Android Bluetooth 學習（2）應用層實現藍牙設備查找、tcp_ip通訊

Bluetooth結構

    一、JAVA層
    frameworks/base/core/java/android/bluetooth/

   包含了bluetooth的JAVA類。

    二、JNI層

    frameworks/base/core/jni/android_bluetooth_開頭的文件

   
   定義了bluez經過JNI到上層的接口。

   frameworks/base/core/jni/android_server_bluetoothservice.cpp

   調用硬件適配層的接口system/bluetooth/bluedroid/bluetooth.c

    三、bluez庫

    external/bluez/

    
   這是bluez用戶空間的庫，開源的bluetooth代碼，包括不少協議，生成libbluetooth.so。

    
    四、硬件適配層

    system/bluetooth/bluedroid/bluetooth.c

  
   包含了對硬件操做的接口

   system/bluetooth/data/*

   一些配置文件，複製到/etc/bluetooth/。

   還有其餘一些測試代碼和工具。

1、簡略介紹Bluetooth開發使用到的類

一、BluetoothAdapter，藍牙適配器，可判斷藍牙設備是否可用等功能。
經常使用方法列舉以下：
    cancelDiscovery() ，取消搜索過程，在進行藍牙設備搜索時，若是調用該方法會中止搜索。（搜索過程會持續12秒）
    disable()關閉藍牙，也就是咱們常說的禁用藍牙。
    enable()打開藍牙，這個方法打開藍牙但不會彈出提示，正常流程操做下，咱們會讓系統提示用戶是否打開藍牙設備。以下兩行代碼可輕鬆搞定。

    Intent enabler=new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
    startActivityForResult(enabler,reCode);//同startActivity(enabler);（在主Activity啓動一個二級Activity,reCode通常等於3，必定記得要在AndroidManifest.xml裏面添加藍牙權限）
    getAddress()獲取本地藍牙地址
    getDefaultAdapter()獲取默認BluetoothAdapter，實際上，也只有這一種方法獲取BluetoothAdapter
    getName()獲取本地藍牙名稱
    getRemoteDevice(String address)根據藍牙地址獲取遠程藍牙設備
    getState()獲取本地藍牙適配器當前狀態（感受可能調試的時候更須要）
    isDiscovering()判斷當前是否正在查找設備，是返回true
    isEnabled()判斷藍牙是否打開，已打開返回true，不然，返回false
    listenUsingRfcommWithServiceRecord(String name,UUID uuid)根據名稱，UUID建立並返回    
    BluetoothServerSocket，這是建立BluetoothSocket服務器端的第一步
    startDiscovery()開始搜索，這是搜索的第一步

 2.BluetoothDevice看名字就知道，這個類描述了一個藍牙設備
    createRfcommSocketToServiceRecord(UUIDuuid)根據UUID建立並返回一個BluetoothSocket
    這個方法也是咱們獲取BluetoothDevice的目的——建立BluetoothSocket
    這個類其餘的方法，如getAddress(),getName(),同BluetoothAdapter
    這個類有幾個隱藏方法，涉及到藍牙的自動配對，setPin,createBond,cancelPairingUserInput,等方法（須要經過java的反射，調用這幾個隱藏方法）

3.BluetoothServerSocket若是去除了Bluetooth相信你們必定再熟悉不過了，既然是Socket，方法就應該都差很少，
    這個類一種只有三個方法
    兩個重載的accept(),accept(inttimeout)二者的區別在於後面的方法指定了過期時間，須要注意的是，執行這兩個方法的時候，直到接收到了客戶端的請求（或是過時以後），都會阻塞線程，應該放在新線程裏運行！
    還有一點須要注意的是，這兩個方法都返回一個BluetoothSocket，最後的鏈接也是服務器端與客戶端的兩個BluetoothSocket的鏈接
    close()關閉！

4.BluetoothSocket,跟BluetoothServerSocket相對，是客戶端
    一共5個方法，不出意外，都會用到
    close(),關閉
    connect()鏈接
    getInptuStream()獲取輸入流
    getOutputStream()獲取輸出流
    getRemoteDevice()獲取遠程設備，這裏指的是獲取bluetoothSocket指定鏈接的那個遠程藍牙設備

2、藍牙設備的發現、查找。

1.基於安全性考慮，設置開啓可被搜索後，Android系統會默認給出120秒的時間，其餘設備能在這120秒內搜索到它。
    Intent enable = new Intent(BluetoothAdapter.ACTION_REQUEST_DISCOVERABLE);
    startActivityForResult(enalbe,REQUEST_DISCOVERABLE);
2.搜索藍牙設備

    BluetoothAdapter _bluetooth = BluetoothAdapter.getDefaultAdapter();
    _bluetooth.startDiscovery();
3.關閉藍牙設備
    BluetoothAdapter _bluetooth = BluetoothAdapter.getDefaultAdapter();
    _bluetooth.disable();
4.建立藍牙客戶端
    BluetoothSocket socket = device.createRfcommSocketToServiceRecord(UUID.fromString(UUID號));
    socket.connect();
4.建立藍牙服務端
    BluetoothServerSocket _serverSocket = _bluetooth.listenUsingRfcommWithServiceRecord(服務端名稱,UUID.fromeString(UUID號));
    BluetoothSocket socket = _serverSocket.accept();
    InputStream inputStream = socket.getInputStream();
3、相關代碼實現
注：tcp_ip模塊須要在系統setting模塊中，完成藍牙的配對，只有配對成功的，才能進行socket通訊（具體如何配對和如何自動配對，將在bluetoot3或者4中進行講解）
AndridManifest.xml

<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

<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="查找設備"
/>
<Button
  android:layout_width="wrap_content"
  android:layout_height="wrap_content"
  android:id="@+id/btnExit"
  android:text="退出應用"
/>
<Button
  android:layout_width="wrap_content"
  android:layout_height="wrap_content"
  android:id="@+id/btnDis"
  android:text="設置可被發現"
/>
<Button
  android:layout_width="wrap_content"
  android:layout_height="wrap_content"
  android:id="@+id/btnserver"
  android:text="啓動服務端"
/>
<ToggleButton
android:layout_width="wrap_content"
  android:layout_height="wrap_content"
  android:id="@+id/tbtnSwitch"
  android:text="開/關 藍牙設備"
/>
<ListView
  android:layout_width="fill_parent"
  android:layout_height="wrap_content"
  android:id="@+id/lvDevices"
  
/>
</LinearLayout>

BluetoothActivity.java

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;//搜索藍牙設備
	public Button exitBtn;//退出應用
	public Button discoverBtn;//設置可被發現
	public ToggleButton openBtn;//開關藍牙設備
	public Button serverbtn;
	public ListView listView;//藍牙設備清單
	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);
        //註冊廣播接收信號
        IntentFilter intent = new IntentFilter(); 
        intent.addAction(BluetoothDevice.ACTION_FOUND);// 用BroadcastReceiver來取得搜索結果 
        intent.addAction(BluetoothAdapter.ACTION_SCAN_MODE_CHANGED); //每當掃描模式變化的時候，應用程序能夠爲經過ACTION_SCAN_MODE_CHANGED值來監聽全局的消息通知。好比，當設備中止被搜尋之後，該消息能夠被系統通知給應用程序。
        intent.addAction(BluetoothAdapter.ACTION_STATE_CHANGED); //每當藍牙模塊被打開或者關閉，應用程序能夠爲經過ACTION_STATE_CHANGED值來監聽全局的消息通知。
        registerReceiver(searchReceiver, intent); 
        //顯示已配對設備以及搜索未配對設備
        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 = "	已配對完成	" + device.getName() +"	" 
                    + device.getAddress(); 
					list.add(str);
					adapter.notifyDataSetChanged();
				}
				bluetoothAdapter.startDiscovery();
			}
		});
        //退出應用
        exitBtn.setOnClickListener(new OnClickListener() {
			
			@Override
			public void onClick(View v) {
				// TODO Auto-generated method stub
				BluetoothActivity.this.finish();
			}
		});
        //設置藍牙設備可發現
        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);
			}
		});
        //開關藍牙設備
        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();
				}
			}
		});
        //做爲服務端開啓
        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 端啓動", 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, "藍牙設備不可用", 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 = "	未配對完成	" + device.getName() +"	" 
                 + device.getAddress(); 
				 if (list.indexOf(str) == -1)// 防止重複添加 
                     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

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

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 {
			/* 建立一個藍牙服務器 
			 * 參數分別：服務器名稱、UUID	 */	
			mserverSocket = bluetoothAdapter.listenUsingRfcommWithServiceRecord(Bluetoothprotocol.PROTOCOL_SCHEME_RFCOMM,
					UUID.fromString("00001101-0000-1000-8000-00805F9B34FB"));		
//			/* 接受客戶端的鏈接請求 */
			socket = mserverSocket.accept();
			//下面代碼做者偷懶，讀寫另外起一個線程最好
			//接收數據
			 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

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 {
			//建立一個Socket鏈接：只須要服務器在註冊時的UUID號
			socket = device.createRfcommSocketToServiceRecord(UUID.fromString("00001101-0000-1000-8000-00805F9B34FB"));
			//鏈接
			socket.connect();
			//下面代碼做者偷懶，讀寫另外起一個線程最好
			//發送數據
			if (socket == null) 
			{
				Toast.makeText(context, "連接失敗", 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();
		} 
	}
}