java 计算两个日期之间天数

 

import java.text.ParseException;import java.text.SimpleDateFormat;/** * @author JavaAlpha * @date 2011-8-23 * @version V 1.0 */public class TT {/** * @param args */public static void main(String[] args) {SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd");    long to = 0;try {to = df.parse("2011-4-15").getTime();} catch (ParseException e) {e.printStackTrace();}    long from = 0;try {from = df.parse("2011-8-20").getTime();} catch (ParseException e) {e.printStackTrace();}    System.out.println((from - to) / (1000 * 60 * 60 * 24));}}