code: public boolean isDouble(String value) {
          boolean result = true;
          try {
              Double.valueOf(value);
          } catch (NumberFormatException e) {
              result = false;
          }
          return result;
      }
docs: Check whether the given value is a valid numeric value that can be
  converted to an {@link Double}.
  
  @param value The associated value to test
  
  @return <code>true</code> The value is a valid double,
  <code>false</code> otherwise
  
  @see #convertStringToDouble(String)
  @see Double#valueOf(String)