Android提高第十三篇之探秘蓝牙隐藏API

本文来自http://blog.csdn.net/hellogv/ ，引用必须注明出处！

       上次讲解Android的蓝牙基本用法，这次讲得深入些，探讨下蓝牙方面的隐藏API。用过Android系统设置(Setting)的人都知道蓝牙搜索之后可以建立配对和解除配对，但是这两项功能的函数没有在SDK中给出，那么如何去使用这两项功能呢？本文利用JAVA的反射机制去调用这两项功能对应的函数：createBond和removeBond，具体的发掘和实现步骤如下：

1.使用Git工具下载platform/packages/apps/Settings.git，在Setting源码中查找关于建立配对和解除配对的API，知道这两个API的宿主(BluetoothDevice)；

2.使用反射机制对BluetoothDevice枚举其所有方法和常量，看看是否存在:

 

 static public void printAllInform(Class clsShow) {
     try {
         // 取得所有方法
         Method[] hideMethod = clsShow.getMethods();
         int i = 0;
         for (; i < hideMethod.length; i++) {
             Log.e("method name", hideMethod[i].getName());
         }
         // 取得所有常量
         Field[] allFields = clsShow.getFields();
         for (i = 0; i < allFields.length; i++) {
             Log.e("Field name", allFields[i].getName());
         }
     } catch (SecurityException e) {
         // throw new RuntimeException(e.getMessage());
         e.printStackTrace();
     } catch (IllegalArgumentException e) {
         // throw new RuntimeException(e.getMessage());
         e.printStackTrace();
     } catch (Exception e) {
         // TODO Auto-generated catch block
         e.printStackTrace();
     }
 }

  

结果如下：

11-29 09:19:12.012: method name(452): cancelBondProcess
11-29 09:19:12.020: method name(452): cancelPairingUserInput
11-29 09:19:12.020: method name(452): createBond
11-29 09:19:12.020: method name(452): createInsecureRfcommSocket
11-29 09:19:12.027: method name(452): createRfcommSocket
11-29 09:19:12.027: method name(452): createRfcommSocketToServiceRecord
11-29 09:19:12.027: method name(452): createScoSocket
11-29 09:19:12.027: method name(452): describeContents
11-29 09:19:12.035: method name(452): equals
11-29 09:19:12.035: method name(452): fetchUuidsWithSdp
11-29 09:19:12.035: method name(452): getAddress
11-29 09:19:12.035: method name(452): getBluetoothClass
11-29 09:19:12.043: method name(452): getBondState
11-29 09:19:12.043: method name(452): getName
11-29 09:19:12.043: method name(452): getServiceChannel
11-29 09:19:12.043: method name(452): getTrustState
11-29 09:19:12.043: method name(452): getUuids
11-29 09:19:12.043: method name(452): hashCode
11-29 09:19:12.043: method name(452): isBluetoothDock
11-29 09:19:12.043: method name(452): removeBond
11-29 09:19:12.043: method name(452): setPairingConfirmation
11-29 09:19:12.043: method name(452): setPasskey
11-29 09:19:12.043: method name(452): setPin
11-29 09:19:12.043: method name(452): setTrust
11-29 09:19:12.043: method name(452): toString
11-29 09:19:12.043: method name(452): writeToParcel
11-29 09:19:12.043: method name(452): convertPinToBytes
11-29 09:19:12.043: method name(452): getClass
11-29 09:19:12.043: method name(452): notify
11-29 09:19:12.043: method name(452): notifyAll
11-29 09:19:12.043: method name(452): wait
11-29 09:19:12.051: method name(452): wait
11-29 09:19:12.051: method name(452): wait

 

3.如果枚举发现API存在(SDK却隐藏)，则自己实现调用方法：

 /**
  * 与设备配对 参考源码：platform/packages/apps/Settings.git
  * /Settings/src/com/android/settings/bluetooth/CachedBluetoothDevice.java
  */
 static public boolean createBond(Class btClass,BluetoothDevice btDevice) throws Exception {
     Method createBondMethod = btClass.getMethod("createBond");
     Boolean returnValue = (Boolean) createBondMethod.invoke(btDevice);
     return returnValue.booleanValue();
 }

 /**
  * 与设备解除配对 参考源码：platform/packages/apps/Settings.git
  * /Settings/src/com/android/settings/bluetooth/CachedBluetoothDevice.java
  */
 static public boolean removeBond(Class btClass,BluetoothDevice btDevice) throws Exception {
     Method removeBondMethod = btClass.getMethod("removeBond");
     Boolean returnValue = (Boolean) removeBondMethod.invoke(btDevice);
     return returnValue.booleanValue();
 }

PS:SDK之所以不给出隐藏的API肯定有其原因，也许是出于安全性或者是后续版本兼容性的考虑，因此不能保证隐藏API能在所有Android平台上很好地运行。。。

本文程序运行效果如下：

main.xml源码如下：

 <?xml version="1.0" encoding="utf-8"?>
 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
     android:orientation="vertical" android:layout_width="fill_parent"
     android:layout_height="fill_parent">
     <LinearLayout android:id="@+id/LinearLayout01"
         android:layout_height="wrap_content" android:layout_width="fill_parent">
         <Button android:layout_height="wrap_content" android:id="@+id/btnSearch"
             android:text="Search" android:layout_width="160dip"></Button>
         <Button android:layout_height="wrap_content"
             android:layout_width="160dip" android:text="Show" android:id="@+id/btnShow"></Button>
     </LinearLayout>
     <LinearLayout android:id="@+id/LinearLayout02"
         android:layout_width="wrap_content" android:layout_height="wrap_content"></LinearLayout>
     <ListView android:id="@+id/ListView01" android:layout_width="fill_parent"
         android:layout_height="fill_parent">
     </ListView>
 </LinearLayout>

工具类ClsUtils.java源码如下：

 package com.testReflect;

 import java.lang.reflect.Field;
 import java.lang.reflect.Method;

 import android.bluetooth.BluetoothDevice;
 import android.util.Log;

 public class ClsUtils {

     /**
      * 与设备配对 参考源码：platform/packages/apps/Settings.git
      * /Settings/src/com/android/settings/bluetooth/CachedBluetoothDevice.java
      */
     static public boolean createBond(Class btClass,BluetoothDevice btDevice) throws Exception {
         Method createBondMethod = btClass.getMethod("createBond");
         Boolean returnValue = (Boolean) createBondMethod.invoke(btDevice);
         return returnValue.booleanValue();
     }

     /**
      * 与设备解除配对 参考源码：platform/packages/apps/Settings.git
      * /Settings/src/com/android/settings/bluetooth/CachedBluetoothDevice.java
      */
     static public boolean removeBond(Class btClass,BluetoothDevice btDevice) throws Exception {
         Method removeBondMethod = btClass.getMethod("removeBond");
         Boolean returnValue = (Boolean) removeBondMethod.invoke(btDevice);
         return returnValue.booleanValue();
     }

     /**
      *
      * @param clsShow
      */
     static public void printAllInform(Class clsShow) {
         try {
             // 取得所有方法
             Method[] hideMethod = clsShow.getMethods();
             int i = 0;
             for (; i < hideMethod.length; i++) {
                 Log.e("method name", hideMethod[i].getName());
             }
             // 取得所有常量
             Field[] allFields = clsShow.getFields();
             for (i = 0; i < allFields.length; i++) {
                 Log.e("Field name", allFields[i].getName());
             }
         } catch (SecurityException e) {
             // throw new RuntimeException(e.getMessage());
             e.printStackTrace();
         } catch (IllegalArgumentException e) {
             // throw new RuntimeException(e.getMessage());
             e.printStackTrace();
         } catch (Exception e) {
             // TODO Auto-generated catch block
             e.printStackTrace();
         }
     }
 }

主程序testReflect.java的源码如下：

 package com.testReflect;

 import java.util.ArrayList;
 import java.util.List;
 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.util.Log;
 import android.view.View;
 import android.widget.AdapterView;
 import android.widget.ArrayAdapter;
 import android.widget.Button;
 import android.widget.ListView;
 import android.widget.Toast;

 public class testReflect extends Activity {
     Button btnSearch, btnShow;
     ListView lvBTDevices;
     ArrayAdapter<String> adtDevices;
     List<String> lstDevices = new ArrayList<String>();
     BluetoothDevice btDevice;
     BluetoothAdapter btAdapt;

     @Override
     public void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.main);

         btnSearch = (Button) this.findViewById(R.id.btnSearch);
         btnSearch.setOnClickListener(new ClickEvent());
         btnShow = (Button) this.findViewById(R.id.btnShow);
         btnShow.setOnClickListener(new ClickEvent());

         lvBTDevices = (ListView) this.findViewById(R.id.ListView01);
         adtDevices = new ArrayAdapter<String>(testReflect.this,
                 android.R.layout.simple_list_item_1, lstDevices);
         lvBTDevices.setAdapter(adtDevices);
         lvBTDevices.setOnItemClickListener(new ItemClickEvent());

         btAdapt = BluetoothAdapter.getDefaultAdapter();// 初始化本机蓝牙功能
         if (btAdapt.getState() == BluetoothAdapter.STATE_OFF)// 开蓝牙
             btAdapt.enable();

         // 注册Receiver来获取蓝牙设备相关的结果
         IntentFilter intent = new IntentFilter();
         intent.addAction(BluetoothDevice.ACTION_FOUND);
         intent.addAction(BluetoothDevice.ACTION_BOND_STATE_CHANGED);
         registerReceiver(searchDevices, intent);

     }


     private BroadcastReceiver searchDevices = new BroadcastReceiver() {
         public void onReceive(Context context, Intent intent) {
             String action = intent.getAction();
             Bundle b = intent.getExtras();
             Object[] lstName = b.keySet().toArray();

             // 显示所有收到的消息及其细节
             for (int i = 0; i < lstName.length; i++) {
                 String keyName = lstName[i].toString();
                 Log.e(keyName, String.valueOf(b.get(keyName)));
             }
             // 搜索设备时，取得设备的MAC地址
             if (BluetoothDevice.ACTION_FOUND.equals(action)) {
                 BluetoothDevice device = intent
                         .getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);

                 if (device.getBondState() == BluetoothDevice.BOND_NONE) {
                     String str = "未配对|" + device.getName() + "|" + device.getAddress();
                     lstDevices.add(str); // 获取设备名称和mac地址
                     adtDevices.notifyDataSetChanged();
                 }
             }
         }
     };

     class ItemClickEvent implements AdapterView.OnItemClickListener {

         @Override
         public void onItemClick(AdapterView<?> arg0, View arg1, int arg2,
                 long arg3) {
             btAdapt.cancelDiscovery();
             String str = lstDevices.get(arg2);
             String[] values = str.split("//|");
             String address=values[2];

             btDevice = btAdapt.getRemoteDevice(address);
             try {
                 if(values[0].equals("未配对"))
                 {
                     Toast.makeText(testReflect.this, "由未配对转为已配对", 500).show();
                     ClsUtils.createBond(btDevice.getClass(), btDevice);
                 }
                 else if(values[0].equals("已配对"))
                 {
                     Toast.makeText(testReflect.this, "由已配对转为未配对", 500).show();
                     ClsUtils.removeBond(btDevice.getClass(), btDevice);
                 }
             } catch (Exception e) {
                 // TODO Auto-generated catch block
                 e.printStackTrace();
             }
         }

     }

     /**
      * 按键处理
      * @author GV
      *
      */
     class ClickEvent implements View.OnClickListener {

         @Override
         public void onClick(View v) {
             if (v == btnSearch) {//搜索附近的蓝牙设备
                 lstDevices.clear();

                 Object[] lstDevice = btAdapt.getBondedDevices().toArray();
                 for (int i = 0; i < lstDevice.length; i++) {
                     BluetoothDevice device=(BluetoothDevice)lstDevice[i];
                     String str = "已配对|" + device.getName() + "|" + device.getAddress();
                     lstDevices.add(str); // 获取设备名称和mac地址
                     adtDevices.notifyDataSetChanged();
                 }
                 // 开始搜索
                 setTitle("本机蓝牙地址：" + btAdapt.getAddress());
                 btAdapt.startDiscovery();
             }
             else if(v==btnShow){//显示BluetoothDevice的所有方法和常量，包括隐藏API
                 ClsUtils.printAllInform(btDevice.getClass());
             }

         }

     }


 }