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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1	mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();

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1 2	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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1 2	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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