public final class DesUtils {

    private static final String DES = "DES";

    private static final String KEY = "4YztMHI7PsT4rLZN";

    private DesUtils() {}

    private static byte[] encrypt(byte[] src, byte[] key) throws Exception {

        SecureRandom sr = new SecureRandom();

        DESKeySpec dks = new DESKeySpec(key);

        SecretKeyFactory keyFactory = SecretKeyFactory.getInstance(DES);

        SecretKey secretKey = keyFactory.generateSecret(dks);

        Cipher cipher = Cipher.getInstance(DES);

        cipher.init(Cipher.ENCRYPT_MODE, secretKey, sr);

        return cipher.doFinal(src);

    }

    private static byte[] decrypt(byte[] src, byte[] key) throws Exception {

        SecureRandom sr = new SecureRandom();

        DESKeySpec dks = new DESKeySpec(key);

        SecretKeyFactory keyFactory = SecretKeyFactory.getInstance(DES);

        SecretKey secretKey = keyFactory.generateSecret(dks);

        Cipher cipher = Cipher.getInstance(DES);

        cipher.init(Cipher.DECRYPT_MODE, secretKey, sr);

        return cipher.doFinal(src);

    }

    private static String byte2hex(byte[] b) {

        String hs = "";

        String temp = "";

        for (int n = 0; n < b.length; n++) {

            temp = (java.lang.Integer.toHexString(b[n] & 0XFF));

            if (temp.length() == 1)

                hs = hs + "0" + temp;

            else

                hs = hs + temp;

        }

        return hs.toUpperCase();

    }

    private static byte[] hex2byte(byte[] b) {

        if ((b.length % 2) != 0)

            throw new IllegalArgumentException("length not even");

        byte[] b2 = new byte[b.length / 2];

        for (int n = 0; n < b.length; n += 2) {

            String item = new String(b, n, 2);

            b2[n / 2] = (byte) Integer.parseInt(item, 16);

        }

        return b2;

    }

    private static String decode(String src, String key) {

        String decryptStr = "";

        try {

            byte[] decrypt = decrypt(hex2byte(src.getBytes()), key.getBytes());

            decryptStr = new String(decrypt);

        } catch (Exception e) {

            e.printStackTrace();

        }

        return decryptStr;

    }

    private static String encode(String src, String key){

        byte[] bytes = null;

        String encryptStr = "";

        try {

            bytes = encrypt(src.getBytes(), key.getBytes());

        } catch (Exception ex) {

            ex.printStackTrace();

        }

        if (bytes != null)

            encryptStr = byte2hex(bytes);

        return encryptStr;

    }

    /**

     * 解密

     */

    public static String decode(String src) {

        return decode(src, KEY);

    }

    /**

     * 加密

     */

    public static String encode(String src) {

        return encode(src, KEY);

    }

}

public static void main(String[] args) {

    String ss = "uu123@#$";

    String encodeSS = encode(ss);

    System.out.println(encodeSS);

    String decodeSS = decode(encodeSS);

    System.out.println(decodeSS);

}

result:

    6EA84873A948B299936006D75B7CA819

    uu123@#$