英文官方文档:http://www.joda.org/joda-time/userguide.html 简介 想必大家在平时的项目开发中经常要处理日期的问题,比如需要处理两个日期间隔的天数,使用JDK1.8以前自带的日期API处理相当的繁琐(JDK1.8的API已经重写了日期库,其实也是借鉴了Joda-Time),那么接下来介绍的这款日期库工具(Joda-Time)就非常强大了,使用Joda-Time可以轻松的处理各种复杂的时间相关问题。 特点 易于使用:使用Joda-Time可以非常容易的处理一些复杂的日期问题 易于扩展:Joda-Time支持多达8种日历系统 线程安全:Joda类具有不可变性,因此它们的实例无法被修改 提供最新的时区计算 互操作性:与JDK可互操作…
November 9, 2017
Java:获取当前日期 How to get current date time
In this tutorial, we will show you how to get the current date time from the classic Date and Calendar APIs, and also the new Java 8 date and time APIs – LocalDateTime and LocalDate
1. Code Snippets
For java.util.Date
, just create a new Date()
DateFormat dateFormat = new SimpleDateFormat("yyyy/MM/dd HH:mm:ss"); Date date = new Date(); System.out.println(dateFormat.format(date)); //2017/11/16 12:08:43
For java.util.Calendar
, uses Calendar.getInstance()
DateFormat dateFormat = new SimpleDateFormat("yyyy/MM/dd HH:mm:ss"); Calendar cal = Calendar.getInstance(); System.out.println(dateFormat.format(cal)); //2017/11/16 12:08:43
For java.time.LocalDateTime
, uses LocalDateTime.now()
DateTimeFormatter dtf = DateTimeFormatter.ofPattern("yyyy/MM/dd HH:mm:ss"); LocalDateTime now = LocalDateTime.now(); System.out.println(dtf.format(now)); //2017/11/16 12:08:43
For java.time.LocalDate
, uses LocalDate.now()
DateTimeFormatter dtf = DateTimeFormatter.ofPattern("yyyy/MM/dd"); LocalDate localDate = LocalDate.now(); System.out.println(dtf.format(localDate)); //2017/11/16
2. Full Example
Review a full Java example to show you how to get the current date, time and display in a predefined format.
GetCurrentDateTime.java
package com.ikeepstudying; 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)); } }
Output
2016/11/16 12:08:43
2016/11/16 12:08:43
2016/11/16 12:08:43
2016/11/16
References
- Date JavaDoc
- Calendar JavaDoc
- SimpleDateFormat JavaDoc
- LocalDateTime JavaDoc
- LocalDate JavaDoc
- DateTimeFormatter JavaDoc
本文:Java:获取当前日期 How to get current date time