方法1：此方法自ApacheCommons编解码器的1.4版起可用。如果手机的操作系统只有旧版本的编解码器软件包，该方法将不可用。或者，我们可以使用旧版本中存在的方法。
而不是：

String encodedString = Base64.encodeBase64String(bytes);

用途：

String encodedString = new String(Base64.encodeBase64(bytes));

对于解码，而不是：

byte[] bytes = Base64.decodeBase64(encodedString);

用途：

byte[] bytes = Base64.decodeBase64(encodedString.getBytes());

方法2：您还可以使用下面完整的代码进行加密和解密。

import android.util.Base64;
import org.apache.commons.codec.DecoderException;
import org.apache.commons.codec.binary.Hex;
import javax.crypto.*;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.PBEKeySpec;
import javax.crypto.spec.SecretKeySpec;
import java.io.UnsupportedEncodingException;
import java.security.InvalidAlgorithmParameterException;
import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;
import java.security.spec.InvalidKeySpecException;
import java.security.spec.KeySpec;

public class AesUtil {
private  int keySize = 256;
private  int iterationCount =  1000 ;
private  Cipher cipher;

private final String salt = "36e8fc9a6adf090665f459a7ad1b864d";
private final String iv = "ab00b7ea4e88500f2f0a17a7b5c7bcb1";
private final String passphrase = "ArknRQxD1YgaSFRHrjYazX7JMrlRxTERdkQx0dhENVlz";

public AesUtil() {
    try {
        cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
    }
    catch (NoSuchAlgorithmException | NoSuchPaddingException e) {
        throw fail(e);
    }
}

public String encrypt(String plaintext) {
    try {
        SecretKey key = generateKey(salt, passphrase);
        byte[] encrypted = doFinal(Cipher.ENCRYPT_MODE, key, iv, plaintext.getBytes("UTF-8"));
        return Base64.encodeToString(encrypted, Base64.DEFAULT);
    }
    catch (UnsupportedEncodingException e) {
        throw fail(e);
    }
}

public String decrypt(String salt, String iv, String passphrase, String ciphertext) {
    try {
        SecretKey key = generateKey(salt, passphrase);
        byte[] decrypted = doFinal(Cipher.DECRYPT_MODE, key, iv, base64(ciphertext));
        return new String(decrypted, "UTF-8");
    } catch (Exception e) {
        throw fail(e);
    }
}

private byte[] doFinal(int encryptMode, SecretKey key, String iv, byte[] bytes) {
    try {
        cipher.init(encryptMode, key, new IvParameterSpec(hex(iv)));
        return cipher.doFinal(bytes);
    } catch (InvalidKeyException
            | InvalidAlgorithmParameterException
            | IllegalBlockSizeException
            | BadPaddingException e) {
        throw fail(e);
    }
}

public SecretKey generateKey(String salt, String passphrase) {
    try {
        SecretKeyFactory factory = SecretKeyFactory.getInstance("PBKDF2WithHmacSHA1");
        KeySpec spec = new PBEKeySpec(passphrase.toCharArray(), hex(salt), iterationCount, keySize);
        SecretKey key = new SecretKeySpec(factory.generateSecret(spec).getEncoded(), "AES");
        return key;
    }
    catch (NoSuchAlgorithmException | InvalidKeySpecException e) {
        return null;
    }
}

public static byte[] base64(String str) {
    return Base64.decode(str, Base64.DEFAULT);
}

public static byte[] hex(String str) {
    try {
        return Hex.decodeHex(str.toCharArray());
    }
    catch (DecoderException e) {
        throw fail(e);
    }
}

private IllegalStateException fail(Exception e) {
    e.printStackTrace();
    return null;
}

private static IllegalStateException fail(DecoderException e) {
    e.printStackTrace();
    return null;
} }