日期時間處理
Java8內每個類含義
在 Java8 之前操作時間,用的都是 Date 和 Calendar 類,但這兩個類,操作起來及其繁瑣,且在時間轉換、時區轉換的時候也很麻煩,因此 JDK 官方在 8 之後,引入了 LocalDateTime 以及相關類,通過新的類來定義和操作時間,也十分的簡單清晰,下面我們就來我看一下如何操作。
- Instant: 時間戳
- Duration: 持續時間, 時間差
- LocalDate: 只包含⽇期, ⽐如: 2016-10-20
- LocalTime: 只包含時間, ⽐如: 231210
- LocalDateTime: 包含⽇期和時間, ⽐如: 2016-10-20 231421
- Period: 時間段
- ZoneOffset: 時區偏移量, ⽐如: +8:00
- ZonedDateTime: 帶時區的時間
- Clock: 時鐘, ⽐如獲取⽬前美國紐約的時間
代碼實現
localdatetime -> 其他類型
// =================================================================================
public static Date localDateTimeToDate(LocalDateTime localDateTime) {
Date date = Date.from(localDateTime.toInstant(ZoneOffset.ofHours(8)));
return date;
}
public static Date localDateTimeToDate(LocalDateTime localDateTime, ZoneOffset zoneOffset) {
Date date = Date.from(localDateTime.toInstant(zoneOffset));
return date;
}
public static long localDateTimeToTimestamp(LocalDateTime localDateTime) {
long timestamp = localDateTime.toInstant(ZoneOffset.ofHours(8)).getEpochSecond();
return timestamp;
}
public static long localDateTimeToTimestamp(LocalDateTime localDateTime, ZoneOffset zoneOffset) {
long timestamp = localDateTime.toInstant(zoneOffset).getEpochSecond();
return timestamp;
}
public static String localDateTimeToString(LocalDateTime localDateTime) {
DateTimeFormatter dateTimeFormatter = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss");
String string = dateTimeFormatter.format(localDateTime);
return string;
}
public static String localDateTimeToString(LocalDateTime localDateTime, DateTimeFormatter dateTimeFormatter) {
String string = dateTimeFormatter.format(localDateTime);
return string;
}
public static String localDateTimeToString(LocalDateTime localDateTime, String pattern) {
DateTimeFormatter dateTimeFormatter = DateTimeFormatter.ofPattern(pattern);
String string = dateTimeFormatter.format(localDateTime);
return string;
}
date -> 其他類型
// =================================================================================
public static long dateToTimeStamp(Date date) {
return date.getTime();
}
public synchronized static String dateToString(Date date, SimpleDateFormat simpleDateFormat) {
return simpleDateFormat.format(date);
}
public static String dateToString(Date date) {
SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
return simpleDateFormat.format(date);
}
public static LocalDateTime dateToLocalDateTime(Date date) {
LocalDateTime localDateTime = LocalDateTime.ofInstant(date.toInstant(), ZoneId.systemDefault());
return localDateTime;
}
public static LocalDateTime dateToLocalDateTime(Date date, ZoneId zoneId) {
LocalDateTime localDateTime = LocalDateTime.ofInstant(date.toInstant(), zoneId);
return localDateTime;
}
timestamp -> 其他類型
// =================================================================================
public static Date timestampToDate(long timestamp) {
return new Date(timestamp);
}
public static LocalDateTime timestampToLocalDateTime(long timestamp) {
LocalDateTime localDateTime = Instant.ofEpochSecond(timestamp).atZone(ZoneOffset.ofHours(8)).toLocalDateTime();
return localDateTime;
}
string -> 其他類型
// =================================================================================
public static Date stringToDate(String string, SimpleDateFormat simpleDateFormat) throws ParseException {
return simpleDateFormat.parse(string);
}
public static Date stringToDate(String string) throws ParseException {
SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
return simpleDateFormat.parse(string);
}
public static LocalDateTime stringToLocalDateTime(String string) {
DateTimeFormatter dateTimeFormatter = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss");
LocalDateTime localDateTime = LocalDateTime.parse(string, dateTimeFormatter);
return localDateTime;
}
public static LocalDateTime stringToLocalDateTime(String string, DateTimeFormatter dateTimeFormatter) {
LocalDateTime localDateTime = LocalDateTime.parse(string, dateTimeFormatter);
return localDateTime;
}
public static long stringToTimestamp(String string) {
DateTimeFormatter dateTimeFormatter = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss");
LocalDateTime localDateTime = LocalDateTime.parse(string, dateTimeFormatter);
long timestamp = localDateTime.toInstant(ZoneOffset.ofHours(8)).getEpochSecond();
return timestamp;
}
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