Android：DES加密

    private static final String KEY = "xxxxxx"; // KEY的字节长度必须超过24
    
    public DESUtil(){
        super();
    }
    
    /** DES加密  
     * @param str 要加密的内容
     */
    public String getDES(String str){
        if(TextUtils.isEmpty(str)){
            return null;
        }
        
        try {
            byte[] data = str.getBytes("UTF-8");
            byte[] key = KEY.getBytes();
            LogUtil.info("json", "length= " + key.length);
            
            return Base64.encodeToString(des3EncodeECB(key,data), Base64.DEFAULT);
        } catch (Exception e) {
            // TODO: handle exception
            e.printStackTrace();
        }
        
        return null;
    }

    /**
     * ECB加密,不要IV
     * @param key 密钥
     * @param data 明文
     * @return Base64编码的密文
     * @throws Exception
     */
    private byte[] des3EncodeECB(byte[] key, byte[] data)
            throws Exception {

        Key deskey = null;
        DESedeKeySpec spec = new DESedeKeySpec(key);
        SecretKeyFactory keyfactory = SecretKeyFactory.getInstance("desede");
        deskey = keyfactory.generateSecret(spec);

        Cipher cipher = Cipher.getInstance("desede" + "/ECB/PKCS5Padding");

        cipher.init(Cipher.ENCRYPT_MODE, deskey);
        byte[] bOut = cipher.doFinal(data);

        return bOut;
    }

    /**
     * ECB解密,不要IV
     * @param key 密钥
     * @param data Base64编码的密文
     * @return 明文
     * @throws Exception
     */
    private byte[] ees3DecodeECB(byte[] key, byte[] data)
            throws Exception {

        Key deskey = null;
        DESedeKeySpec spec = new DESedeKeySpec(key);
        SecretKeyFactory keyfactory = SecretKeyFactory.getInstance("desede");
        deskey = keyfactory.generateSecret(spec);

        Cipher cipher = Cipher.getInstance("desede" + "/ECB/PKCS5Padding");

        cipher.init(Cipher.DECRYPT_MODE, deskey);

        byte[] bOut = cipher.doFinal(data);

        return bOut;

    }

    /**
     * CBC加密
     * @param key 密钥
     * @param keyiv IV
     * @param data 明文
     * @return Base64编码的密文
     * @throws Exception
     */
    private byte[] des3EncodeCBC(byte[] key, byte[] keyiv, byte[] data)
            throws Exception {

        Key deskey = null;
        DESedeKeySpec spec = new DESedeKeySpec(key);
        SecretKeyFactory keyfactory = SecretKeyFactory.getInstance("desede");
        deskey = keyfactory.generateSecret(spec);

        Cipher cipher = Cipher.getInstance("desede" + "/CBC/PKCS5Padding");
        IvParameterSpec ips = new IvParameterSpec(keyiv);
        cipher.init(Cipher.ENCRYPT_MODE, deskey, ips);
        byte[] bOut = cipher.doFinal(data);

        return bOut;
    }

    /**
     * CBC解密
     * @param key 密钥
     * @param keyiv IV
     * @param data Base64编码的密文
     * @return 明文
     * @throws Exception
     */
    private byte[] des3DecodeCBC(byte[] key, byte[] keyiv, byte[] data)
            throws Exception {

        Key deskey = null;
        DESedeKeySpec spec = new DESedeKeySpec(key);
        SecretKeyFactory keyfactory = SecretKeyFactory.getInstance("desede");
        deskey = keyfactory.generateSecret(spec);

        Cipher cipher = Cipher.getInstance("desede" + "/CBC/PKCS5Padding");
        IvParameterSpec ips = new IvParameterSpec(keyiv);

        cipher.init(Cipher.DECRYPT_MODE, deskey, ips);

        byte[] bOut = cipher.doFinal(data);

        return bOut;

    }