使用AES算法对文件进行加密/解密的操作(JAVA)

很简单,直接上代码。

/**
     * 初始化 AES Cipher
     * @param sKey
     * @param cipherMode
     * @return
     */
    public Cipher initAESCipher(String sKey, int cipherMode) {
        //创建Key gen
        KeyGenerator keyGenerator = null;
        Cipher cipher = null;
        try {
            keyGenerator = KeyGenerator.getInstance("AES");
            keyGenerator.init(128, new SecureRandom(sKey.getBytes()));
            SecretKey secretKey = keyGenerator.generateKey();
            byte[] codeFormat = secretKey.getEncoded();
            SecretKeySpec key = new SecretKeySpec(codeFormat, "AES");
            cipher = Cipher.getInstance("AES");
            //初始化
            cipher.init(cipherMode, key);
        } catch (NoSuchAlgorithmException e) {
            e.printStackTrace();  //To change body of catch statement use File | Settings | File Templates.
        } catch (NoSuchPaddingException e) {
            e.printStackTrace();  //To change body of catch statement use File | Settings | File Templates.
        } catch (InvalidKeyException e) {
            e.printStackTrace();  //To change body of catch statement use File | Settings | File Templates.
        }
        return cipher;
    }


AES加密文件操作
/**
     * 对文件进行AES加密
     * @param sourceFile
     * @param fileType
     * @param sKey
     * @return
     */
    public File encryptFile(File sourceFile,String fileType, String sKey){
        //新建临时加密文件
        File encrypfile = null;
        InputStream inputStream = null;
        OutputStream outputStream = null;
        try {
            inputStream = new FileInputStream(sourceFile);
            encrypfile = File.createTempFile(sourceFile.getName(), fileType);
            outputStream = new FileOutputStream(encrypfile);
            Cipher cipher = initAESCipher(sKey,Cipher.ENCRYPT_MODE);
            //以加密流写入文件
            CipherInputStream cipherInputStream = new CipherInputStream(inputStream, cipher);
            byte[] cache = new byte[1024];
            int nRead = 0;
            while ((nRead = cipherInputStream.read(cache)) != -1) {
                outputStream.write(cache, 0, nRead);
                outputStream.flush();
            }
            cipherInputStream.close();
        }  catch (FileNotFoundException e) {
            e.printStackTrace();  //To change body of catch statement use File | Settings | File Templates.
        }  catch (IOException e) {
            e.printStackTrace();  //To change body of catch statement use File | Settings | File Templates.
        } finally {
            try {
                inputStream.close();
            } catch (IOException e) {
                e.printStackTrace();  //To change body of catch statement use File | Settings | File Templates.
            }
            try {
                outputStream.close();
            } catch (IOException e) {
                e.printStackTrace();  //To change body of catch statement use File | Settings | File Templates.
            }
        }
        return encrypfile;
    }


AES解密文件
/**
     * AES方式解密文件
     * @param sourceFile
     * @return
     */
    public File decryptFile(File sourceFile,String fileType,String sKey){
        File decryptFile = null;
        InputStream inputStream = null;
        OutputStream outputStream = null;
        try {
            decryptFile = File.createTempFile(sourceFile.getName(),fileType);
            Cipher cipher = initAESCipher(sKey,Cipher.DECRYPT_MODE);
            inputStream = new FileInputStream(sourceFile);
            outputStream = new FileOutputStream(decryptFile);
            CipherOutputStream cipherOutputStream = new CipherOutputStream(outputStream, cipher);
            byte [] buffer = new byte [1024];
            int r;
            while ((r = inputStream.read(buffer)) >= 0) {
                cipherOutputStream.write(buffer, 0, r);
            }
            cipherOutputStream.close();
        } catch (IOException e) {
            e.printStackTrace();  //To change body of catch statement use File | Settings | File Templates.
        }finally {
            try {
                inputStream.close();
            } catch (IOException e) {
                e.printStackTrace();  //To change body of catch statement use File | Settings | File Templates.
            }
            try {
                outputStream.close();
            } catch (IOException e) {
                e.printStackTrace();  //To change body of catch statement use File | Settings | File Templates.
            }
        }
        return decryptFile;
    }


注意:对文件的读写操作一定要指定编码,否则会导致很多未知的编码问题。


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转载于:https://blog.csdn.net/shiwenqing/article/details/7987145 
 

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