I'm working with Bluetooth in android.My main goal is to transmit large video file via Bluetooth. I'm following Bluetooth chat sample for connectivity. Actually i convert video into byte array and then in onRecieve method convert back to File. when converting back to file some exception occurs. I increased the buffer size in connected Thread.
To convert recieved byte[] into Hashmap<String, Byte[]>
private Object convertFromBytes(byte[] bytes) {
ByteArrayInputStream bis = new ByteArrayInputStream(bytes);
Object out = null;
ObjectInput in = null;
try {
in = new ObjectInputStream(bis);
out = in.readObject();
Log.d("bytetodata out", "");
} catch (IOException | ClassNotFoundException e) {
e.printStackTrace();
Log.d("bytetodata out", e.getLocalizedMessage());
} finally {
try {
if (in != null) {
in.close();
}
} catch (IOException ex) {
Log.e(TAG, ex.getLocalizedMessage());
// ignore close exception
}
}
Log.d("bytetodata out", "");
return out;
}
Exception occurs at
in = new ObjectInputStream(bis);
Bluetooth Reciever code
case MESSAGE_READ:
byte[] readBuf = (byte[]) msg.obj;
// construct a string from the valid bytes in the buffer
onRecieve(readBuf);
private void onRecieve(byte[] readBuf) {
HashMap<String, byte[]> receivedMap = (HashMap<String, byte[]>) convertFromBytes(readBuf);
//Log.d("recieveMAP Size" , String.valueOf(receivedMap.size()));
if (receivedMap != null && receivedMap.size() == 2) {
byte[] filebyte = receivedMap.get("file");
byte[] objectbyte = receivedMap.get("object");
if (filebyte != null) {
File file = new File("storage/emulated/0/Download/name.mp4");
try {
file.createNewFile();
} catch (IOException e) {
e.printStackTrace();
Log.e("Mainactivity", e.getLocalizedMessage());
}
if (file.exists()) {
try {
FileUtils.writeByteArrayToFile(file, filebyte);
} catch (IOException e) {
e.printStackTrace();
Log.e(TAG, e.getLocalizedMessage());
}
} else {
//System.out.println("file created: " + file);
Toast.makeText(context, "File is Empty", Toast.LENGTH_LONG).show();
}
} else {
Log.e(TAG, "selected video path = null!");
}
//System.out.println("file created: " + file);
//Toast.makeText(context, "File Created", Toast.LENGTH_LONG).show();
// Video video = (Video) convertFromBytes(objectbyte);
}
}
Bluetooth Connectivity code
private class ConnectedThread extends Thread {
private final BluetoothSocket mmSocket;
private final InputStream mmInStream;
private final OutputStream mmOutStream;
public ConnectedThread(BluetoothSocket socket) {
mmSocket = socket;
InputStream tmpIn = null;
OutputStream tmpOut = null;
// Get the BluetoothSocket input and output streams
try {
tmpIn = socket.getInputStream();
tmpOut = socket.getOutputStream();
} catch (IOException e) {
}
mmInStream = tmpIn;
mmOutStream = tmpOut;
}
public void run() {
byte[] buffer = new byte[ 4096 * 16 ];
int bytes;
// Keep listening to the InputStream while connected
while (true) {
try {
// Read from the InputStream
bytes = mmInStream.read(buffer);
// Send the obtained bytes to the UI Activity
mHandler.obtainMessage(BTListFragment.MESSAGE_READ, bytes, -1, buffer)
.sendToTarget();
} catch (IOException e) {
connectionLost();
break;
}
}
}
/**
* Write to the connected OutStream.
*
* @param buffer The bytes to write
*/
public void write(byte[] buffer) {
try {
mmOutStream.write(buffer);
// Share the sent message back to the UI Activity
mHandler.obtainMessage(BTListFragment.MESSAGE_WRITE, -1, -1, buffer)
.sendToTarget();
} catch (IOException e) {
}
}
public void cancel() {
try {
mmSocket.close();
} catch (IOException e) {
}
}
}
BlutoothConnectivityService.java
package com.example.accessagriculture.Utils;
import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;
import android.bluetooth.BluetoothServerSocket;
import android.bluetooth.BluetoothSocket;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import com.example.accessagriculture.Views.Fragments.BTListFragment;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.UUID;
/**
* This class does all the work for setting up and managing Bluetooth
* connections with other devices. It has a thread that listens for
* incoming connections, a thread for connecting with a device, and a
* thread for performing data transmissions when connected.
*/
public class BTConnectService {
// Name for the SDP record when creating server socket
private static final String NAME = "BluetoothChat";
// Unique UUID for this application
private static final UUID MY_UUID = UUID.fromString("fa87c0d0-afac-11de-8a39-0800200c9a66");
// Member fields
private final BluetoothAdapter mAdapter;
private final Handler mHandler;
private AcceptThread mAcceptThread;
private ConnectThread mConnectThread;
private ConnectedThread mConnectedThread;
private int mState;
// Constants that indicate the current connection state
public static final int STATE_NONE = 0; // we're doing nothing
public static final int STATE_LISTEN = 1; // now listening for incoming connections
public static final int STATE_CONNECTING = 2; // now initiating an outgoing connection
public static final int STATE_CONNECTED = 3; // now connected to a remote device
/**
* Constructor. Prepares a new BluetoothChat session.
* @param handler A Handler to send messages back to the UI Activity
*/
public BTConnectService(Handler handler) {
mAdapter = BluetoothAdapter.getDefaultAdapter();
mState = STATE_NONE;
mHandler = handler;
}
/**
* Set the current state of the chat connection
*
* @param state An integer defining the current connection state
*/
private synchronized void setState(int state) {
mState = state;
// Give the new state to the Handler so the UI Activity can update
mHandler.obtainMessage(BTListFragment.MESSAGE_STATE_CHANGE, state, -1).sendToTarget();
}
/**
* Return the current connection state.
*/
public synchronized int getState() {
return mState;
}
/**
* Start the chat service. Specifically start AcceptThread to begin a
* session in listening (server) mode. Called by the Activity onResume()
*/
public synchronized void start() {
// Cancel any thread attempting to make a connection
if (mConnectThread != null) {
mConnectThread.cancel();
mConnectThread = null;
}
// Cancel any thread currently running a connection
if (mConnectedThread != null) {
mConnectedThread.cancel();
mConnectedThread = null;
}
// Start the thread to listen on a BluetoothServerSocket
if (mAcceptThread == null) {
mAcceptThread = new AcceptThread();
mAcceptThread.start();
}
setState(STATE_LISTEN);
}
/**
* Start the ConnectThread to initiate a connection to a remote device.
*
* @param device The BluetoothDevice to connect
*/
public synchronized void connect(BluetoothDevice device) {
// Cancel any thread attempting to make a connection
if (mState == STATE_CONNECTING) {
if (mConnectThread != null) {
mConnectThread.cancel();
mConnectThread = null;
}
}
// Cancel any thread currently running a connection
if (mConnectedThread != null) {
mConnectedThread.cancel();
mConnectedThread = null;
}
// Start the thread to connect with the given device
mConnectThread = new ConnectThread(device);
mConnectThread.start();
setState(STATE_CONNECTING);
}
/**
* Start the ConnectedThread to begin managing a Bluetooth connection
*
* @param socket The BluetoothSocket on which the connection was made
* @param device The BluetoothDevice that has been connected
*/
public synchronized void connected(BluetoothSocket socket, BluetoothDevice device) {
// Cancel the thread that completed the connection
if (mConnectThread != null) {
mConnectThread.cancel();
mConnectThread = null;
}
// Cancel any thread currently running a connection
if (mConnectedThread != null) {
mConnectedThread.cancel();
mConnectedThread = null;
}
// Cancel the accept thread because we only want to connect to one device
if (mAcceptThread != null) {
mAcceptThread.cancel();
mAcceptThread = null;
}
// Start the thread to manage the connection and perform transmissions
mConnectedThread = new ConnectedThread(socket);
mConnectedThread.start();
// Send the name of the connected device back to the UI Activity
Message msg = mHandler.obtainMessage(BTListFragment.MESSAGE_DEVICE_NAME);
Bundle bundle = new Bundle();
bundle.putString(BTListFragment.DEVICE_NAME, device.getName());
msg.setData(bundle);
mHandler.sendMessage(msg);
setState(STATE_CONNECTED);
}
/**
* Stop all threads
*/
public synchronized void stop() {
if (mConnectThread != null) {
mConnectThread.cancel();
mConnectThread = null;
}
if (mConnectedThread != null) {
mConnectedThread.cancel();
mConnectedThread = null;
}
if (mAcceptThread != null) {
mAcceptThread.cancel();
mAcceptThread = null;
}
setState(STATE_NONE);
}
/**
* Write to the ConnectedThread in an unsynchronized manner
*
* @param out The bytes to write
* @see ConnectedThread#write(byte[])
*/
public void write(byte[] out) {
// Create temporary object
ConnectedThread r;
// Synchronize a copy of the ConnectedThread
synchronized (this) {
if (mState != STATE_CONNECTED) return;
r = mConnectedThread;
}
// Perform the write unsynchronized
r.write(out);
}
/**
* Indicate that the connection attempt failed and notify the UI Activity.
*/
private void connectionFailed() {
setState(STATE_LISTEN);
// Send a failure message back to the Activity
Message msg = mHandler.obtainMessage(BTListFragment.MESSAGE_TOAST);
Bundle bundle = new Bundle();
bundle.putString(BTListFragment.TOAST, "Unable to connect device");
msg.setData(bundle);
mHandler.sendMessage(msg);
}
/**
* Indicate that the connection was lost and notify the UI Activity.
*/
private void connectionLost() {
//setState(STATE_LISTEN);
// Send a failure message back to the Activity
/*Message msg = mHandler.obtainMessage(BTListFragment.MESSAGE_TOAST);
//Bundle bundle = new Bundle();
// bundle.putString(BTListFragment.TOAST, "Device connection was lost");
msg.setData(bundle);
mHandler.sendMessage(msg);*/
}
/**
* 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 = mAdapter.listenUsingRfcommWithServiceRecord(NAME, MY_UUID);
} catch (IOException e) {
}
mmServerSocket = tmp;
}
public void run() {
setName("AcceptThread");
BluetoothSocket socket = null;
// Listen to the server socket if we're not connected
while (mState != STATE_CONNECTED) {
try {
// This is a blocking call and will only return on a
// successful connection or an exception
socket = mmServerSocket.accept();
} catch (IOException e) {
break;
}
// If a connection was accepted
if (socket != null) {
synchronized (BTConnectService.this) {
switch (mState) {
case STATE_LISTEN:
case STATE_CONNECTING:
// Situation normal. Start the connected thread.
connected(socket, socket.getRemoteDevice());
break;
case STATE_NONE:
case STATE_CONNECTED:
// Either not ready or already connected. Terminate new socket.
try {
socket.close();
} catch (IOException e) {
}
break;
}
}
}
}
}
public void cancel() {
try {
mmServerSocket.close();
} catch (IOException e) {
}
}
}
/**
* 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 {
private final BluetoothSocket mmSocket;
private final BluetoothDevice mmDevice;
public ConnectThread(BluetoothDevice device) {
mmDevice = device;
BluetoothSocket tmp = null;
// Get a BluetoothSocket for a connection with the
// given BluetoothDevice
try {
tmp = device.createRfcommSocketToServiceRecord(MY_UUID);
} catch (IOException e) {
}
mmSocket = tmp;
}
public void run() {
setName("ConnectThread");
// Always cancel discovery because it will slow down a connection
mAdapter.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();
} catch (IOException e) {
connectionFailed();
// Close the socket
try {
mmSocket.close();
} catch (IOException e2) {
}
// Start the service over to restart listening mode
BTConnectService.this.start();
return;
}
// Reset the ConnectThread because we're done
synchronized (BTConnectService.this) {
mConnectThread = null;
}
// Start the connected thread
connected(mmSocket, mmDevice);
}
public void cancel() {
try {
mmSocket.close();
} catch (IOException e) {
}
}
}
/**
* This thread runs during a connection with a remote device.
* It handles all incoming and outgoing transmissions.
*/
private class ConnectedThread extends Thread {
private final BluetoothSocket mmSocket;
private final InputStream mmInStream;
private final OutputStream mmOutStream;
public ConnectedThread(BluetoothSocket socket) {
mmSocket = socket;
InputStream tmpIn = null;
OutputStream tmpOut = null;
// Get the BluetoothSocket input and output streams
try {
tmpIn = socket.getInputStream();
tmpOut = socket.getOutputStream();
} catch (IOException e) {
}
mmInStream = tmpIn;
mmOutStream = tmpOut;
}
public void run() {
byte[] buffer = new byte[1024];
int bytes;
// Keep listening to the InputStream while connected
while (true) {
try {
// Read from the InputStream
bytes = mmInStream.read(buffer);
// Send the obtained bytes to the UI Activity
mHandler.obtainMessage(BTListFragment.MESSAGE_READ, bytes, -1, buffer)
.sendToTarget();
} catch (IOException e) {
connectionLost();
break;
}
}
}
/**
* Write to the connected OutStream.
*
* @param buffer The bytes to write
*/
public void write(byte[] buffer) {
try {
mmOutStream.write(buffer);
// Share the sent message back to the UI Activity
mHandler.obtainMessage(BTListFragment.MESSAGE_WRITE, -1, -1, buffer)
.sendToTarget();
} catch (IOException e) {
}
}
public void cancel() {
try {
mmSocket.close();
} catch (IOException e) {
}
}
}
}
