Java實現AES算法

　　使用AES算法可用於對數據進行加密碼與解密，使用的時候需要注意兩點：1）被加密的串越長，加密后的字符串越長，注意數據庫字段的設計；2）Linux與Windows環境中可能會出現由於環境差異導致在Windows中測試成功，到Linux上后加密的串無法被正確解密。下列算法已在真實環境中進行實測，應用時也務必做好二次驗證避免出現線上事故。

    private static final String ALGORITHM_NAME = "AES";
　　 //加密因子，可根據您的需要自定義
    private static final String DEFAULT_ENCRYPT_RULE = "AES/CBC/PKCS5Padding";
    private static final String RANDOM_KEY_ALGORITHM = "SHA1PRNG";
    private static final String RANDOM_KEY_ALGORITHM_PROVIDER = "SUN";

    /**
     * AES加密
     * @param content 待加密的內容，為空時為回空
     * @return 加密后的base64格式的結果，出現異常時返回null
     */
    public static String encrypt(String content) {
        if (StringUtils.isEmpty(content)) {
            return null;
        }
        try {
            KeyGenerator keyGenerator = KeyGenerator.getInstance(ALGORITHM_NAME);
            SecureRandom secureRandom = SecureRandom.getInstance(RANDOM_KEY_ALGORITHM, RANDOM_KEY_ALGORITHM_PROVIDER);
            secureRandom.setSeed(DEFAULT_ENCRYPT_RULE.getBytes());
            keyGenerator.init(128, secureRandom);
            SecretKey originalKey = keyGenerator.generateKey();
            SecretKey secretKey = new SecretKeySpec(originalKey.getEncoded(), ALGORITHM_NAME);
            Cipher cipher = Cipher.getInstance(ALGORITHM_NAME);
            cipher.init(Cipher.ENCRYPT_MODE, secretKey);
            byte[] encrypted = cipher.doFinal(content.getBytes("utf-8"));
            String result = new String(Base64.getEncoder().encodeToString(encrypted));
            return  result;
        } catch (Exception e) {
            logger.error(e.getMessage(), e);
            return null;
        }
    }


    /**
     * 解密
     * @param encrypted 加密后的base64格式的密文
     * @return 解密后的原文，出現異常時返回null
     */
    public static String decrypt(String encrypted) {
        if (StringUtils.isEmpty(encrypted)) {
            return null;
        }
        try {
            KeyGenerator keyGenerator = KeyGenerator.getInstance(ALGORITHM_NAME);
            SecureRandom secureRandom = SecureRandom.getInstance(RANDOM_KEY_ALGORITHM, RANDOM_KEY_ALGORITHM_PROVIDER);
            secureRandom.setSeed(DEFAULT_ENCRYPT_RULE.getBytes());
            keyGenerator.init(128, secureRandom);
            SecretKey originalKey = keyGenerator.generateKey();
            SecretKey secretKey = new SecretKeySpec(originalKey.getEncoded(), ALGORITHM_NAME);
            Cipher cipher = Cipher.getInstance(ALGORITHM_NAME);
            cipher.init(Cipher.DECRYPT_MODE, secretKey);
            byte[] decrypted = cipher.doFinal(Base64.getDecoder().decode(encrypted));
            return new String(decrypted, "utf-8");
        } catch (Exception e) {
            logger.error(e.getMessage(), e);
            return null;
        }
    }