Android蓝牙通信

Android为蓝牙设备之间的通信封装好了一些调用接口，使得实现Android的蓝牙通信功能并不困难。可通过UUID使两个设备直接建立连接。

具体步骤：

1. 获取BluetoothAdapter实例，注册一个BroadcastReceiver监听蓝牙扫描过程中的状态变化

 

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mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
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IntentFilter filter = new IntentFilter(BluetoothDevice.ACTION_FOUND);
registerReceiver(mReceiver, filter);
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private final BroadcastReceiver mReceiver = new BroadcastReceiver() {
        @Override
        public void onReceive(Context context, Intent intent) {
            String action = intent.getAction();
 
 
            // When discovery finds a device
            if (BluetoothDevice.ACTION_FOUND.equals(action))
            {
                // Get the BluetoothDevice object from the Intent
                // 通过EXTRA_DEVICE附加域来得到一个BluetoothDevice设备
                BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
                 
                // If it's already paired, skip it, because it's been listed already
                // 如果这个设备是不曾配对过的，添加到list列表
                if (device.getBondState() != BluetoothDevice.BOND_BONDED)
                {
                    list.add(new ChatMessage(device.getName() + "\n" + device.getAddress(), false));
                    clientAdapter.notifyDataSetChanged();
                    mListView.setSelection(list.size() - 1);
                }
            // When discovery is finished, change the Activity title
            }
            else if (BluetoothAdapter.ACTION_DISCOVERY_FINISHED.equals(action))
            {
                setProgressBarIndeterminateVisibility(false);
                if (mListView.getCount() == 0)
                {
                    list.add(new ChatMessage("没有发现蓝牙设备", false));
                    clientAdapter.notifyDataSetChanged();
                    mListView.setSelection(list.size() - 1);
                }
            }
        }
    };

 

2. 打开蓝牙(enable)，并设置蓝牙的可见性(可以被其它设备扫描到，客户端是主动发请求的，可不设置，服务端必须设置可见)。

 

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       if (mBluetoothAdapter != null) {
    if (!mBluetoothAdapter.isEnabled()) {
        // 发送打开蓝牙的意图，系统会弹出一个提示对话框
        Intent enableIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
        startActivityForResult(enableIntent, RESULT_FIRST_USER);
         
        // 设置蓝牙的可见性，最大值3600秒，默认120秒，0表示永远可见(作为客户端，可见性可以不设置，服务端必须要设置)
        Intent displayIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_DISCOVERABLE);
        displayIntent.putExtra(BluetoothAdapter.EXTRA_DISCOVERABLE_DURATION, 0);
        startActivity(displayIntent);
         
        // 直接打开蓝牙
        mBluetoothAdapter.enable();
    }
}

 

3. 扫描，startDiscovery()方法是一个很耗性能的操作，在扫描之前可以先使用getBondedDevices()获取已经配对过的设备(可直接连接)，避免不必要的消耗。

 

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  private void scanDevice() {
    // TODO Auto-generated method stub
    if (mBluetoothAdapter.isDiscovering()) {
        mBluetoothAdapter.cancelDiscovery();
    } else {
         
        // 每次扫描前都先判断一下是否存在已经配对过的设备
        Set<bluetoothdevice> pairedDevices = mBluetoothAdapter.getBondedDevices();
        if (pairedDevices.size() > 0) {
            for (BluetoothDevice device : pairedDevices) {
                list.add(new ChatMessage(device.getName() + "\n" + device.getAddress(), true));
            }
        } else {
                list.add(new ChatMessage("No devices have been paired", true));
                clientAdapter.notifyDataSetChanged();
                mListView.setSelection(list.size() - 1);
         }             
             /* 开始搜索 */
             mBluetoothAdapter.startDiscovery();
    }
}</bluetoothdevice>

 

4. 通过Mac地址发送连接请求，在这之前必须使用cancelDiscovery()方法停止扫描。

 

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        mBluetoothAdapter.cancelDiscovery();
 
// 通过Mac地址去尝试连接一个设备
BluetoothDevice device = mBluetoothAdapter.getRemoteDevice(BluetoothMsg.BlueToothAddress);

 

5. 通过UUID使两个设备之间建立连接。

客户端：主动发请求

 

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BluetoothSocket socket = device.createRfcommSocketToServiceRecord(UUID.fromString("00001101-0000-1000-8000-00805F9B34FB"));
                
// 通过socket连接服务器，这是一个阻塞过程，直到连接建立或者连接失效
socket.connect();

 

服务端：接受一个请求

 

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BluetoothServerSocket mServerSocket = mBluetoothAdapter.listenUsingRfcommWithServiceRecord(PROTOCOL_SCHEME_RFCOMM,
                   UUID.fromString("00001101-0000-1000-8000-00805F9B34FB"));      
            
/* 接受客户端的连接请求 */
// 这是一个阻塞过程，直到建立一个连接或者连接失效
// 通过BluetoothServerSocket得到一个BluetoothSocket对象，管理这个连接
BluetoothSocket socket = mServerSocket.accept();

 

6. 通过InputStream／outputStream读写数据流，已达到通信目的。

 

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OutputStream os = socket.getOutputStream();
os.write(msg.getBytes());
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InputStream is = null;
try {
    is = socket.getInputStream();
} catch (IOException e) {
    // TODO Auto-generated catch block
    e.printStackTrace();
}

 

7. 关闭所有线程以及socket，并关闭蓝牙设备(disable)。

 

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        if (mClientThread != null) {
    mClientThread.interrupt();
    mClientThread = null;
}
if (mReadThread != null) {
    mReadThread.interrupt();
    mReadThread = null;
}
try {
    if (socket != null) {
        socket.close();
        socket = null;
    }
} catch (IOException e) {
    // TODO: handle exception
}
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        if (mBluetoothAdapter != null) {
    mBluetoothAdapter.cancelDiscovery();
    // 关闭蓝牙
    mBluetoothAdapter.disable();
}
unregisterReceiver(mReceiver);


主要步骤就是这些，为了能够更好的理解，我将服务器端和客户端的代码分开来写了两个程序，下载地址：http://download.csdn.net/detail/visionliao/8417235

 

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posted @ 2015-02-10 11:02  回忆安在  阅读(506)  评论(0)  编辑  收藏  举报