nanoOfSecond为0时: LocalDateTime localDateTime = LocalDateTime.of(2018, 8, 31, 15, 26, 37, 0); JSON.toJSONString(localDateTime);//2018-08-31 15:26:37 localDateTime.toString();//2018-08-31T15:26:37
nanoOfSecond不为0时: LocalDateTime localDateTime = LocalDateTime.of(2018, 8, 31, 15, 26, 37, 1); JSON.toJSONString(localDateTime).toString();//2018-08-31T15:26:37.000000001 localDateTime.toString();//2018-08-31T15:26:37.000000001