IOException:读取失败,套接字可能关闭 - Android 4.3上的蓝牙

Question

目前我正试图在我的Nexus 7(2012)上使用Android 4.3(Build JWR66Y,我猜第二次4.3更新)打开BluetoothSocket时遇到一个奇怪的异常.我已经看到了一些相关的帖子(例如/sf/ask/955386141/),但似乎没有提供此问题的解决方法.此外,正如在这些线程中所建议的那样,重新配对没有帮助,并且不断尝试连接(通过愚蠢的循环)也没有任何效果.

我正在处理嵌入式设备(noname OBD-II车载适配器,类似于http://images04.olx.com/ui/15/53/76/1316534072_254254776_2-OBD-II-BLUTOOTH-ADAPTERSCLEAR-CHECK-ENGINE-灯光与你的电话-Oceanside.jpg).我的Android 2.3.7手机连接没有任何问题,同事的Xperia(Android 4.1.2)也可以使用.另一个Google Nexus(我不知道'One'或'S',但不是'4')也因Android 4.3而失败.

这是连接建立的片段.它在自己的Thread中运行,在Service中创建.

private class ConnectThread extends Thread {

    private static final UUID EMBEDDED_BOARD_SPP = UUID
        .fromString("00001101-0000-1000-8000-00805F9B34FB");

    private BluetoothAdapter adapter;
    private boolean secure;
    private BluetoothDevice device;
    private List<UUID> uuidCandidates;
    private int candidate;
    protected boolean started;

    public ConnectThread(BluetoothDevice device, boolean secure) {
        logger.info("initiliasing connection to device "+device.getName() +" / "+ device.getAddress());
        adapter = BluetoothAdapter.getDefaultAdapter();
        this.secure = secure;
        this.device = device;

        setName("BluetoothConnectThread");

        if (!startQueryingForUUIDs()) {
            this.uuidCandidates = Collections.singletonList(EMBEDDED_BOARD_SPP);
            this.start();
        } else{
            logger.info("Using UUID discovery mechanism.");
        }
        /*
         * it will start upon the broadcast receive otherwise
         */
    }

    private boolean startQueryingForUUIDs() {
        Class<?> cl = BluetoothDevice.class;

        Class<?>[] par = {};
        Method fetchUuidsWithSdpMethod;
        try {
            fetchUuidsWithSdpMethod = cl.getMethod("fetchUuidsWithSdp", par);
        } catch (NoSuchMethodException e) {
            logger.warn(e.getMessage());
            return false;
        }

        Object[] args = {};
        try {
            BroadcastReceiver receiver = new BroadcastReceiver() {
                @Override
                public void onReceive(Context context, Intent intent) {
                    BluetoothDevice deviceExtra = intent.getParcelableExtra("android.bluetooth.device.extra.DEVICE");
                    Parcelable[] uuidExtra = intent.getParcelableArrayExtra("android.bluetooth.device.extra.UUID");

                    uuidCandidates = new ArrayList<UUID>();
                    for (Parcelable uuid : uuidExtra) {
                        uuidCandidates.add(UUID.fromString(uuid.toString()));
                    }

                    synchronized (ConnectThread.this) {
                        if (!ConnectThread.this.started) {
                            ConnectThread.this.start();
                            ConnectThread.this.started = true;
                            unregisterReceiver(this);
                        }

                    }
                }

            };
            registerReceiver(receiver, new IntentFilter("android.bleutooth.device.action.UUID"));
            registerReceiver(receiver, new IntentFilter("android.bluetooth.device.action.UUID"));

            fetchUuidsWithSdpMethod.invoke(device, args);
        } catch (IllegalArgumentException e) {
            logger.warn(e.getMessage());
            return false;
        } catch (IllegalAccessException e) {
            logger.warn(e.getMessage());
            return false;
        } catch (InvocationTargetException e) {
            logger.warn(e.getMessage());
            return false;
        }           

        return true;
    }

    public void run() {
        boolean success = false;
        while (selectSocket()) {

            if (bluetoothSocket == null) {
                logger.warn("Socket is null! Cancelling!");
                deviceDisconnected();
                openTroubleshootingActivity(TroubleshootingActivity.BLUETOOTH_EXCEPTION);
            }

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

            // Make a connection to the BluetoothSocket
            try {
                // This is a blocking call and will only return on a
                // successful connection or an exception
                bluetoothSocket.connect();
                success = true;
                break;

            } catch (IOException e) {
                // Close the socket
                try {
                    shutdownSocket();
                } catch (IOException e2) {
                    logger.warn(e2.getMessage(), e2);
                }
            }
        }

        if (success) {
            deviceConnected();
        } else {
            deviceDisconnected();
            openTroubleshootingActivity(TroubleshootingActivity.BLUETOOTH_EXCEPTION);
        }
    }

    private boolean selectSocket() {
        if (candidate >= uuidCandidates.size()) {
            return false;
        }

        BluetoothSocket tmp;
        UUID uuid = uuidCandidates.get(candidate++);
        logger.info("Attempting to connect to SDP "+ uuid);
        try {
            if (secure) {
                tmp = device.createRfcommSocketToServiceRecord(
                        uuid);
            } else {
                tmp = device.createInsecureRfcommSocketToServiceRecord(
                        uuid);
            }
            bluetoothSocket = tmp;
            return true;
        } catch (IOException e) {
            logger.warn(e.getMessage() ,e);
        }

        return false;
    }

}

代码失败了bluetoothSocket.connect().我得到了一个java.io.IOException: read failed, socket might closed, read ret: -1.这是GitHub上的相应源代码:https://github.com/android/platform_frameworks_base/blob/android-4.3_r2/core/java/android/bluetooth/BluetoothSocket.java#L504 它通过readInt()调用,从https调用://github.com/android/platform_frameworks_base/blob/android-4.3_r2/core/java/android/bluetooth/BluetoothSocket.java#L319

使用的套接字的某些元数据转储导致以下信息.这些在Nexus 7和我的2.3.7手机上完全相同.

Bluetooth Device 'OBDII'
Address: 11:22:33:DD:EE:FF
Bond state: 12 (bonded)
Type: 1
Class major version: 7936
Class minor version: 7936
Class Contents: 0
Contents: 0

我有一些其他OBD-II适配器(更多的扩展),他们都工作.有没有机会,我错过了什么或者这可能是Android中的错误？

Answer 1

我终于找到了解决方法.神奇的是在引擎盖下隐藏的BluetoothDevice类(见https://github.com/android/platform_frameworks_base/blob/android-4.3_r2/core/java/android/bluetooth/BluetoothDevice.java#L1037).

现在,当我收到例外,我实例化一个后备BluetoothSocket,类似于下面的源代码.如您所见,createRfcommSocket通过反射调用隐藏方法.我不知道为什么隐藏这个方法.源代码定义它public好像......

Class<?> clazz = tmp.getRemoteDevice().getClass();
Class<?>[] paramTypes = new Class<?>[] {Integer.TYPE};

Method m = clazz.getMethod("createRfcommSocket", paramTypes);
Object[] params = new Object[] {Integer.valueOf(1)};

fallbackSocket = (BluetoothSocket) m.invoke(tmp.getRemoteDevice(), params);
fallbackSocket.connect();

connect()那么不会再失败了.我还遇到了一些问题.基本上,这有时会阻塞并失败.重新启动SPP-设备(插上腾飞/插入)帮助在这种情况下.有时我也在之后得到另一个配对要求connect()即使设备已粘合.

更新:

这是一个完整的类,包含一些嵌套类.对于真正的实现,这些可以作为单独的类进行.

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.lang.reflect.Method;
import java.util.List;
import java.util.UUID;

import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;
import android.bluetooth.BluetoothSocket;
import android.util.Log;

public class BluetoothConnector {

    private BluetoothSocketWrapper bluetoothSocket;
    private BluetoothDevice device;
    private boolean secure;
    private BluetoothAdapter adapter;
    private List<UUID> uuidCandidates;
    private int candidate;


    /**
     * @param device the device
     * @param secure if connection should be done via a secure socket
     * @param adapter the Android BT adapter
     * @param uuidCandidates a list of UUIDs. if null or empty, the Serial PP id is used
     */
    public BluetoothConnector(BluetoothDevice device, boolean secure, BluetoothAdapter adapter,
            List<UUID> uuidCandidates) {
        this.device = device;
        this.secure = secure;
        this.adapter = adapter;
        this.uuidCandidates = uuidCandidates;

        if (this.uuidCandidates == null || this.uuidCandidates.isEmpty()) {
            this.uuidCandidates = new ArrayList<UUID>();
            this.uuidCandidates.add(UUID.fromString("00001101-0000-1000-8000-00805F9B34FB"));
        }
    }

    public BluetoothSocketWrapper connect() throws IOException {
        boolean success = false;
        while (selectSocket()) {
            adapter.cancelDiscovery();

            try {
                bluetoothSocket.connect();
                success = true;
                break;
            } catch (IOException e) {
                //try the fallback
                try {
                    bluetoothSocket = new FallbackBluetoothSocket(bluetoothSocket.getUnderlyingSocket());
                    Thread.sleep(500);                  
                    bluetoothSocket.connect();
                    success = true;
                    break;  
                } catch (FallbackException e1) {
                    Log.w("BT", "Could not initialize FallbackBluetoothSocket classes.", e);
                } catch (InterruptedException e1) {
                    Log.w("BT", e1.getMessage(), e1);
                } catch (IOException e1) {
                    Log.w("BT", "Fallback failed. Cancelling.", e1);
                }
            }
        }

        if (!success) {
            throw new IOException("Could not connect to device: "+ device.getAddress());
        }

        return bluetoothSocket;
    }

    private boolean selectSocket() throws IOException {
        if (candidate >= uuidCandidates.size()) {
            return false;
        }

        BluetoothSocket tmp;
        UUID uuid = uuidCandidates.get(candidate++);

        Log.i("BT", "Attempting to connect to Protocol: "+ uuid);
        if (secure) {
            tmp = device.createRfcommSocketToServiceRecord(uuid);
        } else {
            tmp = device.createInsecureRfcommSocketToServiceRecord(uuid);
        }
        bluetoothSocket = new NativeBluetoothSocket(tmp);

        return true;
    }

    public static interface BluetoothSocketWrapper {

        InputStream getInputStream() throws IOException;

        OutputStream getOutputStream() throws IOException;

        String getRemoteDeviceName();

        void connect() throws IOException;

        String getRemoteDeviceAddress();

        void close() throws IOException;

        BluetoothSocket getUnderlyingSocket();

    }


    public static class NativeBluetoothSocket implements BluetoothSocketWrapper {

        private BluetoothSocket socket;

        public NativeBluetoothSocket(BluetoothSocket tmp) {
            this.socket = tmp;
        }

        @Override
        public InputStream getInputStream() throws IOException {
            return socket.getInputStream();
        }

        @Override
        public OutputStream getOutputStream() throws IOException {
            return socket.getOutputStream();
        }

        @Override
        public String getRemoteDeviceName() {
            return socket.getRemoteDevice().getName();
        }

        @Override
        public void connect() throws IOException {
            socket.connect();
        }

        @Override
        public String getRemoteDeviceAddress() {
            return socket.getRemoteDevice().getAddress();
        }

        @Override
        public void close() throws IOException {
            socket.close();
        }

        @Override
        public BluetoothSocket getUnderlyingSocket() {
            return socket;
        }

    }

    public class FallbackBluetoothSocket extends NativeBluetoothSocket {

        private BluetoothSocket fallbackSocket;

        public FallbackBluetoothSocket(BluetoothSocket tmp) throws FallbackException {
            super(tmp);
            try
            {
              Class<?> clazz = tmp.getRemoteDevice().getClass();
              Class<?>[] paramTypes = new Class<?>[] {Integer.TYPE};
              Method m = clazz.getMethod("createRfcommSocket", paramTypes);
              Object[] params = new Object[] {Integer.valueOf(1)};
              fallbackSocket = (BluetoothSocket) m.invoke(tmp.getRemoteDevice(), params);
            }
            catch (Exception e)
            {
                throw new FallbackException(e);
            }
        }

        @Override
        public InputStream getInputStream() throws IOException {
            return fallbackSocket.getInputStream();
        }

        @Override
        public OutputStream getOutputStream() throws IOException {
            return fallbackSocket.getOutputStream();
        }


        @Override
        public void connect() throws IOException {
            fallbackSocket.connect();
        }


        @Override
        public void close() throws IOException {
            fallbackSocket.close();
        }

    }

    public static class FallbackException extends Exception {

        /**
         * 
         */
        private static final long serialVersionUID = 1L;

        public FallbackException(Exception e) {
            super(e);
        }

    }
}

Answer 2

好吧,我的代码有同样的问题,这是因为Android 4.2蓝牙堆栈已经改变了.所以我的代码在android <4.2的设备上正常运行,在其他设备上我得到了着名的异常"读取失败,套接字可能关闭或超时,读取ret:-1"

问题在于socket.mPort参数.使用时创建套接字socket = device.createRfcommSocketToServiceRecord(SERIAL_UUID);,mPort获取整数值" -1 ",此值似乎不适用于android> = 4.2,因此您需要将其设置为" 1 ".坏消息是createRfcommSocketToServiceRecord只接受UUID作为参数而不是mPort我们必须使用其他方法.@matthes发布的答案也适用于我,但我简化了它:socket =(BluetoothSocket) device.getClass().getMethod("createRfcommSocket", new Class[] {int.class}).invoke(device,1);.我们需要使用两个套接字attribs,第二个作为后备.

所以代码是(用于连接到ELM327设备上的SPP):

BluetoothAdapter btAdapter = BluetoothAdapter.getDefaultAdapter();

    if (btAdapter.isEnabled()) {
        SharedPreferences prefs_btdev = getSharedPreferences("btdev", 0);
        String btdevaddr=prefs_btdev.getString("btdevaddr","?");

        if (btdevaddr != "?")
        {
            BluetoothDevice device = btAdapter.getRemoteDevice(btdevaddr);

            UUID SERIAL_UUID = UUID.fromString("00001101-0000-1000-8000-00805f9b34fb"); // bluetooth serial port service
            //UUID SERIAL_UUID = device.getUuids()[0].getUuid(); //if you don't know the UUID of the bluetooth device service, you can get it like this from android cache

            BluetoothSocket socket = null;

            try {
                socket = device.createRfcommSocketToServiceRecord(SERIAL_UUID);
            } catch (Exception e) {Log.e("","Error creating socket");}

            try {
                socket.connect();
                Log.e("","Connected");
            } catch (IOException e) {
                Log.e("",e.getMessage());
                try {
                    Log.e("","trying fallback...");

                    socket =(BluetoothSocket) device.getClass().getMethod("createRfcommSocket", new Class[] {int.class}).invoke(device,1);
                    socket.connect();

                    Log.e("","Connected");
                }
             catch (Exception e2) {
                 Log.e("", "Couldn't establish Bluetooth connection!");
              }
            }
        }
        else
        {
            Log.e("","BT device not selected");
        }
    }

Answer 3

首先,如果您需要与蓝牙2.x设备通信,此文档说明:

提示:如果要连接蓝牙串行板,请尝试使用众所周知的SPP UUID 00001101-0000-1000-8000-00805F9B34FB.但是,如果您要连接到Android对等设备,请生成您自己的唯一UUID.

我认为它不会起作用,但只有用00001101-0000-1000-8000-00805F9B34FB它取代UUID 才有效.然而,这个代码似乎处理的SDK版本的问题,您只需更换功能device.createRfcommSocketToServiceRecord(mMyUuid);与tmp = createBluetoothSocket(mmDevice);定义以下方法之后:

private BluetoothSocket createBluetoothSocket(BluetoothDevice device)
    throws IOException {
    if(Build.VERSION.SDK_INT >= 10){
        try {
            final Method m = device.getClass().getMethod("createInsecureRfcommSocketToServiceRecord", new Class[] { UUID.class });
            return (BluetoothSocket) m.invoke(device, mMyUuid);
        } catch (Exception e) {
            Log.e(TAG, "Could not create Insecure RFComm Connection",e);
        }
    }
    return  device.createRfcommSocketToServiceRecord(mMyUuid);
}

源代码不是我的,但来自这个网站.

Answer 4

我有与此处描述的症状相同的症状.我可以连接一次到蓝牙打印机,但后续连接失败,"套接字关闭",无论我做什么.

我发现这里描述的变通方法是必要的,这有点奇怪.经过我的代码后,我发现我忘了关闭套接字的InputStream和OutputSteram而没有正确终止ConnectedThreads.

我使用的ConnectedThread与此处的示例相同:

http://developer.android.com/guide/topics/connectivity/bluetooth.html

请注意,ConnectThread和ConnectedThread是两个不同的类.

无论什么类启动ConnectedThread都必须在线程上调用interrupt()和cancel().我在ConnectedTread.cancel()方法中添加了mmInStream.close()和mmOutStream.close().

正确关闭线程/流/套接字后,我可以创建新的套接字而没有任何问题.

Answer 5

好吧,我实际上发现了这个问题.

尝试使用连接的大多数人socket.Connect();都会调用异常Java.IO.IOException: read failed, socket might closed, read ret: -1.

在某些情况下,它还取决于您的蓝牙设备,因为有两种不同类型的蓝牙,即BLE(低能耗)和经典.

如果您想检查蓝牙设备的类型,请输入以下代码:

        String checkType;
        var listDevices = BluetoothAdapter.BondedDevices;
        if (listDevices.Count > 0)
        {
            foreach (var btDevice in listDevices)
            {
                if(btDevice.Name == "MOCUTE-032_B52-CA7E")
                {
                    checkType = btDevice.Type.ToString();
                    Console.WriteLine(checkType);
                }
            }
        }

我一直在努力解决这个问题,但从今天起我就找到了问题所在.不幸的是,@matthes的解决方案仍然存在一些问题,正如他已经说过的那样,但这是我的解决方案.

目前我在Xamarin Android工作,但这也适用于其他平台.

解

如果有多个配对设备,则应删除其他配对设备.因此,请仅保留您要连接的那个(请参阅右图).

在左图中,您看到我有两个配对设备,即"MOCUTE-032_B52-CA7E"和"Blue Easy".这是问题,但我不知道为什么会出现这个问题.也许蓝牙协议试图从另一个蓝牙设备获取一些信息.

然而,这些socket.Connect();作品现在很好,没有任何问题.所以我只是想分享这个,因为这个错误真的很烦人.

祝好运!

Answer 6

你把 registerReceiver(receiver, new IntentFilter("android.bleutooth.device.action.UUID")); "蓝牙"拼写为"bleutooth".

Answer 7

在较新版本的Android上，我收到此错误，因为当我尝试连接到套接字时，适配器仍在发现。即使我在Bluetooth适配器上调用了cancelDiscovery方法，我也必须等到通过动作BluetoothAdapter.ACTION_DISCOVERY_FINISHED调用了BroadcastReceiver的onReceive（）方法的回调。

等待适配器停止发现后，套接字上的connect调用就成功了。

Answer 8

如果有人在使用 Kotlin 时遇到问题，我必须按照已接受的答案进行一些修改：

fun print(view: View, text: String) {
    var adapter = BluetoothAdapter.getDefaultAdapter();
    var pairedDevices = adapter.getBondedDevices()
    var uuid = UUID.fromString("00001101-0000-1000-8000-00805F9B34FB")
    if (pairedDevices.size > 0) {
        for (device in pairedDevices) {
            var s = device.name
            if (device.getName().equals(printerName, ignoreCase = true)) {
                Thread {
                    var socket = device.createInsecureRfcommSocketToServiceRecord(uuid)
                    var clazz = socket.remoteDevice.javaClass
                    var paramTypes = arrayOf<Class<*>>(Integer.TYPE)
                    var m = clazz.getMethod("createRfcommSocket", *paramTypes)
                    var fallbackSocket = m.invoke(socket.remoteDevice, Integer.valueOf(1)) as BluetoothSocket
                    try {
                        fallbackSocket.connect()
                        var stream = fallbackSocket.outputStream
                        stream.write(text.toByteArray(Charset.forName("UTF-8")))
                    } catch (e: Exception) {
                        e.printStackTrace()
                        Snackbar.make(view, "An error occurred", Snackbar.LENGTH_SHORT).show()
                    }
                }.start()
            }
        }
    }
}

希望能帮助到你