private String doubleToString(double input,boolean isInteger){
  if (Double.isNaN(input)) {
    return null;
  }
  if (isInteger && input == (int)input) {
    return "" + (int)input;
  }
 else {
    return "" + input;
  }
}

private String doubleToString ( double input , boolean isInteger ) { if ( Double . isNaN ( input ) ) { return null ; } if ( isInteger && input == ( int ) input ) { return "" + ( int ) input ; } else { return "" + input ; } }
converts the input to a string with special missing value handling and integers represented as integers if possible .
