Fastest way to parse a YYYYMMdd date in Java [closed]

Answer 1

How about (but it would parse an invalid date without saying anything...):

public static void main(String[] args) throws Exception {
    char zero = '0';
    int yearZero = zero * 1111;
    int monthAndDayZero = zero * 11;
    String s = "20120405";
    int year = s.charAt(0) * 1000 + s.charAt(1) * 100 + s.charAt(2) * 10 + s.charAt(3) - yearZero;
    int month = s.charAt(4) * 10 + s.charAt(5) - monthAndDayZero;
    int day = s.charAt(6) * 10 + s.charAt(7) - monthAndDayZero;
}

Doing a quick and dirty benchmark with 100,000 iterations warm up and 10,000,000 timed iterations, I get:

• 700ms for your first method
• 350ms for your second method
• 10ms with my method.