Valor para "int" reconhecimento de "double"

class Testing  
{  
  public static void main(String[] args)  
  {  
    System.out.println(isNumeric("123"));  
    System.out.println(isNumeric("123.45"));  
    System.out.println(isNumeric("$123"));  
    System.out.println(isNumeric("123x"));  
  }  
  public static boolean isNumeric(String str)  
  {  
    try  
    {  
      double d = Double.parseDouble(str);  
    }  
    catch(NumberFormatException nfe)  
    {  
      return false;  
    }  
    return true;  
  }  
}