java8时间转换

private static final String FORMAT = "yyyy-MM-dd HH:mm:ss";

LocalDateTime localDateTime = LocalDateTime.ofInstant(Instant.ofEpochSecond(1000000000L), ZoneId.systemDefault());

DateTimeFormatter dateTimeFormatter = DateTimeFormatter.ofPattern(FORMAT);

String date = localDateTime.format(dateTimeFormatter);

System.err.println(date);