Aes加/解密工具类 --Java

• 一、加/解密流程图
• 二、生成密钥
• 三、字符串加密解密
• • 1.字符串加密
  • 2.字符串解密
• 四、文件加密解密
• • 1.文件加密
  • 2.文件解密
• 五、测试

代码如下（示例）：

	
    public static String generateKey(String seed, int keySize) throws Exception {
        KeyGenerator keyGenerator = KeyGenerator.getInstance("AES");
        SecureRandom secureRandom;
        if (seed != null && !"".equals(seed)) {
            secureRandom = new SecureRandom(seed.getBytes());
        } else {
            secureRandom = new SecureRandom();
        }

        keyGenerator.init(keySize, secureRandom);
        SecretKey secretKey = keyGenerator.generateKey();
        return Base64.encodeBase64String(secretKey.getEncoded());
    }

代码如下（示例）：

	
    public static String encrypt(String data, String key) throws Exception {
        Key k = toKey(Base64.decodeBase64(key));
        byte[] raw = k.getEncoded();
        SecretKeySpec secretKeySpec = new SecretKeySpec(raw, "AES");
        Cipher cipher = Cipher.getInstance("AES");
        cipher.init(1, secretKeySpec);
        byte[] encypted = cipher.doFinal(data.getBytes());
        return Base64.encodeBase64String(encypted);
    }

代码如下（示例）：

	
    public static String decrypt(String data, String key) throws Exception {
        Key k = toKey(Base64.decodeBase64(key));
        byte[] raw = k.getEncoded();
        SecretKeySpec secretKeySpec = new SecretKeySpec(raw, "AES");
        Cipher cipher = Cipher.getInstance("AES");
        cipher.init(2, secretKeySpec);
        byte[] encryptedBytes = Base64.decodeBase64(data);
        byte[] originalBytes = cipher.doFinal(encryptedBytes);
        return new String(originalBytes);
    }

代码如下（示例）：

	
    public static int encryptFile(String key, File sourceFile, File targetFile) throws Exception {
        if (sourceFile.exists() && sourceFile.isFile()) {
            if (!targetFile.getParentFile().exists()) {
                targetFile.getParentFile().mkdirs();
            }

            targetFile.createNewFile();
            InputStream in = new FileInputStream(sourceFile);
            OutputStream out = new FileOutputStream(targetFile);
            Key k = toKey(Base64.decodeBase64(key));
            byte[] raw = k.getEncoded();
            SecretKeySpec secretKeySpec = new SecretKeySpec(raw, "AES");
            Cipher cipher = Cipher.getInstance("AES");
            cipher.init(1, secretKeySpec);
            CipherInputStream cin = new CipherInputStream(in, cipher);
            byte[] cache = new byte[1024];
            boolean var11 = false;

            int nRead;
            while ((nRead = cin.read(cache)) != -1) {
                out.write(cache, 0, nRead);
                out.flush();
            }

            out.close();
            cin.close();
            in.close();
            log.debug("Encrypted successfully!!");
            return 1;
        } else {
            log.debug("Encrypted Failed," + sourceFile.getAbsolutePath() + "文件不存在!!");
            return 1;
        }
    }

代码如下（示例）：

	
    public static int decryptFile(String key, File sourceFile, File targetFile) throws Exception {
        if (sourceFile.exists() && sourceFile.isFile()) {
            if (!targetFile.getParentFile().exists()) {
                targetFile.getParentFile().mkdirs();
            }

            targetFile.createNewFile();
            FileInputStream in = new FileInputStream(sourceFile);
            FileOutputStream out = new FileOutputStream(targetFile);
            Key k = toKey(Base64.decodeBase64(key));
            byte[] raw = k.getEncoded();
            SecretKeySpec secretKeySpec = new SecretKeySpec(raw, "AES");
            Cipher cipher = Cipher.getInstance("AES");
            cipher.init(2, secretKeySpec);
            CipherOutputStream cout = new CipherOutputStream(out, cipher);
            byte[] cache = new byte[1024];
            boolean var11 = false;

            int nRead;
            while ((nRead = in.read(cache)) != -1) {
                cout.write(cache, 0, nRead);
                cout.flush();
            }

            cout.close();
            out.close();
            in.close();
            log.debug("Decrypted successfully!!");
            return 0;
        } else {
            log.debug("Decrypted Failed," + sourceFile.getAbsolutePath() + "文件不存在!!");
            return 1;
        }
    }

代码如下（示例）：

 public static void main(String[] args) {
        //密钥种子
        String seed = "123456";
        //salt盐值
        String salt = "tomy";
        //key size
        int keySize = 128;
        //secret key
        String key = "";
        try {
           //生成secret key
            key = GenerateKeyUtil.generateKey(seed + salt, keySize);
            System.out.println(key);
            //执行字符串加密
            String encrypt = AESUtil.encrypt("7895455", key);
            System.out.println(encrypt);
            //执行字符串解密
            String decrypt = AESUtil.decrypt(encrypt, key);
            System.out.println(decrypt);
            File sourceFile = new File("C:\Users\Desktop\1.png");
            File targetFile = new File("C:\Users\Desktop\2.png");
            File targetFile1 = new File("C:\Users\Desktop\3.png");
            //执行文件加密
            encryptFile(key, sourceFile, targetFile);
            //执行文件解密
            decryptFile(key, targetFile, targetFile1);
        } catch (Exception e) {
            e.printStackTrace();
        }

    }