Background: there is a demand now is to write a interface receive encrypted information from other systems, need to decrypt the reprocessing
Encryption algorithm is known:
AES/the ECB/pkcs5padding/128 - bit data blocks/password: 12345678901234567890123456789012/base64 output/utf8 character set
Test on online website:

This configuration can be normal decryption

Then I start trying to Java implementation
Key code is as follows:

 
Private static String key="12345678901234567890123456789012"; 
Private static String mode="AES/the ECB/PKCS5Padding"; 
Public static String decodeMsg (String MSG) throws NoSuchPaddingException, NoSuchAlgorithmException, InvalidKeyException, BadPaddingException, IllegalBlockSizeException, UnsupportedEncodingException, InvalidKeySpecException {
Cipher Cipher=Cipher. GetInstance (mode); 
Cipher. The init (cipher DECRYPT_MODE, getSecretKey (key));//initialize 
Byte [] msgbyte=base64 (MSG); 
Result=cipher byte []. DoFinal (msgbyte); 
Return a new String (result);//decryption 
} 
Public static byte [] base64 (String STR) {
Return Base64. GetDecoder (). The decode (STR); 
} 
Private static SecretKeySpec getSecretKey (final String password) {
//returns the algorithm to generate the key generator KeyGenerator object 
KeyGenerator kg=null; 
Try {
Kg=KeyGenerator. GetInstance (AES, ""); 
Byte [] keyBytes=password. GetBytes (); 
SecureRandom SecureRandom=SecureRandom. GetInstance (" SHA1PRNG "); 
SecureRandom. SetSeed (keyBytes); 
//AES for key length of 128 
Kg. The init (128, secureRandom); 
A key generated//
SecretKey SecretKey=kg. GenerateKey (); 
Return new SecretKeySpec (secretKey. GetEncoded (), "AES");//converted to AES private key 
{} the catch (NoSuchAlgorithmException ex) 
//Logger. GetLogger (AESUtil. Class. GetName ()). The log (Level. SEVERE, null, ex); 
} 
return null; 
} 

Test has been an exception is thrown when
Javax.mail. Crypto. BadPaddingException: Given the final block not properly padded

I first make AES, for not familiar with this, where is can't see the problem is,

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