java - Android无法显示部分通过socket传输的图像

Question

我的应用程序向局域网中的其他设备发送一些文本和图像。看起来图像传输和接收成功(我根本没有遇到任何异常)，但不知何故，某些图像在 CardViewAdapter 的 imageView 中显示不佳或根本不显示。

当我收到图像时，我创建文件并使用 createFile 方法保存它。我还传输图像类型并使用此扩展名保存它。我不知道它取决于什么，但我无法解决它。

通过 tcp 发送图像的类:

    public class ImageTransferHandler implements Runnable{
        private static final String TAG = "ImageTransferHandler";
        private static final int SERVER_PORT = 8700;
        private Socket socket;
        private Context context;
        private String hostIpAddress;
        private Bar bar;

        public ClientThreadProcessor(String hostIpAddress, Context context, Bar bar){
            this.context = context;
            this.hostIpAddress = hostIpAddress;
            this.Bar = bar;
        }

        private Socket getSocket(String hostIpAddress) {
                InetAddress serverAddr = InetAddress.getByName(hostIpAddress);
                socket = new Socket(serverAddr, SERVER_PORT);
            return socket;
        }

        private void closeSocket(Socket socket) {
                    socket.close();
        }

        @Override
        public void run() {

            socket = getSocket(hostIpAddress);

            OutputStream outputStream = socket.getOutputStream();


            PrintWriter output = new PrintWriter(new BufferedWriter(
                                            new OutputStreamWriter(outputStream)), true);

            output.println(bar.getImageInfo().isCamera());
            Uri imageUri = Uri.parse(bar.getImageInfo().getPath());
            String mimeType = ImagePicker.getMimeType(context, imageUri);
            String ext = mimeType.substring(mimeType.lastIndexOf("/") + 1);
            if(ext == null) ext = "bmp";
            output.println(ext);
            BufferedOutputStream bout = new BufferedOutputStream(outputStream);
            String realPath = ImagePicker.getRealPathFromUri(context, imageUri);

            InputStream input = new FileInputStream(realPath);

            byte[] buffer = new byte[1024];
            int len;
            while ((len = input.read(buffer)) != -1) {
                bout.write(buffer);
            }
            input.close();
            bout.close();
            Log.d(TAG, "Image sent over network and stream is closed.");                                        

            output.close();

            closeSocket(socket);

        }

    }

通过 tcp 接收图像的类

public class ImageReceiveHandler implements Runnable{
        private static String TAG = "ImageReceiveHandler";
        private Socket socket;
        private Context context;
        private BufferedReader inputBufferedReader;
        private PrintWriter outputPrintWriter;
        private Bar Bar;


        public ClientHandler(Socket socket, Context context){
            this.socket = socket;
            this.context = context;
        }

        @Override
        public void run() {

                InputStream input = socket.getInputStream();
                inputBufferedReader = new BufferedReader(
                                        new InputStreamReader(input));

                outputPrintWriter = new PrintWriter(new BufferedWriter(
                        new OutputStreamWriter(socket.getOutputStream())), true);

                boolean isCamera = Boolean.valueOf(inputBufferedReader.readLine());
                String ext = inputBufferedReader.readLine();

                File imageFile = ImagePicker.createFile(context, ImagePicker.isExternalStorageWritable(), ext);

                if (imageFile != null) {
                    Uri imageUri = Uri.fromFile(imageFile);
                    Log.d(TAG, "imageUri for received image: " + imageUri.toString());

                    BufferedInputStream bufin = null;
                    FileOutputStream output = null;

                    bufin = new BufferedInputStream(input);
                    output = new FileOutputStream(imageFile);

                    byte[] buffer = new byte[1024];
                    int len;
                    while((len = bufin.read(buffer)) != -1){
                       output.write(buffer);
                       output.flush();
                    }

                    output.close();
                    bufin.close();

                    Log.d(TAG, "Image is received and saved. File length: " + imageFile.length());

                    ImageInfo info = new ImageInfo(imageUri.toString(), isCamera);
                    Bar = new Bar(info);

                    addNotification(Bar, hostAddress);
                }
                else
                    Log.d(TAG, "ImagePicker.createFile returns NULL");


                inputBufferedReader.close();
                outputPrintWriter.close();
        }


        public File createFile(Context context, boolean external, String ext) {
            File direct;

            if(external)
                direct = new File(Environment.getExternalStorageDirectory() + "/myo_images");
            else
                direct = new File(context.getFilesDir() + "/myo_images");


            if (!direct.exists()) {
                File imagesDir;
                if(external)
                    imagesDir = new File("/sdcard/myo_images/");
                else
                    imagesDir = new File("/myo_images");

                imagesDir.mkdirs();
            }

            String timestamp =  new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date());

            File file = null;

            if(external) 
                 file = File.createTempFile("myo_" + timestamp, "." + ext, direct);
            else 
                 file = File.createTempFile("myo_" + timestamp, "." + ext, direct);

            return file;
        }
    }

应可视化图像的适配器类

public class BarsCardViewAdapter extends RecyclerView.Adapter<BarsCardViewAdapter.CardViewHolder> {

        private List<BarData> activeBars;
        private final static String TAG = "CARDVIEW_ADAPTER";


        public BarsCardViewAdapter(List<BarData> Bars){
            activeBars = Bars;
        }

        public static class CardViewHolder extends RecyclerView.ViewHolder {
            private ActiveBarsListItemBinding listItemBinding;

            public CardViewHolder(View v) {
                super(v);
                listItemBinding = DataBindingUtil.bind(v);
            }

            public ActiveBarsListItemBinding getBinding(){
                return listItemBinding;
            }

        }

        @Override
        public BarsCardViewAdapter.CardViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
            View v = LayoutInflater.from(parent.getContext())
                    .inflate(R.layout.bars_list_item, parent, false);

            CardViewHolder holder = new CardViewHolder(v);
            return holder;
        }



        @Override
        public void onBindViewHolder(final BarsCardViewAdapter.CardViewHolder holder, final int position) {
            holder.getBinding().imageView.setVisibility(View.GONE);
            final Bar bar  = activeBars.get(position);
            final ImageInfo imageInfo = bar.getImageInfo();
            final LinearLayout rLayout = holder.getBinding().listItemLayout;


            ImageInfo imageInfo = BarData.getImageInfo();
            Log.d(TAG, "imagePath: " + Uri.parse(imageInfo.getPath()));
            holder.getBinding().imageView.setVisibility(View.VISIBLE);
            Picasso.with(rLayout.getContext()).
                        load(imageInfo.getPath()).
                        transform(new CropSquareTransformation()).
                        into(holder.getBinding().imageView);


            holder.getBinding().setVariable(BR.Bar, bar);
            holder.getBinding().executePendingBindings();
        }

        @Override
        public int getItemCount() {
            return activeBars.size();
        }



    }

Answer 1

您正在尝试读取二进制数据，但使用的读取器根据指定的字符集使用某种转换将字节转换为字符:

inputBufferedReader = new BufferedReader(
                          new InputStreamReader(input));

这将打开使用系统字符集的阅读器(例如 UTF8 或 cp1252)

不要使用 Reader 和 Writer，而是使用流，在本例中是 BufferedInputStream 和 BufferedOutputStream 以及读/写字节 block 。