Find The Longest Common Prefix Between Two Strings

public class LongestCommonPrefix {

    public static String lcp(String a, String b) {
        final int N = Math.min(a.length(), b.length());
        for (int i = 0; i < N; i++) {
            if (a.charAt(i) != b.charAt(i)) {
                return a.substring(0, i);
            }
        }
        return a.substring(0, N);
    }

    public static void main(String[] args) {
        final String a = args[0];
        final String b = args[1];
        System.out.println(lcp(a, b));
    }
}