日期格式转化

时间格式转化和转为英文， 以及日期序数化。

public class DateParse {
	@SuppressWarnings("unused")
	//根据教师类型存储英文日期
	public static String ParseDate(String time, String teacherType)
			throws ParseException {

		if (null == time && "" == time) {
			return "";
		}
		Locale l = new Locale("en");
		SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
		Date date = sdf.parse(time);
		String day = String.format("%td", date);
		String month = String.format(l, "%tB", date);
		String year = String.format("%tY", date);
		day = getOrdinal(day);
		//5001 特邀 5002 特聘
		/*if (teacherType == "5001") {
			return month + " " + day + "," + year;*/
		/*} else {*/
			return month + " ," + year;
		/*}*/
	}

	//日期转化为序数词
	public static String getOrdinal(String day) {

		int dayNum = Integer.parseInt(day);
		String tail = null;
		if (1 == dayNum) {
			return "1st";
		} else if (2 == dayNum) {
			return "2nd";
		} else if (3 == dayNum) {
			return "3rd";
		} else if (dayNum >= 20) {
			int last = dayNum % 10;
			if (1 == last) {
				tail = "st";
			} else if (2 == last) {
				tail = "nd";
			} else if (3 == last) {
				tail = "rd";
			} else {
				tail = "th";
			}
		} else {
			tail = "th";
		}
		return dayNum + tail;
	}

	//日期转化，去0
	public static String DateChange(String time) throws ParseException {
		SimpleDateFormat sdf = new SimpleDateFormat("yyyy-M-d");
		Date date = sdf.parse(time);

		String resultTime = sdf.format(date);

		return resultTime;

	}
	//讲师聘用开始结束时间格式存入
	public static String DateChangeEn(String time) throws ParseException {
		SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
		Date date = sdf.parse(time);

		String resultTime = sdf.format(date);

		return resultTime;

	}

}