我正在做一个 Android 应用程序，我需要 2 台或更多设备才能通过蓝牙连接到一台设备。以对等形式将两个设备连接在一起的代码有效，但是当我尝试连接另一个设备时，我收到一个 IOException 说“连接被拒绝”，因为 Socket 已关闭，因此无法完成配对。错误如下所示。
Socket closed. Unable to complete pairing.
java.io.IOException: Connection refused
at android.bluetooth.BluetoothSocket.connectNative(Native Method)
at android.bluetooth.BluetoothSocket.connect(BluetoothSocket.java:216)
at com.ablueworld.androidgridcomputingframework.BluetoothManager$ConnectAsyncTask.doInBackground(BluetoothManager.java:270)
at com.ablueworld.androidgridcomputingframework.BluetoothManager$ConnectAsyncTask.doInBackground(BluetoothManager.java:1)
at android.os.AsyncTask$2.call(AsyncTask.java:264)
at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:305)
at java.util.concurrent.FutureTask.run(FutureTask.java:137)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1076)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:569)
at java.lang.Thread.run(Thread.java:856)
Could not connect to this device
然后我读到它需要为每个连接有不同的 UUID，对吗？无论如何，我已经编写了如下所示的代码，为每个新连接从数组中获取不同的 UUID。
// Unique UUID for this application
private static int indexUUID = 0;
private static final UUID[] MY_UUID_SECURE = {UUID.fromString("98b97e6b-62ff-4a36-a81b-82256fd1d168"),
UUID.fromString("98b97e6b-62ff-4a36-a81b-82256fd1d169"),
UUID.fromString("98b97e6b-62ff-4a36-a81b-82256fd1d170"),
UUID.fromString("98b97e6b-62ff-4a36-a81b-82256fd1d171"),
UUID.fromString("98b97e6b-62ff-4a36-a81b-82256fd1d172")};
private static final String NAME_SECURE = "GridFrameworkSecure";
/**
* Method to connect securely to Bluetooth device using it's MAC address
* @param macAddress valid Bluetooth MAC address
*/
public boolean connectSecurelyToDevice(BluetoothAdapter btAdapter, String macAddress){
BluetoothDevice device = btAdapter.getRemoteDevice(macAddress);
ConnectAsyncTask connectTask = new ConnectAsyncTask();
BluetoothSocket deviceSocket = null;
try {
deviceSocket = connectTask.execute(device).get();
} catch (InterruptedException e) {
e.printStackTrace();
return false;
} catch (ExecutionException e) {
e.printStackTrace();
return false;
}
if(deviceSocket!=null){
if(serverBluetoothNode==null){
try {
serverBluetoothNode = new BluetoothNode(deviceSocket);
Log.i("bluetooth manager", "You are now a slave node.");
return true;
} catch (IOException e) {
e.printStackTrace();
return false;
}
} else {
Log.e("bluetooth manager", "You already have a master.");
return false;
}
} else return false;
}
/**
* Method to allow this Bluetooth device to accept connection from another Bluetooth device
*/
public void allowSecureConnectionFromRemoteDevice(BluetoothAdapter btAdapter){
AcceptConnectionAsyncTask acceptTask = new AcceptConnectionAsyncTask();
acceptTask.execute(btAdapter);
}
private class ConnectAsyncTask extends AsyncTask<BluetoothDevice, Void, BluetoothSocket> {
@Override
protected BluetoothSocket doInBackground(BluetoothDevice... params) {
BluetoothDevice device = params[0];
BluetoothSocket socket = null;
// Get a BluetoothSocket for a connection with the
// given BluetoothDevice
try {
socket = device.createRfcommSocketToServiceRecord(MY_UUID_SECURE[indexUUID]);
} catch (IOException e) {
Log.e("Bluetooth Pairing", "create() failed", e);
}
Log.i("Bluetooth Pairing", "BEGIN ConnectThread SocketType: Secure");
// Make a connection to the BluetoothSocket
try {
// This is a blocking call and will only return on a
// successful connection or an exception
socket.connect();
Log.i("bluetooth manager", "You have connected a slave node to this one.");
return socket;
} catch (IOException e) {
Log.e("Bluetooth Pairing", "Socket closed. Unable to complete pairing.", e);
// Close the socket
try {
socket.close();
indexUUID++;
} catch (IOException e2) {
Log.e("Bluetooth Pairing", "unable to close() socket during connection failure", e2);
}
}
return null;
}
}
private class AcceptConnectionAsyncTask extends AsyncTask<BluetoothAdapter, Void, Void> {
@Override
protected Void doInBackground(BluetoothAdapter... params) {
BluetoothServerSocket serverSocket = null;
String socketType = "Secure";
// Create a new listening server socket
try {
serverSocket = params[0].listenUsingRfcommWithServiceRecord(NAME_SECURE, MY_UUID_SECURE[indexUUID]);
} catch (IOException e) {
Log.e("Accept Bluetooth Pairing Thread", "Socket Type: " + socketType + "listen() failed", e);
indexUUID++;
}
Log.d("Accept Bluetooth Pairing Thread", "Socket Type: " + socketType +
"BEGIN mAcceptThread" + this);
BluetoothSocket socket = null;
// Listen to the server socket if we're not connected
while (true) { //mState != STATE_CONNECTED) {
try {
// This is a blocking call and will only return on a
// successful connection or an exception
socket = serverSocket.accept();
Log.i("Slave", "server socket found");
// If a connection was accepted
if (socket != null) {
BluetoothNode node = null;
try {
node = new BluetoothNode(socket);
Log.i("connected to", node.getDeviceInformation());
slaveBluetoothNodes.add(node);
indexUUID++;
serverSocket = params[0].listenUsingRfcommWithServiceRecord(NAME_SECURE, MY_UUID_SECURE[indexUUID]);
} catch (IOException e) {
e.printStackTrace();
indexUUID++;
serverSocket = params[0].listenUsingRfcommWithServiceRecord(NAME_SECURE, MY_UUID_SECURE[indexUUID]);
}
}
} catch (IOException e) {
Log.e("Accept Bluetooth Pairing Thread", "Socket Type: " + socketType + "accept() failed", e);
try {
indexUUID++;
serverSocket = params[0].listenUsingRfcommWithServiceRecord(NAME_SECURE, MY_UUID_SECURE[indexUUID]);
} catch (IOException e1) {
Log.e("Accept Bluetooth Pairing Thread", "Socket Type: " + socketType + "listen() failed", e1);
}
}
}
}
}
但即便如此，我在尝试连接到已经与第二台设备建立蓝牙连接的第三台手机上遇到不同的错误，如下所示。
Socket closed. Unable to complete pairing.
java.io.IOException: Service discovery failed
at android.bluetooth.BluetoothSocket$SdpHelper.doSdp(BluetoothSocket.java:406)
at android.bluetooth.BluetoothSocket.connect(BluetoothSocket.java:217)
at com.ablueworld.androidgridcomputingframework.BluetoothManager$ConnectAsyncTask.doInBackground(BluetoothManager.java:270)
at com.ablueworld.androidgridcomputingframework.BluetoothManager$ConnectAsyncTask.doInBackground(BluetoothManager.java:1)
at android.os.AsyncTask$2.call(AsyncTask.java:185)
at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:306)
at java.util.concurrent.FutureTask.run(FutureTask.java:138)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1088)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:581)
at java.lang.Thread.run(Thread.java:1019)
Could not connect to this device
任何人都可以帮助解决这个问题吗？谢谢你。