Date、LocalDateTime以及String互相转换

String 转 localdatetime

String datetime =  "2018-01-13 21:27:30";
DateTimeFormatter dtf = 
			DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss");
LocalDateTime parse = LocalDateTime.parse(datetime, dtf);
System.out.println("String 转 localdatetime: " +parse);

localdatetime 转 String

LocalDateTime now = LocalDateTime.now();
DateTimeFormatter dateTimeFormatter = 
			DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss");
String format = dateTimeFormatter.format(now);
System.out.println("localdatetime 转 String: " +format);

date 转 String

Date date = new Date();
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
String format1 = sdf.format(date);
System.out.println("date 转 String : " + format1);

String 转 date

String string = "2020-10-24 21:59:06";
SimpleDateFormat sdf1 = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
Date parse1 = sdf1.parse(string);
System.out.println("String 转 date : "+parse1);

date 转 localdatetime

Date date1 = new Date();
Instant instant = date1.toInstant();
LocalDateTime localDateTime = 
		instant.atZone(ZoneId.systemDefault()).toLocalDateTime();
System.out.println("date 转 localdatetime : " +localDateTime);

localdatetime 转 date

LocalDateTime now1 = LocalDateTime.now();
ZonedDateTime zonedDateTime = now1.atZone(ZoneId.systemDefault());
Instant instant1 = zonedDateTime.toInstant();
Date from = Date.from(instant1);
System.out.println("localdatetime 转 date : "+from);

补充：Timestamp 转 LocalDateTime

        Timestamp time = Timestamp.from(Instant.now());
        LocalDateTime localDateTime2 = time.toLocalDateTime();

补充： LocalDateTime 转 Timestamp

Timestamp tim1e = Timestamp.valueOf(LocalDateTime.now());