在本文中,我将向您展示如何从经典的Date和Calendar API以及新的Java 8日期和时间API – LocalDateTime和LocalDate获取当前日期时间。
1.代码
对于java.util.Date
,只需创建一个新的Date()
DateFormat dateFormat = new SimpleDateFormat("yyyy/MM/dd HH:mm:ss");
Date date = new Date();
System.out.println(dateFormat.format(date)); //2020/05/16 12:08:43
对于java.util.Calendar
,使用Calendar.getInstance()
DateFormat dateFormat = new SimpleDateFormat("yyyy/MM/dd HH:mm:ss");
Calendar cal = Calendar.getInstance();
System.out.println(dateFormat.format(cal)); //2020/05/16 12:08:43
对于java.time.LocalDateTime
,使用LocalDateTime.now()
DateTimeFormatter dtf = DateTimeFormatter.ofPattern("yyyy/MM/dd HH:mm:ss");
LocalDateTime now = LocalDateTime.now();
System.out.println(dtf.format(now)); //2020/05/16 12:08:43
对于java.time.LocalDate
,使用LocalDate.now()
DateTimeFormatter dtf = DateTimeFormatter.ofPattern("yyyy/MM/dd");
LocalDate localDate = LocalDate.now();
System.out.println(dtf.format(localDate)); //2020/05/16
2.完整例子
查看完整的Java示例,向您展示如何获取当前日期,时间并以预定义的格式显示。
GetCurrentDateTime.java
package com.lintao;
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.time.LocalDateTime;
import java.time.format.DateTimeFormatter;
import java.util.Calendar;
import java.util.Date;
public class GetCurrentDateTime {
private static final DateFormat sdf = new SimpleDateFormat("yyyy/MM/dd HH:mm:ss");
private static final DateTimeFormatter dtf = DateTimeFormatter.ofPattern("yyyy/MM/dd HH:mm:ss");
public static void main(String[] args) {
Date date = new Date();
System.out.println(sdf.format(date));
Calendar cal = Calendar.getInstance();
System.out.println(sdf.format(cal.getTime()));
LocalDateTime now = LocalDateTime.now();
System.out.println(dtf.format(now));
LocalDate localDate = LocalDate.now();
System.out.println(DateTimeFormatter.ofPattern("yyy/MM/dd").format(localDate));
}
}
输出
2020/05/16 12:08:43
2020/05/16 12:08:43
2020/05/16 12:08:43
2020/05/16