Validate if string is an integer in Java

// w  w  w.  j  a  va 2s . co  m
public class Main {
  public static boolean checkIfNumber(String in) {
    try {
      Integer.parseInt(in);
    } catch (NumberFormatException ex) {
      return false;
    }
    return true;
  }

  public static void main(String[] args) {

    System.out.println(checkIfNumber("ABC"));
    System.out.println(checkIfNumber("123123123123123"));
  }
}