java实现日期和时间
时间: 2023-11-14 21:08:31 浏览: 47
Java中可以使用java.util.Date和java.util.Calendar类来实现日期和时间的处理。下面是一些示例代码:
获取当前日期和时间:
```
Date now = new Date();
System.out.println(now);
```
格式化日期:
```
SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd");
String formattedDate = formatter.format(now);
System.out.println(formattedDate);
```
获取指定日期的年、月、日:
```
Calendar cal = Calendar.getInstance();
cal.setTime(now);
int year = cal.get(Calendar.YEAR);
int month = cal.get(Calendar.MONTH) + 1;
int day = cal.get(Calendar.DAY_OF_MONTH);
System.out.println(year + "-" + month + "-" + day);
```
计算两个日期之间的天数:
```
Date date1 = formatter.parse("2021-01-01");
Date date2 = formatter.parse("2021-01-10");
long diff = date2.getTime() - date1.getTime();
long days = TimeUnit.DAYS.convert(diff, TimeUnit.MILLISECONDS);
System.out.println(days);
```