Java 时间相关总结

LocalDate与String互转

LocalDate转String

DateTimeFormatter df = DateTimeFormatter.ofPattern("yyyy-MM-dd");
LocalDate formatDate = LocalDate.of(2020, 2, 5);
String dateStr = formatDate.format(df);
System.out.println("LocalDate => String: " + dateStr);

String转LocalDate

DateTimeFormatter df = DateTimeFormatter.ofPattern("yyyy-MM-dd");
LocalDate dateParam = LocalDate.parse(dateStr, df);
System.out.println("String => LocalDate: " + dateParam);

LocalDate,LocalDateTime,LocalTime,Date转化

// 01. java.util.Date –> java.time.LocalDateTime

public void UDateToLocalDateTime() {

java.util.Date date = new java.util.Date();

Instant instant = date.toInstant();

ZoneId zone = ZoneId.systemDefault();

LocalDateTime localDateTime = LocalDateTime.ofInstant(instant, zone);

}

// 02. java.util.Date –> java.time.LocalDate

public void UDateToLocalDate() {

java.util.Date date = new java.util.Date();

Instant instant = date.toInstant();

ZoneId zone = ZoneId.systemDefault();

LocalDateTime localDateTime = LocalDateTime.ofInstant(instant, zone);

LocalDate localDate = localDateTime.toLocalDate();

}

// 03. java.util.Date –> java.time.LocalTime

public void UDateToLocalTime() {

java.util.Date date = new java.util.Date();

Instant instant = date.toInstant();

ZoneId zone = ZoneId.systemDefault();

LocalDateTime localDateTime = LocalDateTime.ofInstant(instant, zone);

LocalTime localTime = localDateTime.toLocalTime();

}

// 04. java.time.LocalDateTime –> java.util.Date

public void LocalDateTimeToUdate() {

LocalDateTime localDateTime = LocalDateTime.now();

ZoneId zone = ZoneId.systemDefault();

Instant instant = localDateTime.atZone(zone).toInstant();

java.util.Date date = Date.from(instant);

}

// 05. java.time.LocalDate –> java.util.Date

public void LocalDateToUdate() {

LocalDate localDate = LocalDate.now();

ZoneId zone = ZoneId.systemDefault();

Instant instant = localDate.atStartOfDay().atZone(zone).toInstant();

java.util.Date date = Date.from(instant);

}

// 06. java.time.LocalTime –> java.util.Date

public void LocalTimeToUdate() {

LocalTime localTime = LocalTime.now();

LocalDate localDate = LocalDate.now();

LocalDateTime localDateTime = LocalDateTime.of(localDate, localTime);

ZoneId zone = ZoneId.systemDefault();

Instant instant = localDateTime.atZone(zone).toInstant();

java.util.Date date = Date.from(instant);

}

int  转 date:

longnowTimeLong=newLong(nowTimeInt).longValue()*1000;

DateFormat Format=newSimpleDateFormat(“yyyy-MM-dd HH:mm:ss”);

String nowTimeStr=Format.format(nowTimeLong);

Date nowTimeDate=Format.parse(nowTimeStr);