Android Bluetooth 学习（2）应用层实现蓝牙设备查找、tcp_ip通信

Bluetooth结构

    1、JAVA层
    frameworks/base/core/java/android/bluetooth/

   包含了bluetooth的JAVA类。

    2、JNI层

    frameworks/base/core/jni/android_bluetooth_开头的文件

   
   定义了bluez通过JNI到上层的接口。

   frameworks/base/core/jni/android_server_bluetoothservice.cpp

   调用硬件适配层的接口system/bluetooth/bluedroid/bluetooth.c

    3、bluez库

    external/bluez/

    
   这是bluez用户空间的库，开源的bluetooth代码，包括很多协议，生成libbluetooth.so。

    
    4、硬件适配层

    system/bluetooth/bluedroid/bluetooth.c

  
   包含了对硬件操作的接口

   system/bluetooth/data/*

   一些配置文件，复制到/etc/bluetooth/。

   还有其他一些测试代码和工具。

一、简略介绍Bluetooth开发使用到的类

1、BluetoothAdapter，蓝牙适配器，可判断蓝牙设备是否可用等功能。
常用方法列举如下：
    cancelDiscovery() ，取消搜索过程，在进行蓝牙设备搜索时，如果调用该方法会停止搜索。（搜索过程会持续12秒）
    disable()关闭蓝牙，也就是我们常说的禁用蓝牙。
    enable()打开蓝牙，这个方法打开蓝牙但不会弹出提示，正常流程操作下，我们会让系统提示用户是否打开蓝牙设备。如下两行代码可轻松搞定。

    Intent enabler=new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
    startActivityForResult(enabler,reCode);//同startActivity(enabler);（在主Activity启动一个二级Activity,reCode一般等于3，一定记得要在AndroidManifest.xml里面添加蓝牙权限）
    getAddress()获取本地蓝牙地址
    getDefaultAdapter()获取默认BluetoothAdapter，实际上，也只有这一种方法获取BluetoothAdapter
    getName()获取本地蓝牙名称
    getRemoteDevice(String address)根据蓝牙地址获取远程蓝牙设备
    getState()获取本地蓝牙适配器当前状态（感觉可能调试的时候更需要）
    isDiscovering()判断当前是否正在查找设备，是返回true
    isEnabled()判断蓝牙是否打开，已打开返回true，否则，返回false
    listenUsingRfcommWithServiceRecord(String name,UUID uuid)根据名称，UUID创建并返回    
    BluetoothServerSocket，这是创建BluetoothSocket服务器端的第一步
    startDiscovery()开始搜索，这是搜索的第一步

 2.BluetoothDevice看名字就知道，这个类描述了一个蓝牙设备
    createRfcommSocketToServiceRecord(UUIDuuid)根据UUID创建并返回一个BluetoothSocket
    这个方法也是我们获取BluetoothDevice的目的——创建BluetoothSocket
    这个类其他的方法，如getAddress(),getName(),同BluetoothAdapter
    这个类有几个隐藏方法，涉及到蓝牙的自动配对，setPin,createBond,cancelPairingUserInput,等方法（需要通过java的反射，调用这几个隐藏方法）

3.BluetoothServerSocket如果去除了Bluetooth相信大家一定再熟悉不过了，既然是Socket，方法就应该都差不多，
    这个类一种只有三个方法
    两个重载的accept(),accept(inttimeout)两者的区别在于后面的方法指定了过时时间，需要注意的是，执行这两个方法的时候，直到接收到了客户端的请求（或是过期之后），都会阻塞线程，应该放在新线程里运行！
    还有一点需要注意的是，这两个方法都返回一个BluetoothSocket，最后的连接也是服务器端与客户端的两个BluetoothSocket的连接
    close()关闭！

4.BluetoothSocket,跟BluetoothServerSocket相对，是客户端
    一共5个方法，不出意外，都会用到
    close(),关闭
    connect()连接
    getInptuStream()获取输入流
    getOutputStream()获取输出流
    getRemoteDevice()获取远程设备，这里指的是获取bluetoothSocket指定连接的那个远程蓝牙设备

二、蓝牙设备的发现、查找。

1.基于安全性考虑，设置开启可被搜索后，Android系统会默认给出120秒的时间，其他设备能在这120秒内搜索到它。  
    Intent enable = new Intent(BluetoothAdapter.ACTION_REQUEST_DISCOVERABLE); 
    startActivityForResult(enalbe,REQUEST_DISCOVERABLE); 
2.搜索蓝牙设备 

    BluetoothAdapter _bluetooth = BluetoothAdapter.getDefaultAdapter();
    _bluetooth.startDiscovery();
3.关闭蓝牙设备
    BluetoothAdapter _bluetooth = BluetoothAdapter.getDefaultAdapter();
    _bluetooth.disable();
4.创建蓝牙客户端
    BluetoothSocket socket = device.createRfcommSocketToServiceRecord(UUID.fromString(UUID号));
    socket.connect();
4.创建蓝牙服务端
    BluetoothServerSocket _serverSocket = _bluetooth.listenUsingRfcommWithServiceRecord(服务端名称,UUID.fromeString(UUID号));
    BluetoothSocket socket = _serverSocket.accept();
    InputStream inputStream = socket.getInputStream();
三、相关代码实现
注：tcp_ip模块需要在系统setting模块中，完成蓝牙的配对，只有配对成功的，才能进行socket通信（具体如何配对和如何自动配对，将在bluetoot3或者4中进行讲解）
AndridManifest.xml

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< manifest xmlns:android = "http://schemas.android.com/apk/res/android"      package = "com.example.thecaseforbluetooth"      android:versionCode = "1"      android:versionName = "1.0" >        < uses-sdk          android:minSdkVersion = "8"          android:targetSdkVersion = "15" /> < uses-permission android:name = "android.permission.BLUETOOTH_ADMIN" /> < uses-permission android:name = "android.permission.BLUETOOTH" />      < application          android:icon = "@drawable/ic_launcher"          android:label = "@string/app_name"          android:theme = "@style/AppTheme" >          < activity              android:name = ".BluetoothActivity"              android:label = "@string/title_activity_bluetooth" >              < intent-filter >                  < action android:name = "android.intent.action.MAIN" />                    < category android:name = "android.intent.category.LAUNCHER" />              </ intent-filter >          </ activity >      </ application >   </ manifest >

main.xml 

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< LinearLayout xmlns:android = "http://schemas.android.com/apk/res/android"      xmlns:tools = "http://schemas.android.com/tools"      android:id = "@+id/LinearLayout1"      android:layout_width = "match_parent"      android:layout_height = "match_parent"      android:orientation = "vertical" >      < Button    android:layout_width = "wrap_content"    android:layout_height = "wrap_content"    android:id = "@+id/btnSearch"    android:text = "查找设备" /> < Button    android:layout_width = "wrap_content"    android:layout_height = "wrap_content"    android:id = "@+id/btnExit"    android:text = "退出应用" /> < Button    android:layout_width = "wrap_content"    android:layout_height = "wrap_content"    android:id = "@+id/btnDis"    android:text = "设置可被发现" /> < Button    android:layout_width = "wrap_content"    android:layout_height = "wrap_content"    android:id = "@+id/btnserver"    android:text = "启动服务端" /> < ToggleButton android:layout_width = "wrap_content"    android:layout_height = "wrap_content"    android:id = "@+id/tbtnSwitch"    android:text = "开/关 蓝牙设备" /> < ListView    android:layout_width = "fill_parent"    android:layout_height = "wrap_content"    android:id = "@+id/lvDevices"     /> </ LinearLayout >

BluetoothActivity.java 

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package com.example.thecaseforbluetooth;   import java.util.ArrayList; import java.util.Set;   import android.app.Activity; import android.bluetooth.BluetoothAdapter; import android.bluetooth.BluetoothDevice; import android.content.BroadcastReceiver; import android.content.Context; import android.content.Intent; import android.content.IntentFilter; import android.os.Bundle; import android.view.Menu; import android.view.View; import android.view.View.OnClickListener; import android.widget.AdapterView; import android.widget.AdapterView.OnItemClickListener; import android.widget.ArrayAdapter; import android.widget.Button; import android.widget.ListView; import android.widget.Toast; import android.widget.ToggleButton;   public class BluetoothActivity extends Activity {      public Button searchBtn; //搜索蓝牙设备      public Button exitBtn; //退出应用      public Button discoverBtn; //设置可被发现      public ToggleButton openBtn; //开关蓝牙设备      public Button serverbtn;      public ListView listView; //蓝牙设备清单      public ArrayAdapter<String> adapter;      public ArrayList<String> list = new ArrayList<String>();      private BluetoothAdapter bluetoothAdapter = BluetoothAdapter.getDefaultAdapter();      Set<BluetoothDevice> bondDevices ;      public Context context ;      @Override      public void onCreate(Bundle savedInstanceState) {          super .onCreate(savedInstanceState);          setContentView(R.layout.main);          searchBtn = (Button)findViewById(R.id.btnSearch);          exitBtn = (Button)findViewById(R.id.btnExit);          discoverBtn = (Button)findViewById(R.id.btnDis);          openBtn = (ToggleButton)findViewById(R.id.tbtnSwitch);          serverbtn = (Button)findViewById(R.id.btnserver);          listView = (ListView)findViewById(R.id.lvDevices);          context = getApplicationContext();          adapter = new ArrayAdapter<String>( this , android.R.layout.simple_list_item_1,list);          listView.setAdapter(adapter);          openBtn.setChecked( false );          //注册广播接收信号          IntentFilter intent = new IntentFilter();          intent.addAction(BluetoothDevice.ACTION_FOUND); // 用BroadcastReceiver来取得搜索结果          intent.addAction(BluetoothAdapter.ACTION_SCAN_MODE_CHANGED); //每当扫描模式变化的时候，应用程序可以为通过ACTION_SCAN_MODE_CHANGED值来监听全局的消息通知。比如，当设备停止被搜寻以后，该消息可以被系统通知給应用程序。          intent.addAction(BluetoothAdapter.ACTION_STATE_CHANGED); //每当蓝牙模块被打开或者关闭，应用程序可以为通过ACTION_STATE_CHANGED值来监听全局的消息通知。          registerReceiver(searchReceiver, intent);          //显示已配对设备以及搜索未配对设备          searchBtn.setOnClickListener( new OnClickListener() {              @Override              public void onClick(View v) {                  // TODO Auto-generated method stub                  if (bluetoothAdapter.isDiscovering()){                      bluetoothAdapter.cancelDiscovery();                  }                  list.clear();                  bondDevices = bluetoothAdapter.getBondedDevices();                                    for (BluetoothDevice device : bondDevices) {                      String str = "  已配对完成   " + device.getName() + " "                      + device.getAddress();                      list.add(str);                      adapter.notifyDataSetChanged();                  }                  bluetoothAdapter.startDiscovery();              }          });          //退出应用          exitBtn.setOnClickListener( new OnClickListener() {                            @Override              public void onClick(View v) {                  // TODO Auto-generated method stub                  BluetoothActivity. this .finish();              }          });          //设置蓝牙设备可发现          discoverBtn.setOnClickListener( new OnClickListener() {                            @Override              public void onClick(View v) {                  // TODO Auto-generated method stub                  Intent discoverIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_DISCOVERABLE);                  discoverIntent.putExtra(BluetoothAdapter.EXTRA_DISCOVERABLE_DURATION, 300 );                  startActivity(discoverIntent);              }          });          //开关蓝牙设备          openBtn.setOnClickListener( new OnClickListener() {                            @Override              public void onClick(View v) {                  // TODO Auto-generated method stub                  if (openBtn.isChecked() == true ){                      bluetoothAdapter.disable();                  }                  else if (openBtn.isChecked() == false ){                      bluetoothAdapter.enable();                  }              }          });          //作为服务端开启          serverbtn.setOnClickListener( new OnClickListener() {                            @Override              public void onClick(View v) {                  // TODO Auto-generated method stub                  ServerThread serverThread = new ServerThread(bluetoothAdapter, context);                  Toast.makeText(context, "server 端启动" , 5000 ).show();                  serverThread.start();              }          });          listView.setOnItemClickListener( new ItemClickListener());      }      @Override      public void onStart() {          super .onStart();          // If BT is not on, request that it be enabled.          if (bluetoothAdapter == null ){              Toast.makeText(context, "蓝牙设备不可用" , 5000 ).show();          }           if (!bluetoothAdapter.isEnabled()) {              Intent enableIntent = new Intent(                      BluetoothAdapter.ACTION_REQUEST_ENABLE);              startActivityForResult(enableIntent, 3 );          }                 }      @Override      public boolean onCreateOptionsMenu(Menu menu) {          getMenuInflater().inflate(R.menu.main, menu);          return true ;      }            private final BroadcastReceiver searchReceiver = new BroadcastReceiver() {                    @Override          public void onReceive(Context context, Intent intent) {              // TODO Auto-generated method stub               String action = intent.getAction();               BluetoothDevice device = null ;               if (BluetoothDevice.ACTION_FOUND.equals(action)){                   device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);                   if (device.getBondState() == BluetoothDevice.BOND_NONE) {                   Toast.makeText(context, device.getName()+ "" , 5000 ).show();                   String str = " 未配对完成   " + device.getName() + " "                   + device.getAddress();                   if (list.indexOf(str) == - 1 ) // 防止重复添加                       list.add(str);                   }                   adapter.notifyDataSetChanged();               }                        }      };        public class ItemClickListener implements OnItemClickListener {            @Override          public void onItemClick(AdapterView<?> arg0, View arg1, int arg2,                  long arg3) {              // TODO Auto-generated method stub               if (bluetoothAdapter.isDiscovering())                   bluetoothAdapter.cancelDiscovery();               String str = list.get(arg2);               String address = str.substring(str.length() - 17 );               BluetoothDevice btDev = bluetoothAdapter.getRemoteDevice(address);               ClientThread clientThread = new ClientThread(btDev, context);               clientThread.start();          }} }

Bluetoothprotocol.java 

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package com.example.thecaseforbluetooth;   public interface Bluetoothprotocol {      public static final String PROTOCOL_SCHEME_L2CAP = "btl2cap" ;      public static final String PROTOCOL_SCHEME_RFCOMM = "btspp" ;      public static final String PROTOCOL_SCHEME_BT_OBEX = "btgoep" ;      public static final String PROTOCOL_SCHEME_TCP_OBEX = "tcpobex" ; }

ServerThread.java 

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package com.example.thecaseforbluetooth;   import java.io.IOException; import java.io.InputStream; import java.io.OutputStream; import java.util.UUID;   import android.bluetooth.BluetoothAdapter; import android.bluetooth.BluetoothServerSocket; import android.bluetooth.BluetoothSocket; import android.content.Context; import android.os.Message; import android.util.Log; import android.widget.Toast;   public class ServerThread extends Thread {      public BluetoothServerSocket mserverSocket;      public BluetoothAdapter bluetoothAdapter;      public BluetoothSocket socket;      public Context context;      public ServerThread(BluetoothAdapter bluetoothAdapter,Context context) {          this .bluetoothAdapter = bluetoothAdapter;          this .context = context;      }        public void run() {                    try {              /* 创建一个蓝牙服务器               * 参数分别：服务器名称、UUID   */              mserverSocket = bluetoothAdapter.listenUsingRfcommWithServiceRecord(Bluetoothprotocol.PROTOCOL_SCHEME_RFCOMM,                      UUID.fromString( "00001101-0000-1000-8000-00805F9B34FB" ));       //          /* 接受客户端的连接请求 */              socket = mserverSocket.accept();              //下面代码作者偷懒，读写另外起一个线程最好              //接收数据               byte [] buffer = new byte [ 1024 ];                  int bytes;                  InputStream mmInStream = null ;                                    try {                      mmInStream = socket.getInputStream();                  } catch (IOException e1) {                      // TODO Auto-generated catch block                      e1.printStackTrace();                  }                    System.out.println( "zhoulc server" );                  while ( true ){                       if ( (bytes = mmInStream.read(buffer)) > 0 )                          {                              byte [] buf_data = new byte [bytes];                              for ( int i= 0 ; i<bytes; i++)                              {                                  buf_data[i] = buffer[i];                              }                              String s = new String(buf_data);                              System.out.println(s+ "zhoulc server is in" );                  }                   }          } catch (Exception e) {              // TODO Auto-generated catch block              e.printStackTrace();          }   }       }

ClientThread.java 

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package com.example.thecaseforbluetooth;   import java.io.IOException; import java.io.OutputStream; import java.util.UUID;   import android.bluetooth.BluetoothDevice; import android.bluetooth.BluetoothSocket; import android.content.Context; import android.widget.Toast;   public class ClientThread extends Thread {      public BluetoothSocket socket;      public BluetoothDevice device;      public Context context;      public ClientThread(BluetoothDevice device,Context context){          this .device = device;          this .context = context;      }      public void run() {          try {              //创建一个Socket连接：只需要服务器在注册时的UUID号              socket = device.createRfcommSocketToServiceRecord(UUID.fromString( "00001101-0000-1000-8000-00805F9B34FB" ));              //连接              socket.connect();              //下面代码作者偷懒，读写另外起一个线程最好              //发送数据              if (socket == null )              {                  Toast.makeText(context, "链接失败" , 5000 ).show();                  return ;              }              System.out.println( "zhoulc client" );              while ( true ){                  try {                      System.out.println( "zhoulc client is in" );                      String msg = "hello everybody I am client" ;                      OutputStream os = socket.getOutputStream();                      os.write(msg.getBytes());                  } catch (IOException e) {                      // TODO Auto-generated catch block                      e.printStackTrace();                  }                        }          }          catch (IOException e)          {              e.printStackTrace();          }      } }