JA V A实现AES加密算法代码近些年DES使用越来越少，原因就在于其使用56位密钥，比较容易被破解，近些年来逐渐被AES替代，AES已经变成目前对称加密中最流行算法之一；AES可以使用128、192、和256位密钥，并且用128位分组加密和解密数据。

本文就简单介绍如何通过JA VA实现AES加密。

1. JA V A 实现闲话少许，掠过AES加密原理及算法，关于这些直接搜索专业网站吧，我们直接看JA V A的具体实现。

1.1 加密代码有详细解释，不多废话。

/*** 加密** @param content 需要加密的内容* @param password 加密密码* @return*/public static byte[] encrypt(String content, String password) {try {KeyGenerator kgen = KeyGenerator.getInstance("AES"); kgen.init(128, new SecureRandom(password.getBytes())); SecretKey secretKey = kgen.generateKey();byte[] enCodeFormat = secretKey.getEncoded();SecretKeySpec key = new SecretKeySpec(enCodeFormat, "AES");Cipher cipher = Cipher.getInstance("AES");// 创建密码器byte[] byteContent = content.getBytes("utf-8");cipher.init(Cipher.ENCRYPT_MODE, key);// 初始化byte[] result = cipher.doFinal(byteContent);return result; // 加密} catch (NoSuchAlgorithmException e){ e.printStackTrace();} catch (NoSuchPaddingException e) { e.printStackTrace();} catch (InvalidKeyException e) { e.printStackTrace();} catch (UnsupportedEncodingException e){ e.printStackTrace();} catch (IllegalBlockSizeException e) { e.printStackTrace();} catch (BadPaddingException e) { e.printStackTrace();} return null;}/*** 加密** @param content 需要加密的内容* @param password 加密密码* @return*/public static byte[] encrypt(String content, String password) {try {KeyGenerator kgen = KeyGenerator.getInstance("AES");kgen.init(128, new SecureRandom(password.getBytes()));SecretKey secretKey = kgen.generateKey();byte[] enCodeFormat = secretKey.getEncoded();SecretKeySpec key = new SecretKeySpec(enCodeFormat, "AES");Cipher cipher = Cipher.getInstance("AES");// 创建密码器byte[] byteContent = content.getBytes("utf-8");cipher.init(Cipher.ENCRYPT_MODE, key);// 初始化byte[] result = cipher.doFinal(byteContent);return result; // 加密} catch (NoSuchAlgorithmException e)(NoSuchPaddingException e) { e.printStackTrace();} catch (InvalidKeyException e) { e.printStackTrace();} catch (UnsupportedEncodingException e){ e.printStackTrace();} catch (IllegalBlockSizeException e) { e.printStackTrace();} catch (BadPaddingException e) { e.printStackTrace();} return null;} 2.2 解密代码有详细注释，不多废话注意：解密的时候要传入byte数组view plaincopy to clipboardprint?/**解密* @param content 待解密内容* @param password 解密密钥* @return*/ public static byte[] decrypt(byte[] content, String password) {try {KeyGenerator kgen =KeyGenerator.getInstance("AES");kgen.init(128, new SecureRandom(password.getBytes()));SecretKey secretKey = kgen.generateKey();byte[] enCodeFormat = secretKey.getEncoded();SecretKeySpec key = new SecretKeySpec(enCodeFormat, "AES");Cipher cipher = Cipher.getInstance("AES");// 创建密码器cipher.init(Cipher.DECRYPT_MODE, key);// 初始化byte[] result = cipher.doFinal(content);return result; // 加密} catch (NoSuchAlgorithmException e)(NoSuchPaddingException e) { e.printStackTrace();} catch (InvalidKeyException e) { e.printStackTrace();} catch (IllegalBlockSizeException e){ e.printStackTrace();} catch (BadPaddingException e) { e.printStackTrace();}return null;}/**解密* @param content 待解密内容* @param password 解密密钥* @return*/public static byte[] decrypt(byte[] content, String password) {try {KeyGenerator kgen = KeyGenerator.getInstance("AES"); kgen.init(128, new SecureRandom(password.getBytes())); SecretKey secretKey = kgen.generateKey();byte[] enCodeFormat = secretKey.getEncoded();SecretKeySpec key = new SecretKeySpec(enCodeFormat, "AES");Cipher cipher = Cipher.getInstance("AES");// 创建密码器cipher.init(Cipher.DECRYPT_MODE, key);// 初始化byte[] result = cipher.doFinal(content);return result; // 加密} catch (NoSuchAlgorithmException e){ e.printStackTrace();} catch (NoSuchPaddingException e) { e.printStackTrace();} catch (InvalidKeyException e) { e.printStackTrace();} catch (IllegalBlockSizeException e){ e.printStackTrace();} catch (BadPaddingException e) { e.printStackTrace();}return null;}2.3 测试代码String content = "test";String password = "12345678";//加密System.out.println("加密前：" + content);byte[] encryptResult = encrypt(content, password); //解密byte[] decryptResult =decrypt(encryptResult,password);System.out.println("解密后：" + new String(decryptResult));String content = "test"; String password = "12345678";//加密System.out.println("加密前：" + content);byte[] encryptResult = encrypt(content, password);//解密byte[] decryptResult = decrypt(encryptResult,password); System.out.println("解密后：" + new String(decryptResult));输出结果如下：加密前：test解密后：test 2.4 容易出错的地方但是如果我们将测试代码修改一下，如下：String content = "test";String password = "12345678";//加密System.out.println("加密前：" + content);byte[] encryptResult = encrypt(content, password); try {String encryptResultStr = newString(encryptResult,"utf-8");//解密byte[] decryptResult =decrypt(encryptResultStr.getBytes("utf-8"),password);System.out.println("解密后：" + newString(decryptResult));} catch (UnsupportedEncodingException e){ e.printStackTrace();}String content = "test"; String password = "12345678";//加密System.out.println("加密前：" + content);byte[] encryptResult = encrypt(content, password);try{String encryptResultStr = newString(encryptResult,"utf-8");//解密byte[] decryptResult =decrypt(encryptResultStr.getBytes("utf-8"),password); System.out.println("解密后：" + newString(decryptResult));} catch (UnsupportedEncodingException e){ e.printStackTrace();}则，系统会报出如下异常：javax.crypto.IllegalBlockSizeException: Input length must be multiple of 16 when decrypting with padded cipher at com.sun.crypto.provider.SunJCE_f.b(DashoA13*..)at com.sun.crypto.provider.SunJCE_f.b(DashoA13*..)at com.sun.crypto.provider.AESCipher.engineDoFinal(DashoA13* ..)at javax.crypto.Cipher.doFinal(DashoA13*..)这主要是因为加密后的byte数组是不能强制转换成字符串的，换言之：字符串和byte数组在这种情况下不是互逆的；要避免这种情况，我们需要做一些修订，可以考虑将二进制数据转换成十六进制表示，主要有如下两个方法： 2.4.1将二进制转换成16进制/**将二进制转换成16进制* @param buf* @return*/public static StringparseByte2HexStr(byte buf[]) {StringBuffer sb = new StringBuffer();for (int i = 0; i String hex = Integer.toHexString(buf[i] & 0xFF);if (hex.length() == 1) {hex = '0' + hex;}sb.append(hex.toUpperCase());}returnsb.toString();}/**将二进制转换成16进制*@param buf* @return*/public static String parseByte2HexStr(byte buf[]) {StringBuffer sb = new StringBuffer();for (int i = 0; i String hex = Integer.toHexString(buf[i] & 0xFF);if (hex.length() == 1) {hex = '0' + hex;}sb.append(hex.toUpperCase());}returnsb.toString();} 2.4.2 将16进制转换为二进制/**将16进制转换为二进制* @param hexStr* @return */public static byte[] parseHexStr2Byte(String hexStr){if (hexStr.length() return null;byte[] result = new byte[hexStr.length()/2];for (int i = 0;i int high =Integer.parseInt(hexStr.substring(i*2, i*2+1), 16);int low = Integer.parseInt(hexStr.substring(i*2+1, i*2+2), 16);result[i] = (byte) (high * 16 + low);}return result;}/**将16进制转换为二进制* @param hexStr*@return*/public static byte[] parseHexStr2Byte(String hexStr) {if (hexStr.length() return null;byte[] result = new byte[hexStr.length()/2];for (int i = 0;i int high = Integer.parseInt(hexStr.substring(i*2, i*2+1), 16);int low = Integer.parseInt(hexStr.substring(i*2+1, i*2+2), 16); result[i] = (byte) (high * 16 + low);}return result;}然后，我们再修订以上测试代码，如下：String content = "test";String password = "12345678";//加密System.out.println("加密前：" + content);byte[] encryptResult = encrypt(content, password);String encryptResultStr = parseByte2HexStr(encryptResult); System.out.println("加密后：" + encryptResultStr);//解密byte[] decryptFrom = parseHexStr2Byte(encryptResultStr);byte[] decryptResult = decrypt(decryptFrom,password); System.out.println("解密后：" + new String(decryptResult)); String content = "test";String password = "12345678";//加密System.out.println("加密前：" + content);byte[] encryptResult = encrypt(content, password);StringencryptResultStr = parseByte2HexStr(encryptResult); System.out.println("加密后：" + encryptResultStr);//解密byte[] decryptFrom = parseHexStr2Byte(encryptResultStr);byte[] decryptResult = decrypt(decryptFrom,password); System.out.println("解密后：" + new String(decryptResult));测试结果如下：加密前：test加密后：73C58BAFE578C59366D8C995CD0B9D6D解密后：test 2.5 另外一种加密方式还有一种加密方式，大家可以参考如下：/*** 加密** @param content 需要加密的内容* @param password 加密密码*@return*/public static byte[] encrypt2(String content, String password) {try {SecretKeySpec key = new SecretKeySpec(password.getBytes(), "AES");Cipher cipher = Cipher.getInstance("AES/ECB/NoPadding");byte[] byteContent = content.getBytes("utf-8");cipher.init(Cipher.ENCRYPT_MODE, key);// 初始化byte[] result = cipher.doFinal(byteContent);return result; // 加密} catch (NoSuchAlgorithmException e){ e.printStackTrace();} catch (NoSuchPaddingException e) { e.printStackTrace();} catch (InvalidKeyException e) { e.printStackTrace();} catch (UnsupportedEncodingException e){ e.printStackTrace();} catch (IllegalBlockSizeException e) { e.printStackTrace();} catch (BadPaddingException e) { e.printStackTrace();} return null;}/*** 加密** @param content 需要加密的内容* @param password 加密密码* @return*/public static byte[] encrypt2(String content, String password) {try {SecretKeySpec key = new SecretKeySpec(password.getBytes(), "AES");Cipher cipher = Cipher.getInstance("AES/ECB/NoPadding");byte[] byteContent = content.getBytes("utf-8");cipher.init(Cipher.ENCRYPT_MODE, key);// 初始化byte[] result = cipher.doFinal(byteContent);return result; // 加密} catch (NoSuchAlgorithmException e){ e.printStackTrace();} catch (NoSuchPaddingException e) { e.printStackTrace();} catch (InvalidKeyException e) { e.printStackTrace();} catch (UnsupportedEncodingException e){ e.printStackTrace();} catch (IllegalBlockSizeException e) { e.printStackTrace();} catch (BadPaddingException e) { e.printStackTrace();} return null;}这种加密方式有两种限制密钥必须是16位的待加密内容的长度必须是16的倍数，如果不是16的倍数，就会出如下异常：javax.crypto.IllegalBlockSizeException: Input length not multiple of 16 bytes atcom.sun.crypto.provider.SunJCE_f.a(DashoA13*..)at com.sun.crypto.provider.SunJCE_f.b(DashoA13*..)at com.sun.crypto.provider.SunJCE_f.b(DashoA13*..)at com.sun.crypto.provider.AESCipher.engineDoFinal(DashoA13* ..)at javax.crypto.Cipher.doFinal(DashoA13*..)要解决如上异常，可以通过补全传入加密内容等方式进行避免。