蓝牙模块服务查看

这里用到一个软件可以查看使用的蓝牙模块广播的服务，打开手机蓝牙后开启软件即可扫描到附近的蓝牙信号，找到自己的蓝牙模块名字，点击旁边的CONNECT按钮：

连接成功后就可以看到正在广播的服务，找到类似如下的描述：

上面的UUIDf000fff1-0451-4000-b000-000000000000到来进行写操作，描述Client Characteristic Configuration的UUID0x2902补充完整就是00002902-0000-1000-8000-00805f9b34fb是用来监听数据接收。这里有网友提供的UUID的解释，不同厂家的蓝牙模块UUID可能会不一样。这里的两个UUID在后面编写程序的时候会用到。

测试代码

为使工程简洁，就不创建别的类了，所有代码就都在MainActivity里面来写，代码量也不大。

新建工程

新建一个Android空白工程，使用的是Android Studio，具体新建步骤就不描述了：

添加权限

<!-- 蓝牙权限 -->    <uses-permission android:name="android.permission.BLUETOOTH" />    <uses-permission android:name="android.permission.BLUETOOTH_ADMIN" />    <!-- 定位权限 -->    <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />

初始化几个工具控件

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:tools="http://schemas.android.com/tools"    android:layout_width="match_parent"    android:layout_height="match_parent"    android:orientation="vertical"    tools:context=".MainActivity">    <LinearLayout        android:layout_width="match_parent"        android:layout_height="wrap_content"        android:orientation="horizontal">        <Button            android:id="@+id/scan_btn"            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:layout_weight="1"            android:text="扫描" />        <Button            android:id="@+id/send_btn"            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:layout_weight="1"            android:text="发送" />    </LinearLayout>    <TextView        android:id="@+id/re_tv"        android:layout_width="match_parent"        android:layout_height="wrap_content" />    <ListView        android:id="@+id/bluetooth_lv"        android:layout_width="match_parent"        android:layout_height="wrap_content"></ListView></LinearLayout>

代码流程

蓝牙的操作流程网友介绍得比较详细，这里不再做重复介绍，上面的演示效果除了布局，写的代码其余都在这一个MainActivity类里，也就没有做太多优化（抄起来方便），其中比较关键的就是一定要检查那两个UUID：

package com.example.bluetooth4;import android.bluetooth.BluetoothAdapter;import android.bluetooth.BluetoothDevice;import android.bluetooth.BluetoothGatt;import android.bluetooth.BluetoothGattCallback;import android.bluetooth.BluetoothGattCharacteristic;import android.bluetooth.BluetoothGattDescriptor;import android.bluetooth.BluetoothGattService;import android.bluetooth.BluetoothProfile;import android.bluetooth.le.BluetoothLeScanner;import android.bluetooth.le.ScanCallback;import android.bluetooth.le.ScanResult;import android.os.Build;import android.os.Handler;import android.os.Message;import android.support.annotation.RequiresApi;import android.support.v7.app.AppCompatActivity;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.TextView;import android.widget.Toast;import java.util.ArrayList;import java.util.LinkedList;import java.util.List;import java.util.UUID;public class MainActivity extends AppCompatActivity implements View.OnClickListener {    // 布局控件    private Button scanBtn;    private Button sendBtn;    private TextView reTv;    // 蓝牙相关的变量    private BluetoothAdapter mBluetoothAdapter;    private BluetoothLeScanner mBluetoothManager;    private List<BluetoothDevice> mBluetoothDevice;    private BluetoothGatt mBluetoothGatt;    private BluetoothGattCharacteristic mWriteCharacteristic;    // 用于显示搜索到的蓝牙列表    private ArrayAdapter arrayAdapter;    private ListView bluetoothLv;    private LinkedList<String> bluetoothList =  new LinkedList();    @RequiresApi(api = Build.VERSION_CODES.LOLLIPOP)    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        // 初始化控件        scanBtn = findViewById(R.id.scan_btn);        sendBtn = findViewById(R.id.send_btn);        bluetoothLv = findViewById(R.id.bluetooth_lv);        reTv =  findViewById(R.id.re_tv);        // 设置监听事件        scanBtn.setOnClickListener(this);        sendBtn.setOnClickListener(this);        mBluetoothDevice = new ArrayList<>();        arrayAdapter = new ArrayAdapter(this, android.R.layout.simple_list_item_1, bluetoothList);        bluetoothLv.setAdapter(arrayAdapter);        bluetoothLv.setOnItemClickListener(new AdapterView.OnItemClickListener() {            @Override            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {                Log.d("Bluetooth", "选择的蓝牙名称：" +mBluetoothDevice.get(position).getName());                mBluetoothGatt = mBluetoothAdapter.getRemoteDevice(mBluetoothDevice.get(position).getAddress()).connectGatt(getApplicationContext(), true, mGattCallback);                Message msg = new Message();                msg.obj = "正在连接...";                mHandlerLog.sendMessage(msg);            }        });        // 直接获取手机蓝牙是配置，没有再写判断蓝牙的状态（用软件之前那先把蓝牙打开）        mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();        mBluetoothManager = mBluetoothAdapter.getBluetoothLeScanner();    }    // 刷新蓝牙列表    private Handler mHandler = new Handler(){        @Override        public void handleMessage(Message msg) {            super.handleMessage(msg);            BluetoothDevice device = (BluetoothDevice)msg.obj;            Log.d("Bluetooth", "蓝牙名称：" + device.getAddress()+"  "+device.getName());            String temp = device.getAddress()+"  "+device.getName();            if(bluetoothList.contains(temp)==false) {                mBluetoothDevice.add(device);                bluetoothList.add(temp);                arrayAdapter.notifyDataSetChanged();            }        }    };    // 提示连接状态    private Handler mHandlerLog = new Handler(){        @Override        public void handleMessage(Message msg) {            super.handleMessage(msg);            Toast.makeText(MainActivity.this, (String)msg.obj, Toast.LENGTH_SHORT).show();        }    };    // 用来刷新接收控件    private Handler mHandlerRes = new Handler(){        @Override        public void handleMessage(Message msg) {            super.handleMessage(msg);            reTv.setText((String)msg.obj);        }    };    // 扫描蓝牙的回调，把扫描到的用mHandler刷新到界面上    private ScanCallback scanCallback = new ScanCallback() {        @Override        public void onScanResult(int callbackType, ScanResult result) {            BluetoothDevice device = result.getDevice();            Message msg = new Message();            msg.obj = device;            mHandler.sendMessage(msg);        }    };    // 两个按钮的点击事件    @RequiresApi(api = Build.VERSION_CODES.LOLLIPOP)    @Override    public void onClick(View v) {        if(v.getId()==R.id.scan_btn) {            if(scanBtn.getText().toString().equals("扫描"))            {                mBluetoothDevice.clear();                scanBtn.setText("停止");                mBluetoothManager.startScan(scanCallback);            }            else            {                scanBtn.setText("扫描");                mBluetoothManager.stopScan(scanCallback);            }        }        if(v.getId()==R.id.send_btn) {            mWriteCharacteristic.setValue("bluetest");            Log.d("Bluetooth", "发送数据");            mBluetoothGatt.writeCharacteristic(mWriteCharacteristic);        }    }    // 蓝牙的服务回调    private BluetoothGattCallback mGattCallback = new BluetoothGattCallback() {        @RequiresApi(api = Build.VERSION_CODES.JELLY_BEAN_MR2)        @Override        public void onConnectionStateChange(BluetoothGatt gatt, int status, int newState) {            super.onConnectionStateChange(gatt, status, newState);            if (newState == BluetoothProfile.STATE_CONNECTED) { //连接成功                Log.d("Bluetooth", "连接成功");                Message msg = new Message();                msg.obj = "连接成功";                mHandlerLog.sendMessage(msg);                mBluetoothGatt.discoverServices(); //连接成功后就去找出该设备中的服务 private BluetoothGatt mBluetoothGatt;            } else if (newState == BluetoothProfile.STATE_DISCONNECTED) {  //连接失败            }        }        @RequiresApi(api = Build.VERSION_CODES.JELLY_BEAN_MR2)        @Override        public void onServicesDiscovered(BluetoothGatt gatt, int status) {            if (status == BluetoothGatt.GATT_SUCCESS) {   //找到服务了                List<BluetoothGattService> serviceList= mBluetoothGatt.getServices();                //在这里可以对服务进行解析，寻找到你需要的服务                Log.d("Bluetooth", "找到服务了"+serviceList.size());                for(int i=0;i<serviceList.size();i++)                {                    Log.d("Bluetooth", "服务:"+serviceList.get(i).getUuid().toString());                    List<BluetoothGattCharacteristic> gattCharacteristics = serviceList.get(i).getCharacteristics();                    for (BluetoothGattCharacteristic gattCharacteristic : gattCharacteristics) { // 遍历每条服务里的所有Characteristic                        Log.d("Bluetooth", "服务Characteristic:"+gattCharacteristic.getUuid().toString());                        if (gattCharacteristic.getUuid().toString().equals("f000fff1-0451-4000-b000-000000000000")) {                            mBluetoothGatt.setCharacteristicNotification(gattCharacteristic,true);                            //获取一个描述符                            BluetoothGattDescriptor descriptor = gattCharacteristic.getDescriptor(UUID.fromString("00002902-0000-1000-8000-00805f9b34fb"));                            descriptor.setValue(BluetoothGattDescriptor.ENABLE_NOTIFICATION_VALUE);                            mBluetoothGatt.readCharacteristic(gattCharacteristic);                            mBluetoothGatt.writeDescriptor(descriptor);                            mWriteCharacteristic = gattCharacteristic;                        }                    }                }            } else {                Log.d("Bluetooth", "onServicesDiscovered received: " + status);            }        }        @Override        public void onCharacteristicRead(BluetoothGatt gatt, BluetoothGattCharacteristic characteristic, int status) {            if (status == BluetoothGatt.GATT_SUCCESS) {            }        }        @Override        public void onCharacteristicWrite(BluetoothGatt gatt, BluetoothGattCharacteristic characteristic, int status) {            Log.d("Bluetooth", "onDescriptorWriteonDescriptorWrite = " + status + ", descriptor =" + characteristic.getUuid().toString());        }//有数据过来就会回调到这个方法        @Override        public void onCharacteristicChanged(BluetoothGatt gatt, BluetoothGattCharacteristic characteristic) {            Log.d("Bluetooth", "接收数据:"+ characteristic.getStringValue(0));            if (characteristic.getValue() != null) {                Message msg = new Message();                msg.obj = characteristic.getStringValue(0);                mHandlerRes.sendMessage(msg);            }        }        @Override        public void onDescriptorWrite(BluetoothGatt gatt, BluetoothGattDescriptor descriptor, int status) {            Log.d("Bluetooth", "--------onDescriptorWrite-----");        }        @Override        public void onReadRemoteRssi(BluetoothGatt gatt, int rssi, int status) {            Log.d("Bluetooth", "--------onReadRemoteRssi-----"+rssi);        }    };}

提供demo以作参考

Android(安卓)BLE蓝牙4.2数据透传操作

BLE蓝牙4.2数据透传操作