我只是想知道是否可以通过蓝牙同时连接多个设备。我的意思是一个设备想要在同一时间与其他两个设备共享一些信息是否可以通过蓝牙？ （我有2个Nexus 5，一个Nexus 7）。
这是我的发起人：
if(requestCode == REQUEST_CONNECT_DEVICE){
// When DeviceListActivity returns with a device to connect
if (resultCode == Activity.RESULT_OK) {
// Get the device MAC address
ArrayList<String> address = data.getExtras().getStringArrayList(DeviceListActivity.EXTRA_DEVICE_ADDRESS);
// Get the BLuetoothDevice object
BluetoothDevice device = mBluetoothAdapter.getRemoteDevice(address.get(0));
BluetoothDevice device2 = mBluetoothAdapter.getRemoteDevice(address.get(1));
ArrayList<BluetoothDevice> devices=new ArrayList<BluetoothDevice>();
devices.add(device);
devices.add(device2);
// Attempt to connect to the device
mChatService.connect(devices);
}
}
}
这是我的蓝牙聊天服务：
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.UUID;
import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;
import android.bluetooth.BluetoothServerSocket;
import android.bluetooth.BluetoothSocket;
import android.content.Context;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.util.Log;
public class BluetoothChatService {
// Debugging
private static final String TAG = "BluetoothChatService";
private static final boolean D = true;
// Name for the SDP record when creating server socket
private static final String NAME = "BluetoothChatMulti";
// Member fields
private final BluetoothAdapter mAdapter;
private final Handler mHandler;
private AcceptThread mAcceptThread;
private ConnectThread mConnectThread;
private ConnectedThread mConnectedThread;
private int mState;
private ArrayList<String> mDeviceAddresses;
private ArrayList<ConnectedThread> mConnThreads;
private ArrayList<BluetoothSocket> mSockets;
private boolean bothConnected=false;
/**
* A bluetooth piconet can support up to 7 connections. This array holds 7 unique UUIDs.
* When attempting to make a connection, the UUID on the client must match one that the server
* is listening for. When accepting incoming connections server listens for all 7 UUIDs.
* When trying to form an outgoing connection, the client tries each UUID one at a time.
*/
private ArrayList<UUID> mUuids;
// 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 context The UI Activity Context
* @param handler A Handler to send messages back to the UI Activity
*/
public BluetoothChatService(Context context, Handler handler) {
mAdapter = BluetoothAdapter.getDefaultAdapter();
mState = STATE_NONE;
mHandler = handler;
mDeviceAddresses = new ArrayList<String>();
mConnThreads = new ArrayList<ConnectedThread>();
mSockets = new ArrayList<BluetoothSocket>();
mUuids = new ArrayList<UUID>();
// 7 randomly-generated UUIDs. These must match on both server and client.
mUuids.add(UUID.fromString("b7746a40-c758-4868-aa19-7ac6b3475dfc"));
mUuids.add(UUID.fromString("2d64189d-5a2c-4511-a074-77f199fd0834"));
}
/**
* Set the current state of the chat connection
* @param state An integer defining the current connection state
*/
private synchronized void setState(int state) {
if (D) Log.d(TAG, "setState() " + mState + " -> " + state);
mState = state;
// Give the new state to the Handler so the UI Activity can update
mHandler.obtainMessage(InitiatorActivity.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() {
if (D) Log.d(TAG, "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(ArrayList<BluetoothDevice> devices) {
// 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;}
*/
// Create a new thread and attempt to connect to each UUID one-by-one.
for (int i = 0; i < 2; i++) {
try {
mConnectThread = new ConnectThread(devices.get(i), mUuids.get(i));
mConnectThread.start();
} catch (Exception e) {
}
}
}
/**
* 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) {
if (D) Log.d(TAG, "connected");
//Commented out all the cancellations of existing threads, since we want multiple connections.
/*
// 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();
// Add each connected thread to an array
mConnThreads.add(mConnectedThread);
// Send the name of the connected device back to the UI Activity
Message msg = mHandler.obtainMessage(InitiatorActivity.MESSAGE_DEVICE_NAME);
Bundle bundle = new Bundle();
bundle.putString(InitiatorActivity.DEVICE_NAME, device.getName());
msg.setData(bundle);
mHandler.sendMessage(msg);
setState(STATE_CONNECTED);
}
/**
* Stop all threads
*/
public synchronized void stop() {
if (D) Log.d(TAG, "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) {
// When writing, try to write out to all connected threads
for (int i = 0; i < mConnThreads.size(); i++) {
try {
// Create temporary object
ConnectedThread r;
// Synchronize a copy of the ConnectedThread
synchronized (this) {
if (mState != STATE_CONNECTED) return;
r = mConnThreads.get(i);
}
// Perform the write unsynchronized
r.write(out);
} catch (Exception e) {
}
}
}
/**
* Indicate that the connection attempt failed and notify the UI Activity.
*/
private void connectionFailed() {
setState(STATE_LISTEN);
// Commented out, because when trying to connect to all 7 UUIDs, failures will occur
// for each that was tried and unsuccessful, resulting in multiple failure toasts.
// Send a failure message back to the Activity
Message msg = mHandler.obtainMessage(InitiatorActivity.MESSAGE_TOAST);
Bundle bundle = new Bundle();
bundle.putString(InitiatorActivity.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(InitiatorActivity.MESSAGE_TOAST);
Bundle bundle = new Bundle();
bundle.putString(InitiatorActivity.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 {
BluetoothServerSocket serverSocket = null;
public AcceptThread() {
}
public void run() {
if (D) Log.d(TAG, "BEGIN mAcceptThread" + this);
setName("AcceptThread");
BluetoothSocket socket = null;
try {
// Listen for all 7 UUIDs
for (int i = 0; i < 2; i++) {
serverSocket = mAdapter.listenUsingRfcommWithServiceRecord(NAME, mUuids.get(i));
socket = serverSocket.accept();
if (socket != null) {
String address = socket.getRemoteDevice().getAddress();
mSockets.add(socket);
mDeviceAddresses.add(address);
connected(socket, socket.getRemoteDevice());
}
}
} catch (IOException e) {
Log.e(TAG, "accept() failed", e);
}
if (D) Log.i(TAG, "END mAcceptThread");
}
public void cancel() {
if (D) Log.d(TAG, "cancel " + this);
try {
serverSocket.close();
} catch (IOException e) {
Log.e(TAG, "close() of server failed", 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;
private UUID tempUuid;
public ConnectThread(BluetoothDevice device, UUID uuidToTry) {
mmDevice = device;
BluetoothSocket tmp = null;
tempUuid = uuidToTry;
// Get a BluetoothSocket for a connection with the
// given BluetoothDevice
try {
Method m = device.getClass().getMethod("createRfcommSocket", new Class[] {int.class});
tmp = (BluetoothSocket) m.invoke(device, 1);
} catch (NoSuchMethodException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IllegalAccessException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IllegalArgumentException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (InvocationTargetException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
mmSocket = tmp;
}
public void run() {
Log.i(TAG, "BEGIN mConnectThread");
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) {
if (tempUuid.toString().contentEquals(mUuids.get(1).toString())) {
connectionFailed();
}
// Close the socket
try {
mmSocket.close();
} catch (IOException e2) {
Log.e(TAG, "unable to close() socket during connection failure", e2);
}
// Start the service over to restart listening mode
BluetoothChatService.this.start();
return;
}
// Reset the ConnectThread because we're done
synchronized (BluetoothChatService.this) {
mConnectThread = null;
}
// Start the connected thread
connected(mmSocket, mmDevice);
}
public void cancel() {
try {
mmSocket.close();
} catch (IOException e) {
Log.e(TAG, "close() of connect socket failed", 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) {
Log.d(TAG, "create ConnectedThread");
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) {
Log.e(TAG, "temp sockets not created", e);
}
mmInStream = tmpIn;
mmOutStream = tmpOut;
}
public void run() {
Log.i(TAG, "BEGIN mConnectedThread");
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(InitiatorActivity.MESSAGE_READ, bytes, -1, buffer)
.sendToTarget();
} catch (IOException e) {
Log.e(TAG, "disconnected", 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(InitiatorActivity.MESSAGE_WRITE, -1, -1, buffer)
.sendToTarget();
} catch (IOException e) {
Log.e(TAG, "Exception during write", e);
}
}
public void cancel() {
try {
mmSocket.close();
} catch (IOException e) {
Log.e(TAG, "close() of connect socket failed", e);
}
}
}
}
答案 0 :(得分：0)
Android上的蓝牙允许同时连接多个设备。限制与蓝牙无线电信道和所使用的任何更高级协议（例如RFCOMM）有关。在我的SmartGear应用程序中，我同时连接了2个蓝牙游戏控制器（RFCOMM）并且工作正常。
答案 1 :(得分：0)
蓝牙一次不能支持多个连接。在android中有点对点连接。如果你想将相同的数据发送到多个设备。从蓝牙样本中解决这个问题：
1.从集合或数组中的DevicelistActivity存储中获取所有最近的设备mac地址。
2.借助设备的mac地址逐个连接设备。
3.连接一台设备并完成数据发送后，终止上一次连接并建立新连接并连接另一台设备。
4.希望这些信息对你有帮助。