小墨の博客

1、获取时间前几天或者后几天

Calendar now=Calendar.getInstance();
now.add(Calendar.DATE,10);

2、Calendar时间戳转换

Calendar now=Calendar.getInstance();
System.out.println(now.getTimeInMillis());
Calendar now=Calendar.getInstance();
now.setTimeInMillis(1559188481978L);

3、Calendar格式化时间

SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
Calendar now = Calendar.getInstance();
System.out.println(df.format(now.getTime()));

4、String 转化Calendar

String str="2019-1-1";
SimpleDateFormat sdf= new SimpleDateFormat("yyyy-MM-dd");
Date date =sdf.parse(str);
Calendar calendar = Calendar.getInstance();
calendar.setTime(date);

5、String 转化Date

String str="2019-1-1";
SimpleDateFormat sdf= new SimpleDateFormat("yyyy-MM-dd");
Date date =sdf.parse(str);

6、Timestamp转String

SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
Timestamp ts = new Timestamp(System.currentTimeMillis());
String xxx=sdf.format(ts);

7、String转Timestamp

Timestamp ts = Timestamp.valueOf("2019-01-01 12:00:00");

8、Timestamp转LocalDateTime

Timestamp ts=Timestamp.from(Instant.now());
LocalDateTime ldt=ts.toLocalDateTime();

9、LocalDateTime转Timestamp

LocalDateTime ldt = LocalDateTime.now();
Timestamp ts = Timestamp.valueOf(ldt);

10、LocalDateTime转String

DateTimeFormatter df = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss");
LocalDateTime time = LocalDateTime.now();
String localTime = df.format(time);

11、String转LocalDateTime

DateTimeFormatter df = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss");
LocalDateTime ldt = LocalDateTime.parse("2019-08-23 12:00:00", df);

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