public void test() {

    Stirng t1 = "10:30 AM"; // 12-hours format
    Stirng t2 = "11:30 AM"; // 12-hours format
            <or>
    Stirng t1 = "10:30"; // 24-hours format
    Stirng t2 = "11:30"; // 24-hours format

    if(t1.before(t2)) {
        System.out.println(t1 + " is before of " + t2);
    }
}

SimpleDateFormat formatter = new SimpleDateFormat("HH:mm");
Date time =  formatter.parse("11:30");

if (new DateTime(2012, 9, 15, 10, 30).compareTo(new DateTime(2012, 9, 15, 11, 30) < 0) {
    // first is before second date
}

if (new LocalTime(10, 30).compareTo(new LocalTime(11, 30) < 0) {
    // first time is before second time
}