title: Verify if String is hexadecimal
body: <p>I have a String like "09a" and I need a method to confirm if the text is hexadecimal. The code I've posted does something similar, it verifies that a string is a decimal number. I want to do the same, but for hexadecimal.</p>
  
  <pre><code>    private static boolean isNumeric(String cadena) {
      try {
          Long.parseLong(cadena);
          return true;
      } catch (NumberFormatException nfe) {
          JOptionPane.showMessageDialog(null,"Uno de los números, excede su capacidad.");
          return false;
      }
  }
  </code></pre>