Can't open file received from socket android java

Question

I am making an app with socket in which i want to share data from two devices in the same wifi. With my code i can share the file successfully between two devices with the exact size of the file and saves into the device storage with a specific name but when i try to open it fails to open in the file manager. I have tried this with mp4 file and apk files

Here is the sender's code

        @Override
        public void run() {
            //File file = new File(src);
            File file = new File(Environment.getExternalStorageDirectory() + "/c.mp4");

            byte[] bytes = new byte[(int) file.length()];
       
            BufferedInputStream bis;
            try {
                bis = new BufferedInputStream(new FileInputStream(file));
                DataInputStream dis = new DataInputStream(bis);
                OutputStream os = socket.getOutputStream();
                DataOutputStream dos = new DataOutputStream(os);
                dos.writeUTF("anything");
                dos.writeLong(bytes.length);
                int read;
                while ((read = dis.read(bytes)) != -1){
                    dos.write(bytes,0,read);
                }


                //os.write(bytes, 0, bytes.length);  //commented
                //os.flush();   //commented
                socket.close();

                final String sentMsg = "File sent to: " + socket.getInetAddress();
                MainActivity.this.runOnUiThread(new Runnable() {

                    @Override
                    public void run() {
                        Toast.makeText(MainActivity.this, sentMsg, Toast.LENGTH_LONG).show();
                    }});

            } catch (FileNotFoundException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            } finally {
                try {
                    socket.close();
                } catch (IOException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }

And here is the receiver



        @Override
        public void run() {
            Socket socket = null;
            int bytesRead;
            InputStream in; //changed
            int bufferSize=0;

            try {
                socket = new Socket(dstAddress, dstPort);

                bufferSize = socket.getReceiveBufferSize();
                in = socket.getInputStream();
                DataInputStream clientData = new DataInputStream(in);
                File file = new File(Environment.getExternalStorageDirectory(), "c.mp4");
                OutputStream output = new FileOutputStream(file);
                byte[] buffer = new byte[bufferSize];
                int read;
                while ((read = clientData.read(buffer)) != -1){
                    output.write(buffer, 0 , read);
                }


                //bos.close();  //commented
                socket.close();

                MainActivity2.this.runOnUiThread(new Runnable() {

                    @Override
                    public void run() {
                        Toast.makeText(MainActivity2.this, "Finished", Toast.LENGTH_LONG).show();
                    }});

            } catch (IOException e) {

                e.printStackTrace();

                final String eMsg = "Something wrong: " + e.getMessage();
                MainActivity2.this.runOnUiThread(new Runnable() {

                    @Override
                    public void run() {
                        Toast.makeText(MainActivity2.this,
                                eMsg,
                                Toast.LENGTH_LONG).show();
                    }});

            } finally {
                if(socket != null){
                    try {
                        socket.close();
                    } catch (IOException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                    }
                }
            }

ok i edited the description, and yes my app is sending and receiving file from one device to another — Divyansh Kumar, Aug 05 '20 at 09:01
Have you considered reading the `"anything"` and file length that you are sending? instead of letting them be written to the file? Or not sending them, if you aren't going to read them? — user207421, Aug 05 '20 at 10:00
yes this was the mistake and i already solved it thanks by the way — Divyansh Kumar, Aug 06 '20 at 05:46

naif.ult · Accepted Answer · 2020-08-05T07:24:31.703

0

You need to read the clientData (DataInputStream) in the same way you write it to the output stream of the socket.

uft-8 string, long value, seq. of bytes

Your mp4 file content will prefixed with "anything" and length. so it will be considered as corrupted file.

save the file without ("anything" and length)

edited Aug 05 '20 at 07:24

answered Aug 05 '20 at 07:16

naif.ult

186
6

thanks man it really worked – Divyansh Kumar Aug 05 '20 at 09:12

Can't open file received from socket android java

1 Answers1