发送ble广播 聊天 源码

发送BLE广播聊天的源码示例如下：

import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothGattCharacteristic;
import android.bluetooth.BluetoothGattService;
import android.content.Context;
import android.os.Bundle;
import android.os.Handler;
import android.os.Looper;
import android.os.Message;
import java.util.ArrayList;
import java.util.List;
import java.util.UUID;

public class ChatService {
    private Context mContext;
    private BluetoothAdapter mBluetoothAdapter;
    
    private Handler mHandler = new Handler(Looper.getMainLooper()) {
        @Override
        public void handleMessage(Message msg) {
            switch (msg.what) {
                case MESSAGE_READ:
                    byte[] buffer = (byte[]) msg.obj;
                    String message = new String(buffer, 0, msg.arg1);
                    // 处理接收到的消息
                    break;
            }
        }
    };
    
    public ChatService(Context context) {
        mContext = context;
        mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
    }
    
    public void startAdvertising() {
        BluetoothGattService gattService = new BluetoothGattService(
            UUID.fromString("0000xxxx-0000-1000-8000-00805F9B34FB"),
            BluetoothGattService.SERVICE_TYPE_PRIMARY);
            
        BluetoothGattCharacteristic characteristic = new BluetoothGattCharacteristic(
            UUID.fromString("0000yyyy-0000-1000-8000-00805F9B34FB"),
            BluetoothGattCharacteristic.PROPERTY_READ | BluetoothGattCharacteristic.PROPERTY_WRITE,
            BluetoothGattCharacteristic.PERMISSION_READ | BluetoothGattCharacteristic.PERMISSION_WRITE);
        gattService.addCharacteristic(characteristic);
        
        List<BluetoothGattService> gattServices = new ArrayList<>();
        gattServices.add(gattService);
        
        mBluetoothAdapter.getBluetoothLeAdvertiser().startAdvertising(
            createAdvertiseSettings(true),
            createAdvertiseData(gattServices),
            mAdvertiseCallback);
    }
    
    private AdvertiseCallback mAdvertiseCallback = new AdvertiseCallback() {
        @Override
        public void onStartSuccess(AdvertiseSettings settingsInEffect) {
            // 广播开始成功
        }

        @Override
        public void onStartFailure(int errorCode) {
            // 广播开始失败
        }
    };
    
    private AdvertiseSettings createAdvertiseSettings(boolean connectable) {
        AdvertiseSettings.Builder builder = new AdvertiseSettings.Builder();
        builder.setAdvertiseMode(AdvertiseSettings.ADVERTISE_MODE_BALANCED);
        builder.setConnectable(connectable);
        builder.setTimeout(0);
        builder.setTxPowerLevel(AdvertiseSettings.ADVERTISE_TX_POWER_MEDIUM);
        return builder.build();
    }
    
    private AdvertiseData createAdvertiseData(List<BluetoothGattService> services) {
        AdvertiseData.Builder builder = new AdvertiseData.Builder();
        for (BluetoothGattService service : services) {
            builder.addServiceUuid(new ParcelUuid(service.getUuid()));
        }
        return builder.build();
    }
}

上述代码实现了手机作为BLE外设发送广播聊天功能。通过`startAdvertising()`方法开启广播，使用自定义的UUID创建Gatt服务和特征，并将其添加到广播数据中。当其他设备扫描并连接上该广播时，可以读取特定的Gatt特征，实现聊天功能。在`handleMessage()`方法中处理接收到的消息。