BLE扫描API BluetoothAdapter.startLeScan(ScanCallback)需要回调功能才能获得扫描结果.该方法需要如下所示：

private BluetoothAdapter.LeScanCallback ScanCallback =
        new BluetoothAdapter.LeScanCallback()onLeScan(final BluetoothDevice device,int RSSi,final byte[] scanRecord)
    {...}

scanRecord变量是一个包含广告数据包有效负载的字节数组.

根据BLE规范,有效载荷的结构非常简单如下：

数据包最长可达47个字节,包括：

> 1字节前导码
> 4字节访问地址
> 2-39字节广告channelPDU
> 3字节CRC

对于广告通信信道,访问地址始终为0x8E89BED6.

PDU又有自己的头(2个字节：有效载荷的大小及其类型 – 设备是否支持连接等)和实际有效载荷(最多37个字节).

最后,有效载荷的前6个字节是设备的MAC地址,实际信息最多可以有31个字节.

实际信息的格式如下：

第一个字节是数据的长度,第二个字节是类型,后跟数据.

这是一种聪明的方法,允许任何应用程序跳过整个数据记录,如果他们不关心内容.

以下是确定Advertisement数据包内容的示例代码：

parseAdvertisementPacket(final byte[] scanRecord) {

    byte[] advertisedData = Arrays.copyOf(scanRecord,scanRecord.length);

    int offset = 0;
    while (offset < (advertisedData.length - 2)) {
        int len = advertisedData[offset++];
        if (len == 0)
            break;

        int type = advertisedData[offset++];
        switch (type) {
            case 0x02: // Partial list of 16-bit UUIDs
            case 0x03: // Complete list of 16-bit UUIDs
                while (len > 1) {
                    int uuid16 = advertisedData[offset++] & 0xFF;
                    uuid16 |= (advertisedData[offset++] << 8);
                    len -= 2;
                    uuids.add(UUID.fromString(String.format(
                            "%08x-0000-1000-8000-00805f9b34fb",uuid16)));
                }
                break;
            case 0x06:// Partial list of 128-bit UUIDs
            case 0x07:// Complete list of 128-bit UUIDs
                // Loop through the advertised 128-bit UUID's.
                while (len >= 16) {
                    try {
                        // Wrap the advertised bits and order them.
                        ByteBuffer buffer = ByteBuffer.wrap(advertisedData,offset++,16).order(ByteOrder.LITTLE_ENDIAN);
                        long mostSignificantBit = buffer.getLong();
                        long leastSignificantBit = buffer.getLong();
                        uuids.add(new UUID(leastSignificantBit,mostSignificantBit));
                    } catch (IndexOutOfBoundsException e) {
                        // Defensive programming.
                        Log.e("BlueToothDeviceFilter.parseUUID",e.toString());
                        continue;
                    } finally {
                        // Move the offset to read the next uuid.
                        offset += 15;
                        len -= 16;
                    }
                }
                break;
            case 0xFF:  // Manufacturer Specific Data
                Log.d(TAG,"Manufacturer Specific Data size:" + len +" bytes" );
                while (len > 1) {
                    if(i < 32) {
                        MfgData[i++] = advertisedData[offset++];
                    }
                    len -= 1;
                }
                Log.d(TAG,"Manufacturer Specific Data saved." + MfgData.toString());
                break;
            default:
                offset += (len - 1);
                break;
        }
    }

谢谢

how-ibeacons-work

bluetooth org specs

mass让我朝着正确的方向前进！