How to transfer file from Server to Android Mobile using Socket

Question

How to transfer file from Server to Android Mobile using Socket maintaining its format. It could be any file such as pdf, html, png, txt etc. I want to push this file from Server to Android Mobile but on the Mobile side while saving file I want to know the format of the file which came from the Server. So how it could be done?

private class ClientRxThread extends Thread {
        String dstAddress;
        int dstPort;

        ClientRxThread(String address, int port) {
            dstAddress = address;
            dstPort = port;
        }

        @Override
        public void run() {
            Socket socket = null;

            try {
                socket = new Socket(dstAddress, dstPort);
                String name = "test";
                File file = new File(
                        Environment.getExternalStorageDirectory(),
                        name);

                ObjectInputStream ois = new ObjectInputStream(socket.getInputStream());

                byte[] bytes;
                FileOutputStream fos = null;
                try {
                    bytes = (byte[])ois.readObject();
                    fos = new FileOutputStream(file);
                    fos.write(bytes);
                } catch (ClassNotFoundException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                } finally {
                    if(fos!=null){
                        fos.close();
                    }

                }

                socket.close();

                MainActivity.this.runOnUiThread(new Runnable() {

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

            } catch (IOException e) {

                e.printStackTrace();

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

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

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

This is the client Side I want to know how to get the file format of the file sent from Server

String name = "test";
                File file = new File(
                        Environment.getExternalStorageDirectory(),
                        name);

Want to know how to find file format of the file sent from SERVER. File from the Server could be html, png or txt FILE

Server Side relevant code

public class FileTxThread extends Thread {
        Socket socket;

        FileTxThread(Socket socket) {
            this.socket = socket;
        }

        @Override
        public void run() {
            File file = new File(
                    Environment.getExternalStorageDirectory(),
                    "test.png");

            byte[] bytes = new byte[(int) file.length()];
            BufferedInputStream bis;
            try {
                bis = new BufferedInputStream(new FileInputStream(file));
                bis.read(bytes, 0, bytes.length);

                ObjectOutputStream oos = new ObjectOutputStream(socket.getOutputStream());
                oos.writeObject(bytes);
                oos.flush();

                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();
                }
            }

        }
    }


File file = new File(
                        Environment.getExternalStorageDirectory(),
                        "test.png");

The test.png could have png, html, txt extension. So is there any way to send extension?

Answer 1

In server side send the filename too.

File file = new File(Environment.getExternalStorageDirectory(),
                    "test.png");

ObjectOutputStream oos = new ObjectOutputStream(socket.getOutputStream());
oos.writeObject(file.getName().getBytes());
oos.flush();

//then send the file

In Client side receive that name first and then read the file as second object

byte[] fileNameBytes = (byte[])ois.readObject();
String name = new String(fileNameBytes);

//read the second object as file

Answer 2

这可能会对您有所帮助， 请查看此GitHub页面