<%@ page contentType="text/html;charset=gb2312"%>
<%@ page import="java.text.*"%>
<%@ page import="java.util.*"%>
<%
//字符串转化成时间类型（字符串可以是任意类型，只要和SimpleDateFormat中的格式一致即可）
java.text.SimpleDateFormat sdf = new java.text.SimpleDateFormat("M/dd/yyyy hh:mm:ss a",java.util.Locale.US);
java.util.Date d = sdf.parse("5/13/2003 10:31:37 AM");
out.println(d);
out.println("<br/>");
SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
String mDateTime1=formatter.format(d);
out.println(mDateTime1);
out.println("<br/>");
out.println(d.getTime());
out.println("<br/>");
//当前时间
Calendar cal = Calendar.getInstance();
// SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss G E D F w W a E F");
String mDateTime=formatter.format(cal.getTime());
out.println(mDateTime);
out.println("<br/>");
//1年前日期
java.util.Date myDate=new java.util.Date();
long myTime=(myDate.getTime()/1000)-60*60*24*365;
myDate.setTime(myTime*1000);
String mDate=formatter.format(myDate);
out.println(mDate);
out.println("<br/>");
//明天日期
myDate=new java.util.Date();
myTime=(myDate.getTime()/1000)+60*60*24;
myDate.setTime(myTime*1000);
mDate=formatter.format(myDate);
out.println(mDate);
out.println("<br/>");
//两个时间之间的天数
SimpleDateFormat myFormatter = new SimpleDateFormat("yyyy-MM-dd");
java.util.Date date= myFormatter.parse("2003-05-1");
java.util.Date mydate= myFormatter.parse("1899-12-30");
long day=(date.getTime()-mydate.getTime())/(24*60*60*1000);
out.println(day);
out.println("<br/>");
//加半小时
SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd hh:mm:ss");
java.util.Date date1 = format.parse("2002-02-28 23:16:00");
long Time=(date1.getTime()/1000)+60*30;
date1.setTime(Time*1000);
String mydate1=formatter.format(date1);
out.println(mydate1);
out.println("<br/>");
//年月周求日期
SimpleDateFormat formatter2 = new SimpleDateFormat("yyyy-MM F E");
java.util.Date date2= formatter2.parse("2003-05 5 星期五");
SimpleDateFormat formatter3 = new SimpleDateFormat("yyyy-MM-dd");
String mydate2=formatter3.format(date2);
out.println(mydate2);
out.println("<br/>");
//求是星期几
mydate= myFormatter.parse("2001-1-1");
SimpleDateFormat formatter4 = new SimpleDateFormat("E");
String mydate3=formatter4.format(mydate);
out.println(mydate3);
out.println("<br/>");
%>
===========================
另一种
import java.text.DateFormat;
import java.text.ParseException;
import java.util.Date;
class test
{
public static void main(String[] args) throws ParseException
{
DateFormat df=DateFormat.getDateInstance();
String str1="2002-3-4";
String str2="2002-7-12";
long l1=df.parse(str1).getTime();//把字符串转化为时间
long l2=df.parse(str2).getTime();
long l3=0;//时间间隔
if(l1>l2)//判断时间先后
{
l3=l1-l2;
}else
{
l3=l2-l1;
}
l3=l3/(60*60*24*1000);
System.out.println(str1+"与"+str2+"相隔"+l3+"天!");
}
}