How can i see how many bytes was received from GSON JsonReader

Question

While reading here and creating a large Object to send and receive using JsonWriter and JsonReader. I wanted to keep track of total bytes sent.

Answer 1

There's nothing in JsonWriter or JsonReader that is going to provide that for you.

Really the only way to do it would be to wrap/extend the Reader or Writer you're currently passing to JsonReader/JsonWriter and keep track of the bytes being read/written in/out.

Edit to add: As an example you could do something like:

class MyWriterWrapper extends Writer {

    private Writer realWriter;
    private int bytesWritten;

    public MyWriterWrapper(Writer realWriter) {
        super(); 
        this.realWriter = realWriter;
    }

    public int getBytesWritten() {
        return bytesWritten;
    }

    @Override
    public Writer append(CharSequence csq) throws IOException {
         realWriter.append(csq);
         bytesWritten += csq.length();
         return this;
    }

    // Implement/Override all other Writer methods the same way

}

It'd be a lot cleaner if Writer was an interface but ... meh, what can you do. If you know you're only ever going to use one type of Writer (say, a BufferedWriter) you could extend that, override all the methods and re-call the methods on this instead of the private realWriter instance passed in via the constructor.

Answer 2

There is not a default way to get number of received bytes from JsonReader. I have written a little tricky Hack which is mentioned bellow:

1. Read bytes from inputstream and write them to an internal-storage file

   while ((count = inputStream.read(data)) != -1)  {
                 total += count;
                 final long downloadedLength = total;
                 final long totalLength = lengthOfData;
              **// Here you get the size of bytes received**
                 outStream.write(data, 0, count);
             }
   

2. Close all the opened streams (input and output streams created above)

3. Open the inputstream of newly created file

   InputStream stream = mContext.openFileInput(FILE_NAME);
   InputStreamReader inputStreamReader = new InputStreamReader(stream);

4. Now you have an inputstream (stream) for JsonReader

5. Let JsonReader to use this inputstream for parsing data

6. After parsing completed, delete the file you created for temporary usage

   InputStream stream = mContext.openFileInput(FILE_NAME);
   InputStreamReader inputStreamReader = new InputStreamReader(stream);
   jsonReader = new JsonReader(inputStreamReader);
   parseMyJSON(jsonReader);

   File file = new File(mContext.getFilesDir(), FILE_NAME);
   file.delete();

Answer 3

No way. Even if you wrap your input stream in some kind of wrapper to count bytes (e. g. apache's CountingInputStream), the results will be incorrect because of JsonReader's internal buffering. I've experimented with ~300 bytes long JSONs. CountingInputStream reported that ~4kb was read each time.