蓝牙是一种支持设备短距离传输数据的无线技术。android在2.0以后提供了这方面的支持。 从查找蓝牙设备到能够相互通信要经过几个基本步骤(本机做为服务器): 1.设置权限 在manifest中配置
Xml代码
- <uses-permission android:name="android.permission.BLUETOOTH"/>
- <uses-permission android:name="android.permission.BLUETOOTH_ADMIN"/>
<uses-permission android:name="android.permission.BLUETOOTH"/> <uses-permission android:name="android.permission.BLUETOOTH_ADMIN"/>
2.启动蓝牙 首先要查看本机是否支持蓝牙,获取BluetoothAdapter蓝牙适配器对象
Java代码
- BluetoothAdapter mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
- if(mBluetoothAdapter == null){
- //表明此手机不支持蓝牙
- return;
- }
- if(!mBluetoothAdapter.isEnabled()){ //蓝牙未开启,则开启蓝牙
- Intent enableIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
- startActivityForResult(enableIntent, REQUEST_ENABLE_BT);
- }
- //......
- public void onActivityResult(int requestCode, int resultCode, Intent data){
- if(requestCode == REQUEST_ENABLE_BT){
- if(requestCode == RESULT_OK){
- //蓝牙已经开启
- }
- }
- }
BluetoothAdapter mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter(); if(mBluetoothAdapter == null){ //表明此手机不支持蓝牙 return; } if(!mBluetoothAdapter.isEnabled()){ //蓝牙未开启,则开启蓝牙 Intent enableIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE); startActivityForResult(enableIntent, REQUEST_ENABLE_BT); } //...... public void onActivityResult(int requestCode, int resultCode, Intent data){ if(requestCode == REQUEST_ENABLE_BT){ if(requestCode == RESULT_OK){ //蓝牙已经开启 } } }
3。发现蓝牙设备 这里可以细分为几个方面 (1)使本机蓝牙处于可见(即处于易被搜索到状态),便于其他设备发现本机蓝牙
Java代码
- //使本机蓝牙在300秒内可被搜索
- private void ensureDiscoverable() {
- if (mBluetoothAdapter.getScanMode() !=
- BluetoothAdapter.SCAN_MODE_CONNECTABLE_DISCOVERABLE) {
- Intent discoverableIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_DISCOVERABLE);
- discoverableIntent.putExtra(BluetoothAdapter.EXTRA_DISCOVERABLE_DURATION, 300);
- startActivity(discoverableIntent);
- }
- }
//使本机蓝牙在300秒内可被搜索 private void ensureDiscoverable() { if (mBluetoothAdapter.getScanMode() != BluetoothAdapter.SCAN_MODE_CONNECTABLE_DISCOVERABLE) { Intent discoverableIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_DISCOVERABLE); discoverableIntent.putExtra(BluetoothAdapter.EXTRA_DISCOVERABLE_DURATION, 300); startActivity(discoverableIntent); } }
(2)查找已经配对的蓝牙设备,即以前已经配对过的设备
Java代码
- Set<BluetoothDevice> pairedDevices = mBluetoothAdapter.getBondedDevices();
- if (pairedDevices.size() > 0) {
- findViewById(R.id.title_paired_devices).setVisibility(View.VISIBLE);
- for (BluetoothDevice device : pairedDevices) {
- //device.getName() +" "+ device.getAddress());
- }
- } else {
- mPairedDevicesArrayAdapter.add("没有找到已匹对的设备");
- }
Set<BluetoothDevice> pairedDevices = mBluetoothAdapter.getBondedDevices(); if (pairedDevices.size() > 0) { findViewById(R.id.title_paired_devices).setVisibility(View.VISIBLE); for (BluetoothDevice device : pairedDevices) { //device.getName() +" "+ device.getAddress()); } } else { mPairedDevicesArrayAdapter.add("没有找到已匹对的设备"); }
(3)通过mBluetoothAdapter.startDiscovery();搜索设备,要获得此搜索的结果需要注册 一个BroadcastReceiver来获取。先注册再获取信息,然后处理
Java代码
- //注册,当一个设备被发现时调用onReceive
- IntentFilter filter = new IntentFilter(BluetoothDevice.ACTION_FOUND);
- this.registerReceiver(mReceiver, filter);
- //当搜索结束后调用onReceive
- filter = new IntentFilter(BluetoothAdapter.ACTION_DISCOVERY_FINISHED);
- this.registerReceiver(mReceiver, filter);
- //.......
- private BroadcastReceiver mReceiver = new BroadcastReceiver() {
- @Override
- public void onReceive(Context context, Intent intent) {
- String action = intent.getAction();
- if(BluetoothDevice.ACTION_FOUND.equals(action)){
- BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
- // 已经配对的则跳过
- if (device.getBondState() != BluetoothDevice.BOND_BONDED) {
- mNewDevicesArrayAdapter.add(device.getName() + "\n" + device.getAddress()); //保存设备地址与名字
- }
- }else if (BluetoothAdapter.ACTION_DISCOVERY_FINISHED.equals(action)) { //搜索结束
- if (mNewDevicesArrayAdapter.getCount() == 0) {
- mNewDevicesArrayAdapter.add("没有搜索到设备");
- }
- }
- }
- };
//注册,当一个设备被发现时调用onReceive IntentFilter filter = new IntentFilter(BluetoothDevice.ACTION_FOUND); this.registerReceiver(mReceiver, filter); //当搜索结束后调用onReceive filter = new IntentFilter(BluetoothAdapter.ACTION_DISCOVERY_FINISHED); this.registerReceiver(mReceiver, filter); //....... private BroadcastReceiver mReceiver = new BroadcastReceiver() { @Override public void onReceive(Context context, Intent intent) { String action = intent.getAction(); if(BluetoothDevice.ACTION_FOUND.equals(action)){ BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE); // 已经配对的则跳过 if (device.getBondState() != BluetoothDevice.BOND_BONDED) { mNewDevicesArrayAdapter.add(device.getName() + "\n" + device.getAddress()); //保存设备地址与名字 } }else if (BluetoothAdapter.ACTION_DISCOVERY_FINISHED.equals(action)) { //搜索结束 if (mNewDevicesArrayAdapter.getCount() == 0) { mNewDevicesArrayAdapter.add("没有搜索到设备"); } } } };
4.建立连接 查找到设备 后,则需要建立本机与其他设备之间的连接。 一般用本机搜索其他蓝牙设备时,本机可以作为一个服务端,接收其他设备的连接。 启动一个服务器端的线程,死循环等待客户端的连接,这与ServerSocket极为相似。 这个线程在准备连接之前启动
Java代码
- //UUID可以看做一个端口号
- private static final UUID MY_UUID =
- UUID.fromString("fa87c0d0-afac-11de-8a39-0800200c9a66");
- //像一个服务器一样时刻监听是否有连接建立
- private class AcceptThread extends Thread{
- private BluetoothServerSocket serverSocket;
- public AcceptThread(boolean secure){
- BluetoothServerSocket temp = null;
- try {
- temp = mBluetoothAdapter.listenUsingRfcommWithServiceRecord(
- NAME_INSECURE, MY_UUID);
- } catch (IOException e) {
- Log.e("app", "listen() failed", e);
- }
- serverSocket = temp;
- }
- public void run(){
- BluetoothSocket socket=null;
- while(true){
- try {
- socket = serverSocket.accept();
- } catch (IOException e) {
- Log.e("app", "accept() failed", e);
- break;
- }
- }
- if(socket!=null){
- //此时可以新建一个数据交换线程,把此socket传进去
- }
- }
- //取消监听
- public void cancel(){
- try {
- serverSocket.close();
- } catch (IOException e) {
- Log.e("app", "Socket Type" + socketType + "close() of server failed", e);
- }
- }
- }
//UUID可以看做一个端口号 private static final UUID MY_UUID = UUID.fromString("fa87c0d0-afac-11de-8a39-0800200c9a66"); //像一个服务器一样时刻监听是否有连接建立 private class AcceptThread extends Thread{ private BluetoothServerSocket serverSocket; public AcceptThread(boolean secure){ BluetoothServerSocket temp = null; try { temp = mBluetoothAdapter.listenUsingRfcommWithServiceRecord( NAME_INSECURE, MY_UUID); } catch (IOException e) { Log.e("app", "listen() failed", e); } serverSocket = temp; } public void run(){ BluetoothSocket socket=null; while(true){ try { socket = serverSocket.accept(); } catch (IOException e) { Log.e("app", "accept() failed", e); break; } } if(socket!=null){ //此时可以新建一个数据交换线程,把此socket传进去 } } //取消监听 public void cancel(){ try { serverSocket.close(); } catch (IOException e) { Log.e("app", "Socket Type" + socketType + "close() of server failed", e); } } }
搜索到设备后可以获取设备的地址,通过此地址获取一个BluetoothDeviced对象,可以看做客户端,通过此对象device.createRfcommSocketToServiceRecord(MY_UUID);同一个UUID可与服务器建立连接获取另一个socket对象,由此服务端与客户端各有一个socket对象,此时 他们可以互相交换数据了。 创立客户端socket可建立线程
Java代码
- //另一个设备去连接本机,相当于客户端
- private class ConnectThread extends Thread{
- private BluetoothSocket socket;
- private BluetoothDevice device;
- public ConnectThread(BluetoothDevice device,boolean secure){
- this.device = device;
- BluetoothSocket tmp = null;
- try {
- tmp = device.createRfcommSocketToServiceRecord(MY_UUID_SECURE);
- } catch (IOException e) {
- Log.e("app", "create() failed", e);
- }
- }
- public void run(){
- mBluetoothAdapter.cancelDiscovery(); //取消设备查找
- try {
- socket.connect();
- } catch (IOException e) {
- try {
- socket.close();
- } catch (IOException e1) {
- Log.e("app", "unable to close() "+
- " socket during connection failure", e1);
- }
- connetionFailed(); //连接失败
- return;
- }
- //此时可以新建一个数据交换线程,把此socket传进去
- }
- public void cancel() {
- try {
- socket.close();
- } catch (IOException e) {
- Log.e("app", "close() of connect socket failed", e);
- }
- }
- }
//另一个设备去连接本机,相当于客户端 private class ConnectThread extends Thread{ private BluetoothSocket socket; private BluetoothDevice device; public ConnectThread(BluetoothDevice device,boolean secure){ this.device = device; BluetoothSocket tmp = null; try { tmp = device.createRfcommSocketToServiceRecord(MY_UUID_SECURE); } catch (IOException e) { Log.e("app", "create() failed", e); } } public void run(){ mBluetoothAdapter.cancelDiscovery(); //取消设备查找 try { socket.connect(); } catch (IOException e) { try { socket.close(); } catch (IOException e1) { Log.e("app", "unable to close() "+ " socket during connection failure", e1); } connetionFailed(); //连接失败 return; } //此时可以新建一个数据交换线程,把此socket传进去 } public void cancel() { try { socket.close(); } catch (IOException e) { Log.e("app", "close() of connect socket failed", e); } } }
5.建立数据通信线程,进行读取数据
Java代码
- //建立连接后,进行数据通信的线程
- private class ConnectedThread extends Thread{
- private BluetoothSocket socket;
- private InputStream inStream;
- private OutputStream outStream;
- public ConnectedThread(BluetoothSocket socket){
- this.socket = socket;
- try {
- //获得输入输出流
- inStream = socket.getInputStream();
- outStream = socket.getOutputStream();
- } catch (IOException e) {
- Log.e("app", "temp sockets not created", e);
- }
- }
- public void run(){
- byte[] buff = new byte[1024];
- int len=0;
- //读数据需不断监听,写不需要
- while(true){
- try {
- len = inStream.read(buff);
- //把读取到的数据发送给UI进行显示
- Message msg = handler.obtainMessage(BluetoothChat.MESSAGE_READ,
- len, -1, buff);
- msg.sendToTarget();
- } catch (IOException e) {
- Log.e("app", "disconnected", e);
- connectionLost(); //失去连接
- start(); //重新启动服务器
- break;
- }
- }
- }
- public void write(byte[] buffer) {
- try {
- outStream.write(buffer);
- // Share the sent message back to the UI Activity
- handler.obtainMessage(BluetoothChat.MESSAGE_WRITE, -1, -1, buffer)
- .sendToTarget();
- } catch (IOException e) {
- Log.e("app", "Exception during write", e);
- }
- }
- public void cancel() {
- try {
- socket.close();
- } catch (IOException e) {
- Log.e("app", "close() of connect socket failed", e);
- }
- }
- }
//建立连接后,进行数据通信的线程 private class ConnectedThread extends Thread{ private BluetoothSocket socket; private InputStream inStream; private OutputStream outStream; public ConnectedThread(BluetoothSocket socket){ this.socket = socket; try { //获得输入输出流 inStream = socket.getInputStream(); outStream = socket.getOutputStream(); } catch (IOException e) { Log.e("app", "temp sockets not created", e); } } public void run(){ byte[] buff = new byte[1024]; int len=0; //读数据需不断监听,写不需要 while(true){ try { len = inStream.read(buff); //把读取到的数据发送给UI进行显示 Message msg = handler.obtainMessage(BluetoothChat.MESSAGE_READ, len, -1, buff); msg.sendToTarget(); } catch (IOException e) { Log.e("app", "disconnected", e); connectionLost(); //失去连接 start(); //重新启动服务器 break; } } } public void write(byte[] buffer) { try { outStream.write(buffer); // Share the sent message back to the UI Activity handler.obtainMessage(BluetoothChat.MESSAGE_WRITE, -1, -1, buffer) .sendToTarget(); } catch (IOException e) { Log.e("app", "Exception during write", e); } } public void cancel() { try { socket.close(); } catch (IOException e) { Log.e("app", "close() of connect socket failed", e); } } }
到这里,蓝牙通信的基本操作已经全部完成。
转自:http://zhouyunan2010.iteye.com/blog/1186021