // effectively.
    int hours1 = time1 / 100;
    int hours2 = time2 / 100;
    int minutes1 = time1 % 100;
    int minutes2 = time2 % 100;
    // Now we can perform the arithmetic based on 60-minute hours as normal.
    return (hours2 - hours1) * 60 + (minutes2 - minutes1);
}

However, I'd strongly recommend that you use more appropriate representations - these aren't just normal int values... they're effectively "time of day" values, so LocalTime (in either Joda Time or Java 8's java.time) is the most appropriate representation, IMO.