蓝牙连接服务连接线程

Question

I have a Bluetooth service in my project and i connect all fragment but i cant send message with Connected Thread. it does not work correctly. Where is my false ? I am looking for solution since 3 days I can not find any solution. Why i cant send any message. My log return:

BluetoothConnectionService.write(byte[])' on a null object reference

i know ConnectedThread empty but why it is empty ?

public ConnectedThread(BluetoothSocket socket) {
        Log.d(TAG, "ConnectedThread: Starting.");

        mmSocket = socket;
        InputStream tmpIn = null;
        OutputStream tmpOut = null;
      //  ObjectInputStream tmpObjIn = null;
        //ObjectOutputStream tmpObjOut = null;
        if(socket!=null)
        {
            Log.d(TAG, "ConnectedThread: Socket not empty");

        }

        //dismiss the progressdialog when connection is established
        try{
            mProgressDialog.dismiss();
        }catch (NullPointerException e){
            e.printStackTrace();
        }


        try {
            tmpIn = mmSocket.getInputStream();
            tmpOut = mmSocket.getOutputStream();
            //tmpObjOut = new ObjectOutputStream(tmpOut);
            //tmpObjOut.flush();
            //tmpObjIn = new ObjectInputStream(tmpIn);
        } catch (IOException e) {
            Log.d(TAG, "ConnectedThread: doest work OUTPUT");

            e.printStackTrace();
        }

        mmInStream = tmpIn;
        mmOutStream = tmpOut;
      //  mObjectOutStream = tmpObjOut;
       // mObjectInStream = tmpObjIn;

    }

This is all service.java code:

    package com.example.duygu.mybluetoothdevicelist;

import android.app.ProgressDialog;
import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;
import android.bluetooth.BluetoothServerSocket;
import android.bluetooth.BluetoothSocket;
import android.content.Context;
import android.content.Intent;
import android.support.v4.content.LocalBroadcastManager;
import android.util.Log;

import java.io.IOException;
import java.io.InputStream;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.OutputStream;
import java.net.Socket;
import java.nio.charset.Charset;
import java.util.UUID;


public class BluetoothConnectionService {
    private static final String TAG = "BluetoothConnectionServ";

    private static final String appName = "MYAPP";

    private static final UUID MY_UUID_INSECURE =
            UUID.fromString("8ce255c0-200a-11e0-ac64-0800200c9a66");

    private final BluetoothAdapter mBluetoothAdapter;
    Context mContext;

    private AcceptThread mInsecureAcceptThread;

    private ConnectThread mConnectThread;
    private BluetoothDevice mmDevice;
    private UUID deviceUUID;
    ProgressDialog mProgressDialog;
    private BluetoothSocket mmSocket;
    private ConnectedThread mConnectedThread;

    public BluetoothConnectionService(Context context) {
        mContext = context;
        mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
        start();
    }


    /**
     * This thread runs while listening for incoming connections. It behaves
     * like a server-side client. It runs until a connection is accepted
     * (or until cancelled).
     */
    private class AcceptThread extends Thread {

        // The local server socket
        private final BluetoothServerSocket mmServerSocket;

        public AcceptThread(){
            BluetoothServerSocket tmp = null;

            // Create a new listening server socket
            try{
                tmp = mBluetoothAdapter.listenUsingInsecureRfcommWithServiceRecord(appName, MY_UUID_INSECURE);

                Log.d(TAG, "AcceptThread: Setting up Server using: " + MY_UUID_INSECURE);
            }catch (IOException e){
                Log.e(TAG, "AcceptThread: IOException: " + e.getMessage() );
            }

            mmServerSocket = tmp;
        }

        public void run(){
            Log.d(TAG, "run: AcceptThread Running.");

            BluetoothSocket socket = null;

            try{
                // This is a blocking call and will only return on a
                // successful connection or an exception
                Log.d(TAG, "run: RFCOM server socket start.....");

                socket = mmServerSocket.accept();

                Log.d(TAG, "run: RFCOM server socket accepted connection.");

            }catch (IOException e){
                Log.e(TAG, "AcceptThread: IOException: " + e.getMessage() );
            }

            //talk about this is in the 3rd
            if(socket != null){
                connected(socket,mmDevice);
            }

            Log.i(TAG, "END mAcceptThread ");
        }

        public void cancel() {
            Log.d(TAG, "cancel: Canceling AcceptThread.");
            try {
                mmServerSocket.close();
            } catch (IOException e) {
                Log.e(TAG, "cancel: Close of AcceptThread ServerSocket failed. " + e.getMessage() );
            }
        }

    }

    /**
     * This thread runs while attempting to make an outgoing connection
     * with a device. It runs straight through; the connection either
     * succeeds or fails.
     */
    private class ConnectThread extends Thread {


        public ConnectThread(BluetoothDevice device, UUID uuid) {
            Log.d(TAG, "ConnectThread: started.");
            mmDevice = device;
            deviceUUID = uuid;
        }

        public void run(){
            BluetoothSocket tmp = null;
            Log.i(TAG, "RUN mConnectThread ");

            // Get a BluetoothSocket for a connection with the
            // given BluetoothDevice
            try {
                Log.d(TAG, "ConnectThread: Trying to create InsecureRfcommSocket using UUID: "
                        +MY_UUID_INSECURE );
                tmp = mmDevice.createRfcommSocketToServiceRecord(deviceUUID);
            } catch (IOException e) {
                Log.e(TAG, "ConnectThread: Could not create InsecureRfcommSocket " + e.getMessage());
            }

            mmSocket = tmp;

            // Always cancel discovery because it will slow down a connection
            mBluetoothAdapter.cancelDiscovery();

            // Make a connection to the BluetoothSocket

            try {
                // This is a blocking call and will only return on a
                // successful connection or an exception
                mmSocket.connect();

                Log.d(TAG, "run: ConnectThread connected.");
            } catch (IOException e) {
                // Close the socket
                try {
                    mmSocket.close();
                    Log.d(TAG, "run: Closed Socket.");
                } catch (IOException e1) {
                    Log.e(TAG, "mConnectThread: run: Unable to close connection in socket " + e1.getMessage());
                }
                Log.d(TAG, "run: ConnectThread: Could not connect to UUID: " + MY_UUID_INSECURE );
            }

            //will talk about this in the 3rd video
            connected(mmSocket,mmDevice);
        }
        public void cancel() {
            try {
                Log.d(TAG, "cancel: Closing Client Socket.");
                mmSocket.close();
            } catch (IOException e) {
                Log.e(TAG, "cancel: close() of mmSocket in Connectthread failed. " + e.getMessage());
            }
        }
    }



    /**
     * Start the chat service. Specifically start AcceptThread to begin a
     * session in listening (server) mode. Called by the Activity onResume()
     */
    public synchronized void start() {
        Log.d(TAG, "start");

        // Cancel any thread attempting to make a connection
        if (mConnectThread != null) {
            mConnectThread.cancel();
            mConnectThread = null;
        }
        if (mInsecureAcceptThread == null) {
            mInsecureAcceptThread = new AcceptThread();
            mInsecureAcceptThread.start();
        }
    }

    /**
     AcceptThread starts and sits waiting for a connection.
     Then ConnectThread starts and attempts to make a connection with the other devices AcceptThread.
     **/

    public void startClient(BluetoothDevice device,UUID uuid){
        Log.d(TAG, "startClient: Started.");

        //initprogress dialog
        mProgressDialog = ProgressDialog.show(mContext,"Connecting Bluetooth"
                ,"Please Wait...",true);

        mConnectThread = new ConnectThread(device, uuid);
        mConnectThread.start();
    }

    /**
     Finally the ConnectedThread which is responsible for maintaining the BTConnection, Sending the data, and
     receiving incoming data through input/output streams respectively.
     **/
    private class ConnectedThread extends Thread {
        private final BluetoothSocket mmSocket;
        private final InputStream mmInStream;
        private final OutputStream mmOutStream;
        //private final ObjectInputStream mObjectInStream;
      //  private final ObjectOutputStream mObjectOutStream;

        public ConnectedThread(BluetoothSocket socket) {
            Log.d(TAG, "ConnectedThread: Starting.");

            mmSocket = socket;
            InputStream tmpIn = null;
            OutputStream tmpOut = null;
          //  ObjectInputStream tmpObjIn = null;
            //ObjectOutputStream tmpObjOut = null;
            if(socket!=null)
            {
                Log.d(TAG, "ConnectedThread: Socket not empty");

            }

            //dismiss the progressdialog when connection is established
            try{
                mProgressDialog.dismiss();
            }catch (NullPointerException e){
                e.printStackTrace();
            }


            try {
                tmpIn = mmSocket.getInputStream();
                tmpOut = mmSocket.getOutputStream();
                //tmpObjOut = new ObjectOutputStream(tmpOut);
                //tmpObjOut.flush();
                //tmpObjIn = new ObjectInputStream(tmpIn);
            } catch (IOException e) {
                Log.d(TAG, "ConnectedThread: doest work OUTPUT");

                e.printStackTrace();
            }

            mmInStream = tmpIn;
            mmOutStream = tmpOut;
          //  mObjectOutStream = tmpObjOut;
           // mObjectInStream = tmpObjIn;

        }

        public void run(){
            byte[] buffer = new byte[1024];  // buffer store for the stream

            int bytes; // bytes returned from read()

            // Keep listening to the InputStream until an exception occurs
            while (true) {
                // Read from the InputStream
                try {
                    bytes = mmInStream.read(buffer);
                    String incomingMessage = new String(buffer, 0, bytes);
                    Log.d(TAG, "InputStream: " + incomingMessage);
                    Intent incomingMessageIntent = new Intent("incomingMessage");

                    incomingMessageIntent.putExtra("theMessage", incomingMessage);
                    LocalBroadcastManager.getInstance(mContext).sendBroadcast(incomingMessageIntent);

                } catch (IOException e) {
                    Log.e(TAG, "write: Error reading Input Stream. " + e.getMessage() );
                    break;
                }
            }
        }







        //Call this from the main activity to send data to the remote device
        public void write(byte[] bytes) {


            String text = new String(bytes, Charset.defaultCharset());
            Log.d(TAG, "write: Writing to outputstream: " + text);
            try {



                mmOutStream.write(bytes);

            } catch (IOException e) {

                Log.e(TAG, "write: Error writing to output stream. " + e.getMessage() );
            }
        }

        /* Call this from the main activity to shutdown the connection */
        public void cancel() {
            try {
                mmSocket.close();
            } catch (IOException e) { }
        }
    }

    private void connected(BluetoothSocket mmSocket, BluetoothDevice mmDevice) {
        Log.d(TAG, "connected: Starting.");

        // Start the thread to manage the connection and perform transmissions
        mConnectedThread = new ConnectedThread(mmSocket);
        mConnectedThread.start();
    }

    /**
     * Write to the ConnectedThread in an unsynchronized manner
     *
     * @param out The bytes to write
     * @see ConnectedThread#write(byte[])
     */
    public void write(byte[] out)  { //changed this

        // Create temporary object
            ConnectedThread r;
            r=mConnectedThread;

            // Synchronize a copy of the ConnectedThread
            Log.d(TAG, "write: Write Called.");
            //perform the write
            r.write(out);



    }

}

Answer 1

I found the solution. If you use fragment, you can do just receive message but you can not send message. If you want to send message you have to use MainActivity.java If you want to getting value on the fragment you use this type:

*Creating method on MainActivty.java (That is send message with mBluetoothService.write(bytes) use the parameters)

*On the fragment side, you have to write method what you want to send. And you have to send method to MainActivity.java

I am working on the for 5 days and finally i found the solution.