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();

}

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