java日期相减

import java.text.ParseException;
import java.text.SimpleDateFormat;


public class JavaTest {

	/**
	 * @param args
	 * @throws ParseException 
	 */
	public static void main(String[] args) throws ParseException {
		// TODO Auto-generated method stub
		  SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
		   java.util.Date now = df.parse("2004-03-26 13:31:34");
		   java.util.Date date=df.parse("2004-01-02 11:30:53");
		   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");

	}

}