写入和读取文件

Question

我在写入和读取文件时遇到问题。

代码如下：

@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
    super.onActivityResult(requestCode, resultCode, data);


    if (resultCode == Activity.RESULT_OK) {

        switch(requestCode) {
            case INTENT_COUNTRY:
                if (data.getExtras().containsKey("country")) {
                    final String c = data.getStringExtra("country");
                    Log.d("Profile", "Country: " + c);
                    txtCountry.setText(c);
                }
                break;

            case PICKER_CAMERA:
                Log.d("Profile", "PICKER_CAMERA");
                Bitmap bitmapCamera = (Bitmap) data.getExtras().get("data");
                Bitmap thumbnailCamera = ThumbnailUtils.extractThumbnail(bitmapCamera, 320, 320);

                ByteArrayOutputStream streamCamera = new ByteArrayOutputStream();
                thumbnailCamera.compress(Bitmap.CompressFormat.PNG, 100, streamCamera);
                byte[] byteArrayCamera = streamCamera.toByteArray();
                InputStream isCamera = new ByteArrayInputStream(byteArrayCamera);

                uploadPicture(isCamera);

                break;

            case PICKER_GALLERY:
                Log.d("Profile", "PICKER_GALLERY");
                Uri imageUri = data.getData();

                try {
                    Bitmap bitmapGallery = MediaStore.Images.Media.getBitmap(getActivity().getContentResolver(), imageUri);
                    Bitmap thumbnailGallery = ThumbnailUtils.extractThumbnail(bitmapGallery, 320, 320);

                    ByteArrayOutputStream streamGallery = new ByteArrayOutputStream();
                    thumbnailGallery.compress(Bitmap.CompressFormat.PNG, 100, streamGallery);
                    byte[] byteArrayGallery = streamGallery.toByteArray();
                    InputStream isGallery = new ByteArrayInputStream(byteArrayGallery);

                    uploadPicture(isGallery);

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

                break;

            default:
                Log.d("Profile", "Unmanaged request code: " + requestCode);
                break;
        }
    }
}

public void uploadPicture(InputStream is) {
    final ProgressDialog progress = new ProgressDialog(getActivity());
    progress.setIndeterminate(true);
    progress.setCancelable(false);
    progress.setProgressStyle(ProgressDialog.STYLE_SPINNER);
    progress.setTitle(getString(R.string.loading));
    progress.setMessage(getString(R.string.loading_msg));
    progress.show();

    /* Upload*/
    AppDelegate appDelegate = (AppDelegate) getActivity().getApplication();
    appDelegate.setPicture(is, new Callable<Void>() {
        @Override
        public Void call() throws Exception {
            Log.d("Profile", "Upload ok");
            progress.dismiss();
            return null;
        }
    }, new Callable<Void>() {
        @Override
        public Void call() throws Exception {
            Log.d("Profile", "Upload failed");
            progress.dismiss();
            return null;
        }
    });
}

public void setPictureFile(final InputStream is) {
    String filename = "pict.png";
    FileOutputStream outputStream;
    try {
        outputStream = openFileOutput(filename, Context.MODE_PRIVATE);
        outputStream.write(IOUtils.toByteArray(is));
        outputStream.close();
        Log.d("Profile", "File stored locally.");
    } catch (Exception e) {
        e.printStackTrace();
    }
}

public Bitmap getPictureFile() {
    String filename = "pict.png";
    FileInputStream inputStream;
    //String filePath = getFilesDir().getAbsolutePath() + "/" + filename;
    Bitmap bitmap = null;
    try {
        inputStream = openFileInput(filename);
        BufferedInputStream buf = new BufferedInputStream(inputStream);
        bitmap = BitmapFactory.decodeStream(buf);
        //Bitmap bitmap = BitmapFactory.decodeFile(filename);
        if (bitmap == null) {
            Log.d("Profile", "WARNING: bitmap == null");
        }

        if (inputStream != null) {
            inputStream.close();
        }
        if (buf != null) {
            buf.close();
        }
    } catch(FileNotFoundException e) {
        Log.d("Profile", "Picture FILE not found.");
        e.printStackTrace();
        return null;
    } catch (OutOfMemoryError e) {
        Log.d("Profile", "Out Of Memory");
    } catch(Exception e) {
        e.printStackTrace();
    }
    return bitmap;
}

在控制台中，我总是有：

WARNING: bitmap == null

setPictureFile方法中的InputStream不为空(上传到web服务的工作正常)，并且我在setPictureFile中没有得到任何异常。

另一方面，当我试图读取文件时，位图似乎是空的，没有异常正在上升！

我试图读取的文件大约是200-300 KB，所以它并不大，我没有耗尽内存。

有人知道这是怎么回事吗？

Answer 1

解决了。到处使用byte[]而不是InputStream解决了我的问题。

public void setPictureFile(final byte[] buffer) {
    String filename = "pict.png";
    FileOutputStream outputStream;

    try {
        outputStream = openFileOutput(filename, Context.MODE_PRIVATE);
        outputStream.write(buffer);
        outputStream.close();
        Log.d("Profile", "File stored locally.");
    } catch (Exception e) {
        Log.d("Profile", e.toString());
        e.printStackTrace();
    }
}

public Bitmap getPictureFile() {
    String filename = "pict.png";
    FileInputStream inputStream;

    // http://stackoverflow.com/questions/11182714/bitmapfactory-example
    // http://developer.android.com/guide/topics/data/data-storage.html#filesInternal

    //String filePath = getFilesDir().getAbsolutePath() + "/" + filename;

    Bitmap bitmap = null;

    try {
        inputStream = openFileInput(filename);
        byte[] reader = new byte[inputStream.available()];
        if (inputStream.read(reader)!=-1) {
            Log.d("Profile", "Reading from stream...");
        }
        Log.d("Profile", "Stream length: " + reader.length);
        bitmap = BitmapFactory.decodeByteArray(reader, 0, reader.length);
        //BufferedInputStream buf = new BufferedInputStream(inputStream);
        //bitmap = BitmapFactory.decodeStream(inputStream);

        //Bitmap bitmap = BitmapFactory.decodeFile(filename);

        if (bitmap == null) {
            Log.d("Profile", "WARNING: bitmap == null");
        }

        inputStream.close();

        //if (buf != null) {
        //    buf.close();
        //}
    } catch(FileNotFoundException e) {
        Log.d("Profile Exception", e.toString());
        e.printStackTrace();
    } catch (OutOfMemoryError e) {
        Log.d("Profile Exception", e.toString());
    } catch(Exception e) {
        Log.d("Profile Exception", e.toString());
        e.printStackTrace();
    }

    return bitmap;
}