java代码计算2个时间差，精确到 天、月、日、时、分、秒、毫秒

/**
	 * 两个时间相差距离多少天多少小时多少分多少秒
	 * @param str1 时间参数 1 格式：2016-06-22 18:21:20
	 * @param str2 时间参数 2 格式：2016-06-22 17:21:20
	 * @param pattern 日期格式 yyyy-MM-dd HH:mm:ss    毫秒(yyyy-MM-dd HH:mm:ss.SSS)
	 * @return String 返回值为：xx天xx小时xx分xx秒
	 */
	public static String getDistanceTime(String str1, String str2, String pattern) {
		DateFormat df = new SimpleDateFormat(pattern);
		Date one;
		Date two;
		long day = 0;
		long hour = 0;
		long min = 0;
		long sec = 0;
		long ms = 0;
		try {
			one = df.parse(str1);
			two = df.parse(str2);
			long time1 = one.getTime();
			long time2 = two.getTime();
			long diff ;
			if(time1 < time2) {
				diff = time2 - time1;
			} else {
				diff = time1 - time2;
			}
			day = diff / (24 * 60 * 60 * 1000);
			hour = (diff / (60 * 60 * 1000) - day * 24);
			min = ((diff / (60 * 1000)) - day * 24 * 60 - hour * 60);
			sec = (diff/1000-day*24*60*60-hour*60*60-min*60);
			//ms = (diff - day * 24 * 60 * 60 * 1000 - hour * 60 * 60 * 1000 - min * 60 * 1000 - sec * 1000);
		} catch (ParseException e) {
			e.printStackTrace();
		}
		return day + "天" + hour + "小时" + min + "分" + sec + "秒";
		//return day + "天" + hour + "小时" + min + "分" + sec + "秒" + ms + "毫秒";
	}