날짜 문자열 변환 주의사항 및 실례 (고전)

이전에 이 문제에 자주 부딪혔는데, 임시로 비고를 써서 이미 테스트하였다.

/**
	 *            	date   format             ，
	 *    ：getDateString("20180323143557882","yyyyMMddHHmmss")  getDateString("2018-03-23143557882","yyyy-MM-ddHHmmss");     getDateString("20180323143557882","yyyyMMdd_HHmmss");        
	 * @param date	           ：20180323143557882
	 * @param format			   yyyyMMddHHmmss
	 * @return
	 * @author huyanbin
	 */
	public static Date getDateString(String date, String format) {
		try {
			if (format == null)
				format = "yyyy-MM-dd HH:mm:ss";
			SimpleDateFormat sdf = new SimpleDateFormat(format);
			System.out.println(sdf.parse(date));
			return sdf.parse(date);
		} catch (Exception e) {
			return null;
		}

	}

	/**
	 *           
	 * @param date		Sat Mar 24 06:39:42 CST 2018
	 * @param format	yyyy-MM-dd HH:mm:ss
	 * @return
	 * @author huyanbin
	 */
	public static String dateFormatConversion(Date date, String format) {
		try {
			if (format == null)
				format = "yyyy-MM-dd HH:mm:ss";
			SimpleDateFormat sdf = new SimpleDateFormat(format);
			System.out.println(sdf.format(date));  
			return sdf.format(date);
		} catch (Exception e) {
			return null;
		}

	}

public static void main(String[] args) {
		dateFormatConversion(getDateString("20180323143557882","yyyyMMddHHmmss"),"yyyyMMdd_HHmmss");
	}