앱)aesciperutil 자바 common 코드

static String key = "~~~~~~";


byte[] hexToByteArray(String hex){
       if( hex == null || hex.length() == 0){
     return null;
}

      byte[] ba = new byte[hex.length() / 2];
       for( int i =0 ; i<ba.length; i++){
            ba[i] = (byte) Integer.parseInt(hex.substring(2*i, 2*i+2), 16);
       }
       return ba;
}


String byteArrayToHex(byte[] ba){
      if( ba == null || ba.length == 0){
          return null;
      }
    
       StringBuffer sb = new StringBuffer(ba.length*2);
        String hexNumber;

         for( int x = 0; x<ba.length; x++){
                hexNumber = "0" + Integer.toHexString(0xff & ba[x]);
                sb.append(hexNumber.substring(hexNumber.length() - 2);
          }
          return sb.toString();
}


String encrypt(String message){
        SecretKeySpec skeySpec = new SecretKeySpec(key.getByte(), "AES");

         Cipher cipher = Cipher.getInstance("AES");
          chpher.init(Cipher.ENCRYPT_MODE, skeySpec);
    
       byte[] encrypted = cipher.doFinal(message.getByte());
       return byteArrayToHex(encrypted);
}


String decrypt(String encrypted){
        SecretKeySpec skeySpec = new SecretKeySpec(key.getBytes(), "AES");
         
          Cipher cipher = Cipher.getInstance("AES");
          cipher.init(Cipher.DECRYPT_MODE, skeySpec);
          byte[] original = cipher.doFinal(hexToByteArray(encrypted));
          String originalString = new String(original);
          return originalString;
}


public static void main(String[] args){
        String enc = encrypt("~~~~~");
       

          String dec = decrypt("~~~~~");
}