给定最终块未正确填充

Question

我正在尝试实现基于密码的加密算法，但出现此异常：javax.crypto.BadPaddingException：给定最终块，未正确填充可能是什么问题？（我是Java新手。）这是我的代码：public class PasswordCrypter {    private Key key;    public PasswordCrypter(String password)  {        try{            KeyGenerator generator;            generator = KeyGenerator.getInstance("DES");            SecureRandom sec = new SecureRandom(password.getBytes());            generator.init(sec);            key = generator.generateKey();        } catch (Exception e) {            e.printStackTrace();        }    }    public byte[] encrypt(byte[] array) throws CrypterException {        try{            Cipher cipher = Cipher.getInstance("DES/ECB/PKCS5Padding");            cipher.init(Cipher.ENCRYPT_MODE, key);            return cipher.doFinal(array);        } catch (Exception e) {             e.printStackTrace();        }        return null;    }    public byte[] decrypt(byte[] array) throws CrypterException{        try{            Cipher cipher = Cipher.getInstance("DES/ECB/PKCS5Padding");            cipher.init(Cipher.DECRYPT_MODE, key);            return cipher.doFinal(array);        } catch(Exception e ){            e.printStackTrace();        }        return null;    }}（JUnit测试）public class PasswordCrypterTest {    private static final byte[] MESSAGE = "Alpacas are awesome!".getBytes();    private PasswordCrypter[] passwordCrypters;    private byte[][] encryptedMessages;    @Before    public void setUp() {        passwordCrypters = new PasswordCrypter[] {            new PasswordCrypter("passwd"),            new PasswordCrypter("passwd"),            new PasswordCrypter("otherPasswd")        };        encryptedMessages = new byte[passwordCrypters.length][];        for (int i = 0; i < passwordCrypters.length; i++) {            encryptedMessages[i] = passwordCrypters[i].encrypt(MESSAGE);        }    }