private static boolean valueFieldIsCharArray(){
  Object o=UNSAFE.getObject("",STRING_VALUE_FIELD_OFFSET);
  return (o instanceof char[]);
}

private static boolean valueFieldIsCharArray ( ) { Object o = UNSAFE . getObject ( "" , STRING_VALUE_FIELD_OFFSET ) ; return ( o instanceof char [ ] ) ; }
jdk9 compat strings enhancement changed the internal representation of the value field from a char [ ] to a byte [ ] ( see http : / / openjdk . java . net / jeps / 254 ) .
