蓝牙:服务发现失败

Question

我试图在我的安卓应用程序(在运行4.1.2:客户端的三星手机上)和我的笔记本电脑(Win7，64位:服务器)之间建立蓝牙连接。它总是失败，服务发现失败。

我读过关于这个的各种主题(这里和那里)，但是它并没有解决我的问题。

我有两个问题：

• 什么是众所周知的UUID "00001101-0000-1000-8000-00805F9B34FB“。为什么/什么时候使用它？
• 任何关于调查/解决我的问题的建议都将不胜感激。

备注：

• 我试图建立一个安全和不安全的连接(两者都失败)
• 我能把我的笔记本电脑和Settings>Bluetooth的设备配对
• 正如注释中所建议的那样:我尝试使用一个随机生成的UUID (但两边的UUID相同)，而不是众所周知的UUID，但我仍然有着完全相同的行为。

我有这些权限

<uses-permission android:name="android.permission.BLUETOOTH"/>
<uses-permission android:name="android.permission.BLUETOOTH_ADMIN"/>

编辑

我没有在客户端重新编码UUID，而是尝试了以下操作(但仍然得到相同的错误)：

UUID uuid = bluetoothDevice.getUuids()[bluetoothDevice.getUuids().length-1].getUuid();

回显服务器的UUID始终是数组中的最后一个。

端编辑

以下是客户端的相关日志：

08-22 12:30:28.627: ERROR/BluetoothService.cpp(12008): stopDiscoveryNative: D-Bus error in StopDiscovery: org.bluez.Error.Failed (Invalid discovery session)
08-22 12:30:28.647: INFO/BluetoothSocket.cpp(18030): Setting Master socket option
08-22 12:30:28.647: VERBOSE/BluetoothSocket.cpp(18030): ...fd 43 created (RFCOMM, lm = 7)
08-22 12:30:28.687: DEBUG/BluetoothPolicyService(12008): getAllowBluetoothDataTransfer - showMsg: true
08-22 12:30:28.687: DEBUG/BluetoothPolicyService(12008): MDM: isProfileEnabled = true
08-22 12:30:28.697: DEBUG/BluetoothUtils(18030): isSocketAllowedBySecurityPolicy start : device null
08-22 12:30:28.727: ERROR/BluetoothEventLoop.cpp(12008): onCreateDeviceResult: D-Bus error: org.bluez.Error.AlreadyExists (Already Exists)
08-22 12:30:28.727: VERBOSE/BluetoothService.cpp(12008): discoverServicesNative
08-22 12:30:28.727: VERBOSE/BluetoothService.cpp(12008): ... Object Path = /org/bluez/12635/hci0/dev_00_09_DD_50_88_54
08-22 12:30:28.727: VERBOSE/BluetoothService.cpp(12008): ... Pattern = , strlen = 0
08-22 12:30:29.138: VERBOSE/BluetoothEventLoop.cpp(12008): event_filter: Received signal org.bluez.Device:PropertyChanged from /org/bluez/12635/hci0/dev_00_09_DD_50_88_54
08-22 12:30:29.138: DEBUG/BluetoothEventLoop(12008): Device property changed
08-22 12:30:32.141: DEBUG/BluetoothA2DPStateReceiver(15827): BluetoothA2DPStateReceiver constructor call()
08-22 12:30:32.141: DEBUG/BluetoothA2DPStateReceiver(15827): onReceive(): action = android.bluetooth.device.action.ACL_CONNECTED
08-22 12:30:32.141: DEBUG/BluetoothA2DPStateReceiver(15827): ACTION_ACL_CONNECTED
08-22 12:30:32.141: DEBUG/BluetoothA2DPSinkInfo(15827): checkBlackListCarkit() : isBlackListCarkit false
08-22 12:30:32.161: DEBUG/BluetoothNotiBroadcastReceiver(15910): onReceive
08-22 12:30:40.749: ERROR/Bluetooth(18030): Cannot connect
    java.io.IOException: Service discovery failed
    at android.bluetooth.BluetoothSocket$SdpHelper.doSdp(BluetoothSocket.java:475)
    at android.bluetooth.BluetoothSocket.connect(BluetoothSocket.java:241)
    at com.company.BlueToothTestActivity.open(BlueToothTestActivity.java:48)
    at com.company.BlueToothTestActivity$1.run(BlueToothTestActivity.java:29)
08-22 12:30:40.749: WARN/Bluetooth(18030): Unable to open connection !

下面是再现错误的代码(它是简化的版本，它编译和再现错误--至少在我的硬件上是这样)。

客户端

import android.app.Activity;
import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;
import android.bluetooth.BluetoothSocket;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.LinearLayout;

import java.io.IOException;
import java.util.UUID;

public class BlueToothTestActivity extends Activity {

private String macAddress = "00:09:DD:50:88:54";  //hardcoded laptop macAddress
private BluetoothAdapter mBluetoothAdapter;
private BluetoothDevice bluetoothDevice;
private BluetoothSocket socket;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);   
    Thread bluetoothClientThread = new Thread(){
        @Override
        public void run() {
            if(open()){
                Log.i("Bluetooth","Connection is open !");
            }else{
                Log.w("Bluetooth","Unable to open connection !");
            }
        }
    };
    bluetoothClientThread.start();
    initUI();
}

public boolean open() {
    mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
    bluetoothDevice = mBluetoothAdapter.getRemoteDevice(macAddress);
    String BT_UUID = "00001101-0000-1000-8000-00805F9B34FB";
    try {
        mBluetoothAdapter.cancelDiscovery();
        //socket = bluetoothDevice.createInsecureRfcommSocketToServiceRecord(UUID.fromString(BT_UUID));
        socket = bluetoothDevice.createRfcommSocketToServiceRecord(UUID.fromString(BT_UUID));
        socket.connect(); //Block 12 sec here, then throw the exception.
        return true;
    } catch (IOException e) {
        try {
            socket.close();
        } catch (IOException closeException) { }
        Log.e("Bluetooth", "Cannot connect", e);
        return false;
    }
}

private void initUI(){
    LinearLayout linearLayout = new LinearLayout(this);
    Button finish = new Button(this);
    finish.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            if(socket!=null){
                try {
                    socket.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            BlueToothTestActivity.this.finish();
        }
    });
    finish.setText("Exit");
    linearLayout.addView(finish);
    setContentView(linearLayout);
}
}

服务器是一个简单的回显服务器(基于Bluecove，我从这里获取了代码：http://www.miniware.net/mobile/articles/viewarticle.php?id=22)

服务器

import java.io.*;
import javax.bluetooth.*;
import javax.microedition.io.*;

// sample code from : http://www.miniware.net/mobile/articles/viewarticle.php?id=22   (Nikos Fotiou)
public class EchoServer {
    public final UUID uuid = new UUID("0000110100001000800000805F9B34FB",false);
    public final String name = "EchoServer";                       //the name of the service
    public final String url  =  "btspp://localhost:" + uuid + ";name=" + name  + ";authenticate=false;encrypt=false;";
    LocalDevice local = null;
    StreamConnectionNotifier server = null;
    StreamConnection conn = null;

    public EchoServer() {
    try {
        System.out.println("Setting device to be discoverable...");
        local = LocalDevice.getLocalDevice();
        local.setDiscoverable(DiscoveryAgent.GIAC);
        System.out.println("Start service:"+url);
        server = (StreamConnectionNotifier)Connector.open(url);
        System.out.println("Waiting for incoming connection...");
        conn = server.acceptAndOpen();  // stop and wait here
        System.out.println("Client Connected..."); //never reach this line
        DataInputStream din   = new DataInputStream(conn.openInputStream());
        while(true){
            String cmd = "";
            char c;
            while (((c = din.readChar()) > 0) && (c!='\n') ){
                cmd = cmd + c;
            }
            System.out.println("Received " + cmd);
        }
    } catch (Exception  e) {
        System.err.println("Exception Occured: " + e.toString());
        e.printStackTrace();
    }
}

public static void main (String args[]){
    EchoServer echoserver = new EchoServer();
}

}

服务器pom.xml

<dependencies>
    <dependency>
        <groupId>net.sf.bluecove</groupId>
        <artifactId>bluecove</artifactId>
        <version>2.1.1-SNAPSHOT</version>
    </dependency>
</dependencies>

<repositories>
    <repository>
        <id>pyx4me-web-snapshot</id>
        <url>http://www.pyx4me.com/maven2-snapshot</url>
        <snapshots>
            <enabled>true</enabled>
        </snapshots>
        <releases>
            <enabled>false</enabled>
        </releases>
    </repository>
</repositories>

Answer 1

尝试使用的UUID是。它可以在如下代码中声明：

private static final UUID BLUETOOTH_SPP_UUID =
                UUID.fromString("00001101-0000-1000-8000-00805f9b34fb");

我用Windows 8笔记本电脑和Nexus S尝试了你的代码。首先，我不得不对Nexus上的设备进行配对。然后我启动服务器并使用蓝牙SPP应用程序来测试连接。效果完美无瑕。然后我启动了你的代码，它也起作用了。

当服务器端未启动时，我可以复制“服务发现失败”异常。另外，在我用createRfcommSocket方法扫描了所有30个通道之后，手机上的蓝牙堆栈被破坏了，我不得不重新启动设备。

总之，为了确保你能够沟通：

1. 在笔记本电脑上，确保蓝牙处于可被发现的状态。
2. (可选)关闭UAC并使用管理帐户确保您不会遇到任何安全漏洞(我不需要这样做，但在第二次启动时，防火墙必须为eclipse打开以启用调试)
3. 重新启动电话
4. 打电话来的一对
5. 使用SPP UUID，而不是自定义UUID
6. 通过在System.out.println(local.getBluetoothAddress());调用之前的某个地方添加acceptAndOpen()，确保使用正确的mac地址。
7. 测试与第三方应用程序的连接从游戏商店。我在命令行模式下使用了这一个。只需要测试连接。
8. 更新MAC地址并运行应用程序
9. 应该管用的。

下面是我从运行中得到的输出：

Start service:btspp://localhost:0000110100001000800000805f9b34fb;name=EchoServer;authenticate=false;encrypt=false;
MAC 402CF454215C
Waiting for incoming connection...
Client Connected...
Exception Occured: java.io.EOFException
BlueCove stack shutdown completed
java.io.EOFException
    at java.io.DataInputStream.readChar(Unknown Source)
    at examples.bluetooth_spp_server.EchoServer.<init>(EchoServer.java:30)
    at examples.bluetooth_spp_server.EchoServer.main(EchoServer.java:42)

为了完整起见，以下是在各种条件下返回的错误

• Windows蓝牙关闭：javax.bluetooth.BluetoothStateException: Bluetooth not detected
• 安卓蓝牙关闭：java.io.IOException: Unable to start Service Discovery
• Windows服务器未运行：java.io.IOException: Service discovery failed
• 未配对：TimeoutException

理论上说，在启动安全连接时，配对应该会自动发生，但在现实中，配对对话框并不是在所有情况下都会出现在电话或Windows中。这是一个不确定性因素，如果失败发生，就需要考虑这个因素。

Answer 2

a) UUID是一个串口UUID，主要用于使用不讲SDP协议的设备，例如小型嵌入式RFCOMM设备。

( b)检查你的手机是否打开了蓝牙。