Java计算天数差

import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;

public class Test_1 {
	public static void main(String[] args) {
		SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
		Date d1;
		try {
			d1 = sdf.parse("2012-09-08 10:10:10");
			Date d2 = sdf.parse("2012-09-15 00:00:00");
			System.out.println(daysBetween(d1, d2));

			System.out.println(daysBetween("2012-09-08 10:10:10",
					"2012-09-15 00:00:00"));
		} catch (ParseException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}

	}

	/**
	 * 计算两个日期之间相差的天数
	 * 
	 * @param smdate
	 *            较小的时间
	 * @param bdate
	 *            较大的时间
	 * @return 相差天数
	 * @throws ParseException
	 */
	publi