Java 方便调用的工具类

//时间格式化 （string型转date型 date转string）
//String pattern 如：yyyy-MM-dd hh:mm:ss
private static Map<String, DateFormat> dateFormatMap = new HashMap<String, DateFormat>();
public synchronized static String date2Str(Date date, String pattern) {
		String result = null;
		DateFormat df = null;
		if (dateFormatMap.containsKey(pattern)) {
			df = dateFormatMap.get(pattern);
		} else {
			df = new SimpleDateFormat(pattern);
			dateFormatMap.put(pattern, df);
		}

		try {
			result = df.format(date);
		} catch (Exception e) {
			e.printStackTrace();
		}

		return result;
	}

	public synchronized static Date str2Date(String dateStr, String pattern) {
		Date date = null;
		DateFormat df = null;
		if (dateFormatMap.containsKey(pattern)) {
			df = dateFormatMap.get(pattern);
		} else {
			df = new SimpleDateFormat(pattern);
			dateFormatMap.put(pattern, df);
		}
		try {
			date = df.parse(dateStr);
		} catch (Exception e) {
		}

		return date;
	}
/**
	 * 获取登录IP
	 * */
	public static String getLocalIp(){
		String ip=null;
		try {
			ip= InetAddress.getLocalHost().toString();
		} catch (UnknownHostException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		
		return ip;
	}
       

/**
	 * 分转化为元
	 * 
	 * @param fen
	 */
	public static float fen2Yuan(long fen) {

		BigDecimal bg = new BigDecimal(Long.toString(fen));
		BigDecimal rate = new BigDecimal("0.01");
		return bg.multiply(rate).floatValue();
	}



	/**
	 * 
	 * 将字符串的变成以分为计量单位的long型数字
	 * 
	 * @param number
	 * @return
	 */
	public static long getMoneyByFen(String number, boolean calculateByYuan)
			throws NumberFormatException {
		if (isNullOrEmpty(number)) {
			throw new NumberFormatException();
		}

		long result = 0;
		// 0.21,1.23
		if (number.indexOf(".") != -1) {

			if (!isFloat(number)) {
				throw new NumberFormatException();
			}

			Float floatNumber = Float.parseFloat(number);
			BigDecimal bd = new BigDecimal(Float.toString(floatNumber));
			result = (bd.multiply(new BigDecimal("100"))).longValue();
		} else {
			if (!isLongNumber(number)) {
				throw new NumberFormatException();
			} else if (calculateByYuan) {
				BigDecimal bd = new BigDecimal(number);
				result = (bd.multiply(new BigDecimal("100"))).longValue();
			} else {
				result = Long.parseLong(number);
			}
		}

		return result;
	}

public static Date getLocalDateTime() {
		java.util.Calendar c = java.util.Calendar.getInstance();
		java.text.SimpleDateFormat f = new java.text.SimpleDateFormat(
				"yyyy-MM-dd HH:mm:ss");
		Date date = Tool.str2Date(f.format(c.getTime()),
				Constant.DATE_PATTERN_BASE);
		return date;
	}