MD5

简易版

private static String convertMD5(String key){
		MessageDigest md;
		try {
			md = MessageDigest.getInstance("MD5");
			md.update((key+partnerId).getBytes());
			String md5Check = new BigInteger(1, md.digest()).toString(16);
			return md5Check;
		}catch(Exception e){
			logger.error(e.getMessage(), e);
			return "";
		}
	}

TB版

	private static String convertMD5(String key){
		key = key+partnerId;
        MessageDigest md5 = null;
        try{
            md5 = MessageDigest.getInstance("MD5");
        }catch (Exception e){
        	logger.error(" md5 validate error: " + key, e);
        	return "";
        }
        char[] charArray = key.toCharArray();
        byte[] byteArray = new byte[charArray.length];

        for (int i = 0; i < charArray.length; i++)
            byteArray[i] = (byte) charArray[i];
        byte[] md5Bytes = md5.digest(byteArray);
        StringBuffer hexValue = new StringBuffer();
        for (int i = 0; i < md5Bytes.length; i++){
            int val = ((int) md5Bytes[i]) & 0xff;
            if (val < 16)
                hexValue.append("0");
            hexValue.append(Integer.toHexString(val));
        }
        return hexValue.toString();
	}

JJE版

public class MD5Utils {

	private final static String[] hexDigits = { "0", "1", "2", "3", "4", "5",
			"6", "7", "8", "9", "a", "b", "c", "d", "e", "f" };

	public static String generatePassword(String inputString) {
		return encodeByMD5(inputString);
	}
	
	public static String generateHexString(byte[] inputByte) {
		return encodeByMD5(inputByte);
	} 
	
	private static String encodeByMD5(byte[] originByte) {
		if (originByte != null) {
			try {
				MessageDigest md = MessageDigest.getInstance("MD5");
				byte[] results = md.digest(originByte);
				String resultString = byteArrayToHexString(results);
				String pass = resultString.toUpperCase();
				return pass;
			} catch (Exception ex) {
				ex.printStackTrace();
			}
		}
		return null;
	}

	private static String encodeByMD5(String originString) {
		if (originString != null) {
			try {
				MessageDigest md = MessageDigest.getInstance("MD5");
				byte[] results = md.digest(originString.getBytes());
				String resultString = byteArrayToHexString(results);
				String pass = resultString.toUpperCase();
				return pass;
			} catch (Exception ex) {
				ex.printStackTrace();//TODO change to use logger?
			}
		}
		return null;
	}

	
	private static String byteArrayToHexString(byte[] b) {
		StringBuffer resultSb = new StringBuffer();
		for (int i = 0; i < b.length; i++) {
			resultSb.append(byteToHexString(b[i]));
		}
		return resultSb.toString();
	}

	private static String byteToHexString(byte b) {
		int n = b;
		if (n < 0)
			n = 256 + n;
		int d1 = n / 16;
		int d2 = n % 16;
		return hexDigits[d1] + hexDigits[d2];
	}

    public static void main(String[] args){
        System.out.println(generatePassword("182529217120001034991800"));
    }
}