Java各种常用时间转换

java中经常会用到的时间转换方法，在此记录，拿来即用

以下代码如无特殊说明format格式为一下几种中的一种，转换格式具体自己定义

public static final String DEFAULT_DATE_FORMAT = "yyyy-MM-dd";
public static final String DATE_FORMAT_YYYYMMDD = "yyyyMMdd";
public static final String DEFAULT_DATETIME_FORMAT = "yyyy-MM-dd HH:mm:ss";
public static final String DEFAULT_DATETIME_FORMAT2 = "yyyy年MM月dd日  HH:mm:ss";

/**
	 * 获取时间戳
	 * 
	 * @return
	 */
	public static long getTimeStamp() {
		long tiemstamp = System.currentTimeMillis();
		return tiemstamp;

	}

/**
	 * 获取当前日期 字符串
	 * @param DATEFORMAT
	 * 日期格式字符串 如： yyyy-MM-dd
	 * @return
	 */
	public static String getNowDateStr(String DATEFORMAT) {
		Date date = new Date();
		SimpleDateFormat formatter = new SimpleDateFormat(DATEFORMAT);
		String nowdate = formatter.format(date);
		return nowdate;
	}

/**
	 * HH:mm 格式时间 转换为 HHmm格式
	 * 
	 * @param timeStr
	 * @return
	 */
	public static String switchTime(String timeStr) {
		String time = "";
		if (timeStr != null && timeStr.length() > 4) {
			String hour = timeStr.substring(0, 2);
			String minutes = timeStr.substring(3, 5);
			time = hour + minutes;
		}
		return time;
	}

/**
	 * 字符串转时间Str to Date
	 * 
	 * @param dstr
	 * @return
	 */
	public static Date StringToDate(String dstr, String DATEFORMAT) {
		Date mdate = new Date();
		SimpleDateFormat sd = new SimpleDateFormat(DATEFORMAT);// MM-dd
		try {
			mdate = sd.parse(dstr);
		} catch (ParseException e) {
			System.out.println("输入的日期格式有误！");
		}
		return mdate;
	}

/**
	 * 
	 * @param datestr
	 *            时间字符串
	 * @param mm
	 *            分钟数
	 * @param DATEFORMAT
	 *            格式
	 * @return  mm分钟前的时间 Str
	 */
	public static String getDate_Desmm(String datestr, int mm, String DATEFORMAT) {
		SimpleDateFormat formatter = new SimpleDateFormat(DATEFORMAT);
		Date curDate = StringToDate(datestr, DATEFORMAT);
		Date date = new Date(curDate.getTime() - mm * 60 * 1000);

		Calendar calendar = Calendar.getInstance();
		calendar.setTime(date);
		String mdate = formatter.format(date);
		return mdate;
	}

/**
	 * 
	 * @param datestr
	 *            时间字符串
	 * @param mm
	 *            分钟数
	 * @param DATEFORMAT
	 *            格式
	 * @return	mm分钟后的时间 Str
	 */
	public static String getDate_Addmm(String datestr, int mm, String DATEFORMAT) {
		SimpleDateFormat formatter = new SimpleDateFormat(DATEFORMAT);
		Date curDate = StringToDate(datestr, DATEFORMAT);
		Date date = new Date(curDate.getTime() + mm * 60 * 1000);

		Calendar calendar = Calendar.getInstance();
		calendar.setTime(date);
		String mdate = formatter.format(date);
		return mdate;
	}

/**
	 * 时间戳转时间字符串
	 * 
	 * @param timestampString
	 * @param DATEFORMAT
	 * @return
	 */
	public static String TimeStamp2DateStr(String timestampString,
			String DATEFORMAT) {
		Long timestamp = Long.parseLong(timestampString);
		String date = new java.text.SimpleDateFormat(DATEFORMAT)
				.format(new java.util.Date(timestamp));
		return date;
	}

/**
	 * 时间戳转日期
	 * 
	 * @param timestampString
	 * @param DATEFORMAT
	 * @return
	 */
	public static Date TimeStamp2Date(String timestampString, String DATEFORMAT) {
		Long timestamp = Long.parseLong(timestampString);
		Date date = new Date(timestamp);// 获取当前时间
		return date;
	}

/**
	 * 判断date1是否小于date2
	 * 
	 * @param date1
	 * @param date2
	 */
	public static boolean DateCompareSmall(Date date1, Date date2) {
		boolean result = date1.before(date2);
		return result;
	}

/**
	 * 判断date1是否大于date2
	 * 
	 * @param date1
	 * @param date2
	 */
	public static boolean DateCompareBig(Date date1, Date date2) {
		boolean result = date1.after(date2);
		return result;
	}