如何将资产读取到inputFileStream?

我的目标是将图像放在资产文件夹中,稍后将上载到Firebase存储。由于图像文件将与应用程序打包,我需要使用Firebase的putStream方法上载文件。但是,我无法将图像文件读入流。

我所尝试的:

public static InputStream readAssetsFileToStream(String fileName, Context context) {
    AssetManager assManager = context.getAssets();
    InputStream is = null;
    try {
        is = assManager.open(fileName);
    } catch (Exception e) {
        e.getMessage();
    } finally {
        try {
            if (is != null)
                is.close();
        } catch (Exception e2) {
            e2.getMessage();
        }
    }
    InputStream isOutput = new BufferedInputStream(is);
    return isOutput;
}

然后在需要上载文件的位置:

public  void uploadFile() throws IOException {

        Log.i("Firebase", "Upload started!");

       InputStream is = readAssetsFileToStream("abc", getApplicationContext());



        int size = is.available();
        byte[] buffer = new byte[size]; //declare the size of the byte array with size of the file
        is.read(buffer); //read file
        is.close(); //close file

        String streamData = new String(buffer);
     //   Uri file = Uri.fromFile(new File("path/to/raw/book.pdf"));sourc

      //  StorageReference riversRef = mStorageRef.child("/quadcopter.pdf");


        mStorageRef.putStream(is)
                .addOnSuccessListener(new OnSuccessListener<UploadTask.TaskSnapshot>() {
                    @Override
                    public void onSuccess(UploadTask.TaskSnapshot taskSnapshot) {
                        // Get a URL to the uploaded content
                        Uri downloadUrl = taskSnapshot.getDownloadUrl();
                        Log.i("Firebase", downloadUrl.toString());
                        Log.i("Firebase", "Upload Successful!");
                    }


                })
                .addOnFailureListener(new OnFailureListener() {
                    @Override
                    public void onFailure(@NonNull Exception exception) {
                        Log.i("Firebase", "Upload failed");
                        Log.i("Firebase", exception.getMessage());
                        // ...
                    }
                }).addOnCompleteListener(new OnCompleteListener<UploadTask.TaskSnapshot>() {
            @Override
            public void onComplete(@NonNull Task<UploadTask.TaskSnapshot> task) {
                Log.i("Firebase", "Upload Complete!");

            }
        }).addOnProgressListener(new OnProgressListener<UploadTask.TaskSnapshot>() {
            @Override
            public void onProgress(UploadTask.TaskSnapshot taskSnapshot) {
                Log.i("Firebase", String.valueOf(taskSnapshot.getBytesTransferred()));
            }
        });
    }

上载文件时,我在以下位置收到错误:

    int size = is.available();

也就是说,

java.io.IOException: BufferedInputStream is closed

我的项目结构:

我需要上传“abc”。jpg文件。非常感谢您的帮助。