import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;public class MainActivity {/*public static void main(String[] args) {// TODO Auto-generated method stubint[] A = { 1,8,2,5,4,3,6 };int[] B = Insertion.sort(A);print(B);}static void print(int[] arr) {for(int i=0; i<arr.length; i++) {System.out.print(arr[i]+" ");}}*/public static void main(String[] args) throws Exception{/* Date date1 = new SimpleDateFormat("yyyy-MM-dd").parse("2015-04-24 12:14:57"); Date date2 = new SimpleDateFormat("yyyy-MM-dd").parse("2015-03-25 12:14:57");Calendar cal1=Calendar.getInstance();Calendar cal2=Calendar.getInstance();cal1.setTime(date1);cal2.setTime(date2);System.out.println(date1.compareTo(date2));System.out.println(cal1.compareTo(cal2));String now = new SimpleDateFormat("yyyy年MM月dd日").format(date1);System.out.println(now);*/SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");java.util.Date now = df.parse("2015-04-24 12:14:57");java.util.Date date=df.parse("2015-03-25 12:14:57");long l=now.getTime()-date.getTime();long day=l/(24*60*60*1000);long hour=(l/(60*60*1000)-day*24);long min=((l/(60*1000))-day*24*60-hour*60);long s=(l/1000-day*24*60*60-hour*60*60-min*60);System.out.println(""+day+"天"+hour+"小时"+min+"分"+s+"秒");}}

如何利用java得到当前的时间和前一天的时间博客分类： 常用资料
JavaRubyCC++C#
1.得到当前的时间
Ruby代码  收藏代码
Calendar   cal   =   Calendar.getInstance();
String time=formatter.format(cal.getTime());
String strEnd=time.substring(0, 16);// 2007-10-30 09:30  2.得到前一天的时间
Ruby代码  收藏代码
Calendar   c   =   Calendar.getInstance();
c.add(Calendar.DAY_OF_MONTH, -1);
SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
String mDateTime=formatter.format(c.getTime());
String strStart=mDateTime.substring(0, 16);//2007-10-29 09:30  3.得到前几天的时间
Ruby代码  收藏代码
Calendar   c   =   Calendar.getInstance();
c.add(Calendar.DAY_OF_MONTH, -5);//得到前5
SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
String mDateTime=formatter.format(c.getTime());
String strStart=mDateTime.substring(0, 16);//2007-10-24 09:30  4.得到当前时间的前几年的时间 Ruby代码  收藏代码
Calendar   c   =   Calendar.getInstance();   c.add(Calendar.YEAR, -5);//得到前5年  SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");  String mDateTime=formatter.format(c.getTime());  String strStart=mDateTime.substring(0, 16);//2002-10-24 09:30  

CalendarDate转化(1) Calendar转化Date
Calendar cal=Calendar.getInstance();
Date date=cal.getTime();(2) Date转化Calendar
Date date=new Date();
Calendar cal=Calendar.getInstance();
cal.setTime(date);