LocalDate,LocalDateTime,Date,日期串相互转换
1. 获取当前时间 XXX.now()
- public void testCurrentDate() {
- LocalDate curLocalDate = LocalDate.now();
- System.out.println("地心侠士: "+curLocalDate.toString());
- LocalTime curLoacalTime = LocalTime.now();
- System.out.println("地心侠士: "+curLoacalTime.toString());
- LocalDateTime curLocalDateTime = LocalDateTime.now();
- System.out.println("地心侠士: "+curLocalDateTime.toString());
- Instant curInstant = Instant.now();
- System.out.println("地心侠士: "+ curInstant.toString());
- }
复制代码 输出结果- 地心侠士: 2026-02-04
- 地心侠士: 17:15:59.715639800
- 地心侠士: 2026-02-04T17:15:59.715639800
- 地心侠士: 2026-02-04T09:15:59.715639800Z
复制代码 说明:
- LocalDate,LocalTime,LocalDateTime都是当前时区对应日期或时间
- Instant获取到的是UTC+0 日期和时间
- Z 代表零时区(UTC+0) T 日期和时间的分割符
2. 时间戳转成LocalDateTime
- public void testTimestamp() {
- Long timeStamp = 1769577638767L;
- Instant instant = Instant.ofEpochMilli(timeStamp);
- System.out.println("地心侠士: " + instant.toString());
- LocalDateTime cvLocalDate = LocalDateTime.ofInstant(instant, ZoneId.systemDefault());
- System.out.println("地心侠士: " + cvLocalDate.toString());
- LocalDateTime localDateT1 = LocalDateTime.ofEpochSecond(timeStamp / 1000, 0, ZoneOffset.ofHours(8));
- System.out.println("地心侠士: " + localDateT1.toString());
- }
复制代码 输出结果- 地心侠士: 2026-01-28T05:20:38.767Z
- 地心侠士: 2026-01-28T13:20:38.767
- 地心侠士: 2026-01-28T13:20:38
复制代码 说明:
- 使用方法 LocalDateTime.ofInstant 或者 LocalDateTime.ofEpochSecond
- 使用 ofInstant ,毫秒时间戳可以直接使用
- 使用 ofEpochSecond ,毫秒时间戳需要除以1000
- ofInstant 使用 ZoneId.systemDefault() 获取当时区
- OfEpochSecond 使用 ZoneOffset.ofHours(8) 指定需要的时区
- ZoneId.systemDefault() 当前时区,等同的有 ZoneId.of("Asia/Shanghai") ZoneId.of("GMT+8") ZoneId.of("UTC+08:00") ZoneId.of("+08:00")
3. 时间串转换成LocalDateTime
- public void testDateStr() {
- DateTimeFormatter df = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss.SSS");
- String dateStr = "2026-01-28 18:20:38.767";
- LocalDateTime localDateTime = LocalDateTime.parse(dateStr, df);
- System.out.println("地心侠士: " + localDateTime.toString());
- LocalDateTime defaultParse = LocalDateTime.parse("2026-01-28T18:20:38");
- System.out.println("地心侠士: " + defaultParse.toString());
- DateTimeFormatterBuilder dfBuild = new DateTimeFormatterBuilder();
- DateTimeFormatter dynmicDf = dfBuild.appendPattern("yyyy-MM-dd")
- .optionalStart()
- .appendLiteral(' ')
- .optionalEnd()
- .optionalStart()
- .appendLiteral('T')
- .optionalEnd()
- .appendPattern("HH:mm:ss")
- .toFormatter();
- LocalDateTime dynamic1 = LocalDateTime.parse("2026-01-28T18:20:38", dynmicDf);
- System.out.println("地心侠士: " + dynamic1.toString());
- LocalDateTime dynamc2 = LocalDateTime.parse("2026-01-28 18:20:38", dynmicDf);
- System.out.println("地心侠士: " + dynamc2.toString());
- }
复制代码 输出结果:- 地心侠士: 2026-01-28T18:20:38.767
- 地心侠士: 2026-01-28T18:20:38
- 地心侠士: 2026-01-28T18:20:38
- 地心侠士: 2026-01-28T18:20:38
复制代码 说明:
- 使用方法LocalDateTime.parse结合DateTimeFormatter转换
- 默认转换格式为yyyy-MM-ddTHH:mm:ss
- 使用 DateTimeFormatterBuilder 可以实现多种日期串转换成LocalDateTime
4. LocalDateTime转换成成LocalDate和Date
- public void testDateConvert() {
- LocalDateTime dt = LocalDateTime.now();
- System.out.println("地心侠士 " + dt.toString());
- System.out.println("LocalDateTime=>LocalDate");
- LocalDate localDate = dt.toLocalDate();
- System.out.println("地心侠士 " + localDate.toString());
- System.out.println("LocalDateTime=>Date");
- Instant instant = dt.toInstant(ZoneOffset.ofHours(8));
- Date d = Date.from(instant);
- System.out.println("地心侠士 " + d);
- }
复制代码 输出结果:- 地心侠士 2026-02-06T19:09:35.092605300
- LocalDateTime=>LocalDate
- 地心侠士 2026-02-06
- LocalDateTime=>Date
- 地心侠士 Fri Feb 06 19:09:35 CST 2026
复制代码 5. Date 转换成LocalDateTime
- public void testDateConvert2() {
- Date date = new Date();
- System.out.println("地心侠士 " + date.toString());
- System.out.println("Date=>LocalDateTime");
- Instant instant = date.toInstant();
- LocalDateTime lcd = LocalDateTime.ofInstant(instant, ZoneId.systemDefault());
- System.out.println("地心侠士 " + lcd.toString());
- }
复制代码 输出结果:- 地心侠士 Fri Feb 06 19:15:38 CST 2026
- Date=>LocalDateTime
- 地心侠士 2026-02-06T19:15:38.122
复制代码 6. 北京时间时区表示
- public void testZone() {
- ZoneId zonidGMT8 = ZoneId.of("GMT+8");
- LocalDateTime gmt8 = LocalDateTime.ofInstant(Instant.now(), zonidGMT8);
- System.out.println("地心侠士: " + gmt8.toString());
- ZoneId zonidAS = ZoneId.of("Asia/Shanghai");
- LocalDateTime as = LocalDateTime.ofInstant(Instant.now(), zonidAS);
- System.out.println("地心侠士: " + as.toString());
- ZoneId zonidUTC8 = ZoneId.of("UTC+08:00");
- LocalDateTime utc = LocalDateTime.ofInstant(Instant.now(), zonidUTC8);
- System.out.println("地心侠士: " + utc.toString());
- ZoneId zonid8 = ZoneId.of("+08:00");
- LocalDateTime ad8= LocalDateTime.ofInstant(Instant.now(), zonid8);
- System.out.println("地心侠士: " + ad8.toString());
- }
复制代码 输出结果:- 地心侠士: 2026-02-06T18:35:26.921795200
- 地心侠士: 2026-02-06T18:35:26.928776600
- 地心侠士: 2026-02-06T18:35:26.928776600
- 地心侠士: 2026-02-06T18:35:26.928776600
复制代码 原文地址:https://mp.weixin.qq.com/s/vH0TJKl89CfV3ehvHllgNg
来源:程序园用户自行投稿发布,如果侵权,请联系站长删除
免责声明:如果侵犯了您的权益,请联系站长,我们会及时删除侵权内容,谢谢合作! |