Java LocalDateTime 和 Date 互转
1 LocalDateTime -> Date
2 Date -> LocalDateTime
3 str -> LocalDateTime
4 LocalDateTime -> str
1 LocalDateTime -> Date
@Test
public void test() {
    // DateTimeFormatter / SimpleDateFormat
    DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss");
    SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");

    // LocalDateTime -> Date
    LocalDateTime time1 = LocalDateTime.now();
    Date date = Date.from(time1.atZone(ZoneId.systemDefault()).toInstant());
    
    // Print
    System.out.println(format.format(date));
}

2022-04-13 16:01:42

2 Date -> LocalDateTime
@Test
public void test() {
    // DateTimeFormatter / SimpleDateFormat
    DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss");
    SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");

    // Date -> LocalDateTime
    LocalDateTime time2 = new Date().toInstant().atZone(ZoneId.systemDefault()).toLocalDateTime();

    // Print
    System.out.println(formatter.format(time2));
}

2022-04-13 16:01:42

3 str -> LocalDateTime
@Test
public void test() {
    // DateTimeFormatter
    DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss", Locale.US);

    // str -> LocalDateTime
    LocalDateTime time2 = LocalDateTime.parse("2022-04-13 16:01:42", formatter);

    // Print
    System.out.println(formatter.format(time2));
}

2022-04-13 16:01:42

4 LocalDateTime -> str
@Test
public void test() {
    // DateTimeFormatter
    DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss", Locale.US);

    // LocalDateTime
    LocalDateTime time2 = LocalDateTime.now();

    // Print
    System.out.println(formatter.format(time2));
}

2022-04-13 16:01:42