public static boolean isIncorrect(String str) {
if (str == null || str == "" || str.length() == 0) {
return true;
}
for (int i = 0; i < str.length(); i++) {
char c = str.charAt(i);
if (!(c >= '0' && c <= '9') && !(c >= 'a' && c <= 'z')
&& !(c >= 'A' && c <= 'Z')) {
return true;
}
}
return false;
}
if (str == null || str == "" || str.length() == 0) {
return true;
}
for (int i = 0; i < str.length(); i++) {
char c = str.charAt(i);
if (!(c >= '0' && c <= '9') && !(c >= 'a' && c <= 'z')
&& !(c >= 'A' && c <= 'Z')) {
return true;
}
}
return false;
}