Java Code Examples for android.content.res.AssetFileDescriptor#getFileDescriptor()

@NonNull
static RandomAccessFile create(AssetFileDescriptor afd, String mode) throws IOException {
    if (afd == null) {
        throw new IOException("AssetFileDescriptor is null");
    }

    checkReflection();

    try {
        FileDescriptor fd = afd.getFileDescriptor();
        if (fd == null) {
            throw new IOException("Can't get FileDescriptor");
        }

        TrickRandomAccessFile file = create(fd, mode);
        file.mAfd = afd;
        return file;
    } catch (IOException e) {
        // Close AssetFileDescriptor if failed
        afd.close();
        throw e;
    }
}
 

private MappedByteBuffer loadModelFile(AssetManager assetManager, String modelPath) throws IOException {
    AssetFileDescriptor fileDescriptor = assetManager.openFd(modelPath);
    FileInputStream inputStream = new FileInputStream(fileDescriptor.getFileDescriptor());
    FileChannel fileChannel = inputStream.getChannel();
    long startOffset = fileDescriptor.getStartOffset();
    long declaredLength = fileDescriptor.getDeclaredLength();
    return fileChannel.map(FileChannel.MapMode.READ_ONLY, startOffset, declaredLength);
}
 

private void setDataSourceInternalContentUri(Context context, Uri uri)
        throws IOException, IllegalArgumentException, SecurityException, IllegalStateException {
    final ContentResolver cr = context.getContentResolver();

    AssetFileDescriptor afd = cr.openAssetFileDescriptor(uri, "r");
    FileDescriptor fd = afd.getFileDescriptor();
    final int nativeFD;

    try {
        nativeFD = checkAndObtainNativeFileDescriptor(fd);
    } catch (IllegalArgumentException e) {
        closeQuietly(afd);
        throw e;
    }

    final int result;
    final long declLength = afd.getDeclaredLength();
    final long startOffset = afd.getStartOffset();
    if (declLength < 0) {
        result = setDataSourceFdImplNative(mNativeHandle, nativeFD);
    } else {
        result = setDataSourceFdImplNative(
                mNativeHandle, nativeFD, startOffset, declLength);
    }

    parseResultAndThrowException(result);

    mContentAssetFd = afd;
}
 

/** Memory-map the model file in Assets. */
private static MappedByteBuffer loadModelFile(AssetManager assets, String modelFilename)
    throws IOException {
  AssetFileDescriptor fileDescriptor = assets.openFd(modelFilename);
  FileInputStream inputStream = new FileInputStream(fileDescriptor.getFileDescriptor());
  FileChannel fileChannel = inputStream.getChannel();
  long startOffset = fileDescriptor.getStartOffset();
  long declaredLength = fileDescriptor.getDeclaredLength();
  return fileChannel.map(FileChannel.MapMode.READ_ONLY, startOffset, declaredLength);
}
 

protected MappedByteBuffer loadMappedFile(String filePath) throws IOException {
  AssetFileDescriptor fileDescriptor = assetManager.openFd(this.directoryName + "/" + filePath);
  FileInputStream inputStream = new FileInputStream(fileDescriptor.getFileDescriptor());
  FileChannel fileChannel = inputStream.getChannel();
  long startOffset = fileDescriptor.getStartOffset();
  long declaredLength = fileDescriptor.getDeclaredLength();
  return fileChannel.map(MapMode.READ_ONLY, startOffset, declaredLength);
}
 

/**
 * Memory-map the model file in Assets.
 */
public static MappedByteBuffer loadModelFile(Context context, String modelFile)
        throws IOException {
    AssetFileDescriptor fileDescriptor = context.getAssets().openFd(modelFile);
    FileInputStream inputStream = new FileInputStream(fileDescriptor.getFileDescriptor());
    FileChannel fileChannel = inputStream.getChannel();
    long startOffset = fileDescriptor.getStartOffset();
    long declaredLength = fileDescriptor.getDeclaredLength();
    return fileChannel.map(FileChannel.MapMode.READ_ONLY, startOffset, declaredLength);
}
 

/**
 * Creates drawable from AssetFileDescriptor.
 * Convenience wrapper for {@link pl.droidsonroids.gif.GifDrawable#GifDrawable(java.io.FileDescriptor)}
 * @param afd source
 * @throws NullPointerException if afd is null
 * @throws java.io.IOException when opening failed
 */
public GifDrawable ( AssetFileDescriptor afd ) throws IOException
{
	if (afd==null)
		throw new NullPointerException( "Source is null" );		
	FileDescriptor fd = afd.getFileDescriptor();
	mGifInfoPtr = openFd( mMetaData, fd, afd.getStartOffset() );
	mColors = new int[ mMetaData[ 0 ] * mMetaData[ 1 ] ];
	checkError();
}
 

/**
 * Memory-map the model file in Assets.
 */
public static MappedByteBuffer loadModelFile(Context context, String modelFile)
        throws IOException {
    AssetFileDescriptor fileDescriptor = context.getAssets().openFd(modelFile);
    FileInputStream inputStream = new FileInputStream(fileDescriptor.getFileDescriptor());
    FileChannel fileChannel = inputStream.getChannel();
    long startOffset = fileDescriptor.getStartOffset();
    long declaredLength = fileDescriptor.getDeclaredLength();
    return fileChannel.map(FileChannel.MapMode.READ_ONLY, startOffset, declaredLength);
}
 

/**
 * Memory-map the model file in Assets.
 */
public static MappedByteBuffer loadModelFile(Context context, String modelFile)
        throws IOException {
    AssetFileDescriptor fileDescriptor = context.getAssets().openFd(modelFile);
    FileInputStream inputStream = new FileInputStream(fileDescriptor.getFileDescriptor());
    FileChannel fileChannel = inputStream.getChannel();
    long startOffset = fileDescriptor.getStartOffset();
    long declaredLength = fileDescriptor.getDeclaredLength();
    return fileChannel.map(FileChannel.MapMode.READ_ONLY, startOffset, declaredLength);
}
 

/** Memory-map the model file in Assets. */
private static MappedByteBuffer loadModelFile(AssetManager assets, String modelFilename)
    throws IOException {
  AssetFileDescriptor fileDescriptor = assets.openFd(modelFilename);
  FileInputStream inputStream = new FileInputStream(fileDescriptor.getFileDescriptor());
  FileChannel fileChannel = inputStream.getChannel();
  long startOffset = fileDescriptor.getStartOffset();
  long declaredLength = fileDescriptor.getDeclaredLength();
  return fileChannel.map(FileChannel.MapMode.READ_ONLY, startOffset, declaredLength);
}
 

/** Memory-map the model file in Assets. */
private MappedByteBuffer loadModelFile(Activity activity) throws IOException {
  AssetFileDescriptor fileDescriptor = activity.getAssets().openFd(MODEL_PATH);
  FileInputStream inputStream = new FileInputStream(fileDescriptor.getFileDescriptor());
  FileChannel fileChannel = inputStream.getChannel();
  long startOffset = fileDescriptor.getStartOffset();
  long declaredLength = fileDescriptor.getDeclaredLength();
  return fileChannel.map(FileChannel.MapMode.READ_ONLY, startOffset, declaredLength);
}
 

/** Memory-map the model file in Assets. */
private MappedByteBuffer loadModelFile(Activity activity) throws IOException {
    AssetFileDescriptor fileDescriptor = activity.getAssets().openFd(getModelPath());
    FileInputStream inputStream = new FileInputStream(fileDescriptor.getFileDescriptor());
    FileChannel fileChannel = inputStream.getChannel();
    long startOffset = fileDescriptor.getStartOffset();
    long declaredLength = fileDescriptor.getDeclaredLength();
    return fileChannel.map(FileChannel.MapMode.READ_ONLY, startOffset, declaredLength);
}
 

/** Memory-map the model file in Assets. */
private static MappedByteBuffer loadModelFile(AssetManager assets, String modelFilename)
    throws IOException {
  AssetFileDescriptor fileDescriptor = assets.openFd(modelFilename);
  FileInputStream inputStream = new FileInputStream(fileDescriptor.getFileDescriptor());
  FileChannel fileChannel = inputStream.getChannel();
  long startOffset = fileDescriptor.getStartOffset();
  long declaredLength = fileDescriptor.getDeclaredLength();
  return fileChannel.map(FileChannel.MapMode.READ_ONLY, startOffset, declaredLength);
}
 

/**
 * Memory-map the model file in Assets.
 */
private static MappedByteBuffer loadModelFile(AssetManager assets, String modelFilename)
        throws IOException {
    AssetFileDescriptor fileDescriptor = assets.openFd(modelFilename);
    FileInputStream inputStream = new FileInputStream(fileDescriptor.getFileDescriptor());
    FileChannel fileChannel = inputStream.getChannel();
    long startOffset = fileDescriptor.getStartOffset();
    long declaredLength = fileDescriptor.getDeclaredLength();
    return fileChannel.map(FileChannel.MapMode.READ_ONLY, startOffset, declaredLength);
}
 

/** Memory-map the model file in Assets. */
public MappedByteBuffer loadModelFile() throws IOException {
    AssetFileDescriptor fileDescriptor = ASSET_MANAGER.openFd(MODEL_PATH);
    FileInputStream inputStream = new FileInputStream(fileDescriptor.getFileDescriptor());
    FileChannel fileChannel = inputStream.getChannel();
    long startOffset = fileDescriptor.getStartOffset();
    long declaredLength = fileDescriptor.getDeclaredLength();
    return fileChannel.map(FileChannel.MapMode.READ_ONLY, startOffset, declaredLength);
}
 

protected MappedByteBuffer loadModelFile(AssetManager assetManager, String modelPath) throws IOException {
    AssetFileDescriptor fileDescriptor = assetManager.openFd(modelPath);
    FileInputStream inputStream = new FileInputStream(fileDescriptor.getFileDescriptor());
    FileChannel fileChannel = inputStream.getChannel();
    long startOffset = fileDescriptor.getStartOffset();
    long declaredLength = fileDescriptor.getDeclaredLength();
    return fileChannel.map(FileChannel.MapMode.READ_ONLY, startOffset, declaredLength);
}
 

/**
 * 加载模型文件
 * @param assetManager
 * @param modelPath
 * @return
 * @throws IOException
 */
public static MappedByteBuffer loadModelFile(AssetManager assetManager, String modelPath) throws IOException {
    AssetFileDescriptor fileDescriptor = assetManager.openFd(modelPath);
    FileInputStream inputStream = new FileInputStream(fileDescriptor.getFileDescriptor());
    FileChannel fileChannel = inputStream.getChannel();
    long startOffset = fileDescriptor.getStartOffset();
    long declaredLength = fileDescriptor.getDeclaredLength();
    return fileChannel.map(FileChannel.MapMode.READ_ONLY, startOffset, declaredLength);
}
 

@Override
public long open(DataSpec dataSpec) throws ContentDataSourceException {
  try {
    Uri uri = dataSpec.uri;
    this.uri = uri;

    transferInitializing(dataSpec);
    AssetFileDescriptor assetFileDescriptor = resolver.openAssetFileDescriptor(uri, "r");
    this.assetFileDescriptor = assetFileDescriptor;
    if (assetFileDescriptor == null) {
      throw new FileNotFoundException("Could not open file descriptor for: " + uri);
    }
    FileInputStream inputStream = new FileInputStream(assetFileDescriptor.getFileDescriptor());
    this.inputStream = inputStream;

    long assetStartOffset = assetFileDescriptor.getStartOffset();
    long skipped = inputStream.skip(assetStartOffset + dataSpec.position) - assetStartOffset;
    if (skipped != dataSpec.position) {
      // We expect the skip to be satisfied in full. If it isn't then we're probably trying to
      // skip beyond the end of the data.
      throw new EOFException();
    }
    if (dataSpec.length != C.LENGTH_UNSET) {
      bytesRemaining = dataSpec.length;
    } else {
      long assetFileDescriptorLength = assetFileDescriptor.getLength();
      if (assetFileDescriptorLength == AssetFileDescriptor.UNKNOWN_LENGTH) {
        // The asset must extend to the end of the file. If FileInputStream.getChannel().size()
        // returns 0 then the remaining length cannot be determined.
        FileChannel channel = inputStream.getChannel();
        long channelSize = channel.size();
        bytesRemaining = channelSize == 0 ? C.LENGTH_UNSET : channelSize - channel.position();
      } else {
        bytesRemaining = assetFileDescriptorLength - skipped;
      }
    }
  } catch (IOException e) {
    throw new ContentDataSourceException(e);
  }

  opened = true;
  transferStarted(dataSpec);

  return bytesRemaining;
}
 

/**
 * Sets the data source as a content Uri. Call this method before the rest
 * of the methods in this class. This method may be time-consuming.
 * 
 * @param context
 *            the Context to use when resolving the Uri
 * @param uri
 *            the Content URI of the data you want to play
 * @throws IllegalArgumentException
 *             if the Uri is invalid
 * @throws SecurityException
 *             if the Uri cannot be used due to lack of permission.
 */
public void setDataSource(Context context, Uri uri)
		throws IllegalArgumentException, SecurityException {
	if (uri == null) {
		throw new IllegalArgumentException();
	}

	String scheme = uri.getScheme();
	if (scheme == null || scheme.equals("file")) { // 匹配文件
		setDataSource(uri.getPath());
		return;
	}

	AssetFileDescriptor fd = null;
	try {
		ContentResolver resolver = context.getContentResolver();
		try {
			fd = resolver.openAssetFileDescriptor(uri, "r");// 读取文件
		} catch (FileNotFoundException e) {
			throw new IllegalArgumentException();
		}
		if (fd == null) {
			throw new IllegalArgumentException();
		}
		FileDescriptor descriptor = fd.getFileDescriptor();
		if (!descriptor.valid()) {
			throw new IllegalArgumentException();
		}
		// Note: using getDeclaredLength so that our behavior is the same
		// as previous versions when the content provider is returning
		// a full file.
		if (fd.getDeclaredLength() < 0) {
			setDataSource(descriptor);
		} else {
			setDataSource(descriptor, fd.getStartOffset(),
					fd.getDeclaredLength());
		}
		return;
	} catch (SecurityException ex) { 
	} finally {
		try {
			if (fd != null) {
				fd.close();
			}
		} catch (IOException ioEx) {
		}
	}
	setDataSource(uri.toString());
}
 

/**
 * Loads the audio or video specified by mediaPath into the given
 * MediaPlayer.
 *
 * @param mediaPlayer the MediaPlayer
 * @param form the Form
 * @param mediaPath the path to the media
 */
public static void loadMediaPlayer(MediaPlayer mediaPlayer, Form form, String mediaPath)
    throws IOException {
  MediaSource mediaSource = determineMediaSource(form, mediaPath);
  switch (mediaSource) {
    case ASSET:
      AssetFileDescriptor afd = getAssetsIgnoreCaseAfd(form,mediaPath);
      try {
        FileDescriptor fd = afd.getFileDescriptor();
        long offset = afd.getStartOffset();
        long length = afd.getLength();
        mediaPlayer.setDataSource(fd, offset, length);
      } finally {
        afd.close();
      }
      return;


    case REPL_ASSET:
      form.assertPermission(Manifest.permission.READ_EXTERNAL_STORAGE);
      mediaPlayer.setDataSource(replAssetPath(mediaPath));
      return;

    case SDCARD:
      form.assertPermission(Manifest.permission.READ_EXTERNAL_STORAGE);
      mediaPlayer.setDataSource(mediaPath);
      return;

    case FILE_URL:
      if (isExternalFileUrl(mediaPath)) {
        form.assertPermission(Manifest.permission.READ_EXTERNAL_STORAGE);
      }
      mediaPlayer.setDataSource(fileUrlToFilePath(mediaPath));
      return;

    case URL:
      // This works both for streaming and non-streaming.
      // TODO(halabelson): Think about whether we could get improved
      // performance if we did buffering control.
      mediaPlayer.setDataSource(mediaPath);
      return;

    case CONTENT_URI:
      mediaPlayer.setDataSource(form, Uri.parse(mediaPath));
      return;

    case CONTACT_URI:
      throw new IOException("Unable to load audio or video for contact " + mediaPath + ".");
  }
  throw new IOException("Unable to load audio or video " + mediaPath + ".");
}