compare version numbers

public int (String version1, String version2) {
    String[] v1 = version1.split("\.");
    String[] v2 = version2.split("\.");
    int len = v1.length > v2.length ? v1.length : v2.length;
    for (int i = 0; i < len; ++i) {
        int num1 = i < v1.length ? Integer.parseInt(v1[i]) : 0;
        int num2 = i < v2.length ? Integer.parseInt(v2[i]) : 0;
        if (num1 < num2)
            return -1;
        else if (num1 > num2)
            return 1;
    }
    return 0;
}