mediaPlayer MediaPlayer 读取 字节数组

经过数天的研究和努力，我发现了解决方案，可能有助于节省别人的时间。这是我的答案。我改变了上面的代码逻辑，像这样

现在发生了什么，我能够成功地加密文件并将其保存在SD卡中，然后解密它播放。其他人不能播放音频

public class Main2Activity extends AppCompatActivity { 

    private String encryptedFileName = "encrypted_Audio.mp3"; 
    private static String algorithm = "AES"; 
    static SecretKey yourKey = null; 

    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_main2); 

     //saveFile("Hello From CoderzHeaven asaksjalksjals"); 
     try { 
      saveFile(getAudioFile()); 
     } catch (FileNotFoundException e) { 
      e.printStackTrace(); 
     } 
     decodeFile(); 

    } 

    public static SecretKey generateKey(char[] passphraseOrPin, byte[] salt) throws NoSuchAlgorithmException, InvalidKeySpecException { 
     // Number of PBKDF2 hardening rounds to use. Larger values increase 
     // computation time. You should select a value that causes computation 
     // to take >100ms. 
     final int iterations = 1000; 

     // Generate a 256-bit key 
     final int outputKeyLength = 256; 

     SecretKeyFactory secretKeyFactory = SecretKeyFactory.getInstance("PBKDF2WithHmacSHA1"); 
     KeySpec keySpec = new PBEKeySpec(passphraseOrPin, salt, iterations, outputKeyLength); 
     SecretKey secretKey = secretKeyFactory.generateSecret(keySpec); 
     return secretKey; 
    } 

    public static SecretKey generateKey() throws NoSuchAlgorithmException { 
     // Generate a 256-bit key 
     final int outputKeyLength = 256; 
     SecureRandom secureRandom = new SecureRandom(); 
     // Do *not* seed secureRandom! Automatically seeded from system entropy. 
     KeyGenerator keyGenerator = KeyGenerator.getInstance("AES"); 
     keyGenerator.init(outputKeyLength, secureRandom); 
     yourKey = keyGenerator.generateKey(); 
     return yourKey; 
    } 

    public static byte[] encodeFile(SecretKey yourKey, byte[] fileData) 
      throws Exception { 
     byte[] encrypted = null; 
     byte[] data = yourKey.getEncoded(); 
     SecretKeySpec skeySpec = new SecretKeySpec(data, 0, data.length, algorithm); 
     Cipher cipher = Cipher.getInstance(algorithm); 
     cipher.init(Cipher.ENCRYPT_MODE, skeySpec, new IvParameterSpec(
       new byte[cipher.getBlockSize()])); 
     encrypted = cipher.doFinal(fileData); 
     return encrypted; 
    } 

    public static byte[] decodeFile(SecretKey yourKey, byte[] fileData) 
      throws Exception { 
     byte[] decrypted = null; 
     Cipher cipher = Cipher.getInstance(algorithm); 
     cipher.init(Cipher.DECRYPT_MODE, yourKey, new IvParameterSpec(new byte[cipher.getBlockSize()])); 
     decrypted = cipher.doFinal(fileData); 
     return decrypted; 
    } 

    void saveFile(byte[] stringToSave) { 
     try { 
      File file = new File(Environment.getExternalStorageDirectory() + File.separator, encryptedFileName); 

      BufferedOutputStream bos = new BufferedOutputStream(new FileOutputStream(file)); 
      yourKey = generateKey(); 
      byte[] filesBytes = encodeFile(yourKey, stringToSave); 
      bos.write(filesBytes); 
      bos.flush(); 
      bos.close(); 
     } catch (FileNotFoundException e) { 
      e.printStackTrace(); 
     } catch (IOException e) { 
      e.printStackTrace(); 
     } catch (Exception e) { 
      e.printStackTrace(); 
     } 
    } 

    void decodeFile() { 

     try { 
      byte[] decodedData = decodeFile(yourKey, readFile()); 
      // String str = new String(decodedData); 
      //System.out.println("DECODED FILE CONTENTS : " + str); 
      playMp3(decodedData); 

     } catch (Exception e) { 
      e.printStackTrace(); 
     } 
    } 

    public byte[] readFile() { 
     byte[] contents = null; 

     File file = new File(Environment.getExternalStorageDirectory() 
       + File.separator, encryptedFileName); 
     int size = (int) file.length(); 
     contents = new byte[size]; 
     try { 
      BufferedInputStream buf = new BufferedInputStream(
        new FileInputStream(file)); 
      try { 
       buf.read(contents); 
       buf.close(); 
      } catch (IOException e) { 
       e.printStackTrace(); 
      } 
     } catch (FileNotFoundException e) { 
      e.printStackTrace(); 
     } 
     return contents; 
    } 

    public byte[] getAudioFile() throws FileNotFoundException 
    { 
     byte[] audio_data = null; 
     byte[] inarry = null; 
     AssetManager am = getAssets(); 
     try { 
      InputStream is = am.open("Sleep Away.mp3"); // use recorded file instead of getting file from assets folder. 
      int length = is.available(); 
      audio_data = new byte[length]; 
      int bytesRead; 
      ByteArrayOutputStream output = new ByteArrayOutputStream(); 
      while ((bytesRead = is.read(audio_data)) != -1) { 
       output.write(audio_data, 0, bytesRead); 
      } 
      inarry = output.toByteArray(); 
     } catch (IOException e) { 
      // TODO Auto-generated catch block 
      e.printStackTrace(); 
     } 
     return inarry; 

    } 

    private void playMp3(byte[] mp3SoundByteArray) { 

     try { 
      // create temp file that will hold byte array 
      File tempMp3 = File.createTempFile("kurchina", "mp3", getCacheDir()); 
      tempMp3.deleteOnExit(); 
      FileOutputStream fos = new FileOutputStream(tempMp3); 
      fos.write(mp3SoundByteArray); 
      fos.close(); 
      // Tried reusing instance of media player 
      // but that resulted in system crashes... 
      MediaPlayer mediaPlayer = new MediaPlayer(); 
      FileInputStream fis = new FileInputStream(tempMp3); 
      mediaPlayer.setDataSource(fis.getFD()); 
      mediaPlayer.prepare(); 
      mediaPlayer.start(); 
     } catch (IOException ex) { 
      ex.printStackTrace(); 

     } 

    } 
} 
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