时间操作

介绍

[TOC]

java 获取当天（今日）零点零分零秒

1.日期格式的

Calendar calendar = Calendar.getInstance();
calendar.setTime(new Date());
calendar.set(Calendar.HOUR_OF_DAY, 0);
calendar.set(Calendar.MINUTE, 0);
calendar.set(Calendar.SECOND, 0);
Date zero = calendar.getTime();

2.时间戳

long current = System.currentTimeMillis();
long zero = current/(1000*3600*24)*(1000*3600*24) - TimeZone.getDefault().getRawOffset();

获取当前或者未来时间

public class TimeClass {  
  
    public static void main(String[] args) {  
  
        // 获取一个小时以后的时间  
        Calendar calendar = Calendar.getInstance();  
        SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");  
        calendar.set(Calendar.HOUR_OF_DAY,  
                calendar.get(Calendar.HOUR_OF_DAY) + 1);  
  
        System.out.println("当前的时间：" + df.format(new Date()));  
        System.out.println("一个小时前的时间：" + df.format(calendar.getTime()));  
        // 获取一秒以后  
        calendar = Calendar.getInstance();  
        calendar.set(Calendar.SECOND,  
                calendar.get(Calendar.SECOND) + 1);  
        df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");  
        System.out.println("一秒以后的时间：" + df.format(calendar.getTime()));  
  
        // 获取一天以后的时间  
        calendar = Calendar.getInstance();  
        calendar.set(Calendar.DAY_OF_YEAR,  
                calendar.get(Calendar.DAY_OF_YEAR) + 1);  
        df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");  
        System.out.println("一天以后的时间：" + df.format(calendar.getTime()));  
  
        // 获取一个星期以后的时间  
        calendar = Calendar.getInstance();  
        calendar.set(Calendar.WEEK_OF_YEAR,  
                calendar.get(Calendar.WEEK_OF_YEAR) + 1);  
        df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");  
        System.out.println("一个星期以后的时间：" + df.format(calendar.getTime()));  
  
        // 获取一个月以后的时间  
        calendar = Calendar.getInstance();  
        calendar.add(Calendar.MONTH, 1);  
        df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");  
        System.out.println("一个月以后的时间：" + df.format(calendar.getTime()));  
  
    }  
  
}