Android中的蓝牙连接与两台设备
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【中文标题】Android中的蓝牙连接与两台设备【英文标题】：Bluetooth connection in Android with two devices 【发布时间】：2014-03-17 20:34:15 【问题描述】：我只是想知道是否可以通过蓝牙同时连接多个设备。我的意思是一台设备想同时与其他两台设备共享一些信息，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);
【问题讨论】：
【参考方案1】：Android 上的蓝牙允许一次连接多个设备。这些限制与蓝牙无线电频道和正在使用的任何更高级别的协议（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)，它工作正常。
【讨论】：
非常感谢您的回答。你能提供一个示例代码吗？我的应用程序不用于商业目的。它只是为了一项科学工作。 您需要 Android 中一般蓝牙连接的示例代码还是专门用于 2 连接案例的示例代码？就我而言，我连接了 0、1 或 2 个控制器，因此我为每个连接生成一个新线程，只要连接处于活动状态，它就会运行。我不确定您是否会从我的代码中受益，除非您有具体的疑问需要我提供帮助。 嗨，是的，我需要这样的东西。它是关于安全的多部分计算。我有一般的蓝牙连接，它工作得很好。我需要提供三个设备 A-B A-C B-C 之间的连接 如果您的连接已经正常工作，那么唯一缺少的就是线程。你需要使用：new Thread(new Runnable() public void run()蓝牙不能同时支持多个连接。在 android 中存在点对点连接。如果您想将相同的数据发送到多个设备。从蓝牙示例中解决此问题：
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.通过设备的mac地址，一一连接设备。
3.当连接一个设备并完成数据发送后，终止先前的连接并建立新的连接并连接另一台设备。
4.希望这些信息对你有所帮助。
【讨论】：
您好，谢谢您的回答：）我在夏天之前完成了它；）但我的解决方案是一样的；） @user12492 如果你对我的回答满意，请投票给我的回答。以上是关于Android中的蓝牙连接与两台设备的主要内容，如果未能解决你的问题，请参考以下文章