Example usage for io.netty.buffer ByteBuf readUnsignedShortLE

List of usage examples for io.netty.buffer ByteBuf readUnsignedShortLE

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Introduction

In this page you can find the example usage for io.netty.buffer ByteBuf readUnsignedShortLE.

Prototype

public abstract int readUnsignedShortLE();

Source Link

Document

Gets an unsigned 16-bit short integer at the current readerIndex in the Little Endian Byte Order and increases the readerIndex by 2 in this buffer.

Usage

From source file:org.traccar.protocol.NavigilProtocolDecoder.java

License:Apache License

private Position parseUnitReport(DeviceSession deviceSession, ByteBuf buf, int sequenceNumber) {
    Position position = new Position(getProtocolName());

    position.setValid(true);/*from   w w  w . j a  v  a 2  s.  co m*/
    position.set(Position.KEY_INDEX, sequenceNumber);
    position.setDeviceId(deviceSession.getDeviceId());

    buf.readUnsignedShortLE(); // report trigger
    position.set(Position.KEY_FLAGS, buf.readUnsignedShortLE());

    position.setLatitude(buf.readIntLE() * 0.0000001);
    position.setLongitude(buf.readIntLE() * 0.0000001);
    position.setAltitude(buf.readUnsignedShortLE());

    position.set(Position.KEY_SATELLITES, buf.readUnsignedShortLE());
    position.set(Position.KEY_SATELLITES_VISIBLE, buf.readUnsignedShortLE());
    position.set("gpsAntennaState", buf.readUnsignedShortLE());

    position.setSpeed(buf.readUnsignedShortLE() * 0.194384);
    position.setCourse(buf.readUnsignedShortLE());

    position.set(Position.KEY_ODOMETER, buf.readUnsignedIntLE());
    position.set(Position.KEY_DISTANCE, buf.readUnsignedIntLE());

    position.set(Position.KEY_BATTERY, buf.readUnsignedShortLE() * 0.001);

    position.set(Position.KEY_CHARGE, buf.readUnsignedShortLE());

    position.setTime(convertTimestamp(buf.readUnsignedIntLE()));

    return position;
}

From source file:org.traccar.protocol.NavigilProtocolDecoder.java

License:Apache License

private Position parseTg2Report(DeviceSession deviceSession, ByteBuf buf, int sequenceNumber) {
    Position position = new Position(getProtocolName());

    position.setValid(true);//w ww  . ja v a 2  s .co m
    position.set(Position.KEY_INDEX, sequenceNumber);
    position.setDeviceId(deviceSession.getDeviceId());

    buf.readUnsignedShortLE(); // report trigger
    buf.readUnsignedByte(); // reserved
    buf.readUnsignedByte(); // assisted GPS age

    position.setTime(convertTimestamp(buf.readUnsignedIntLE()));

    position.setLatitude(buf.readIntLE() * 0.0000001);
    position.setLongitude(buf.readIntLE() * 0.0000001);
    position.setAltitude(buf.readUnsignedShortLE());

    position.set(Position.KEY_SATELLITES, buf.readUnsignedByte());
    position.set(Position.KEY_SATELLITES_VISIBLE, buf.readUnsignedByte());

    position.setSpeed(buf.readUnsignedShortLE() * 0.194384);
    position.setCourse(buf.readUnsignedShortLE());

    position.set(Position.KEY_ODOMETER, buf.readUnsignedIntLE());
    position.set("maximumSpeed", buf.readUnsignedShortLE());
    position.set("minimumSpeed", buf.readUnsignedShortLE());

    position.set(Position.PREFIX_IO + 1, buf.readUnsignedShortLE()); // VSAUT1 voltage
    position.set(Position.PREFIX_IO + 2, buf.readUnsignedShortLE()); // VSAUT2 voltage
    position.set(Position.PREFIX_IO + 3, buf.readUnsignedShortLE()); // solar voltage

    position.set(Position.KEY_BATTERY, buf.readUnsignedShortLE() * 0.001);

    return position;
}

From source file:org.traccar.protocol.NavigilProtocolDecoder.java

License:Apache License

private Position parseSnapshot4(DeviceSession deviceSession, ByteBuf buf, int sequenceNumber) {
    Position position = new Position(getProtocolName());

    position.set(Position.KEY_INDEX, sequenceNumber);
    position.setDeviceId(deviceSession.getDeviceId());

    buf.readUnsignedByte(); // report trigger
    buf.readUnsignedByte(); // position fix source
    buf.readUnsignedByte(); // GNSS fix quality
    buf.readUnsignedByte(); // GNSS assistance age

    long flags = buf.readUnsignedIntLE();
    position.setValid((flags & 0x0400) == 0x0400);

    position.setTime(convertTimestamp(buf.readUnsignedIntLE()));

    position.setLatitude(buf.readIntLE() * 0.0000001);
    position.setLongitude(buf.readIntLE() * 0.0000001);
    position.setAltitude(buf.readUnsignedShortLE());

    position.set(Position.KEY_SATELLITES, buf.readUnsignedByte());
    position.set(Position.KEY_SATELLITES_VISIBLE, buf.readUnsignedByte());

    position.setSpeed(buf.readUnsignedShortLE() * 0.194384);
    position.setCourse(buf.readUnsignedShortLE() * 0.1);

    position.set("maximumSpeed", buf.readUnsignedByte());
    position.set("minimumSpeed", buf.readUnsignedByte());
    position.set(Position.KEY_ODOMETER, buf.readUnsignedIntLE());

    position.set(Position.PREFIX_IO + 1, buf.readUnsignedByte()); // supply voltage 1
    position.set(Position.PREFIX_IO + 2, buf.readUnsignedByte()); // supply voltage 2
    position.set(Position.KEY_BATTERY, buf.readUnsignedShortLE() * 0.001);

    return position;
}

From source file:org.traccar.protocol.NavigilProtocolDecoder.java

License:Apache License

private Position parseTrackingData(DeviceSession deviceSession, ByteBuf buf, int sequenceNumber,
        long timestamp) {
    Position position = new Position(getProtocolName());

    position.set(Position.KEY_INDEX, sequenceNumber);
    position.setDeviceId(deviceSession.getDeviceId());
    position.setTime(convertTimestamp(timestamp));

    buf.readUnsignedByte(); // tracking mode

    short flags = buf.readUnsignedByte();
    position.setValid((flags & 0x01) == 0x01);

    buf.readUnsignedShortLE(); // duration

    position.setLatitude(buf.readIntLE() * 0.0000001);
    position.setLongitude(buf.readIntLE() * 0.0000001);

    position.setSpeed(UnitsConverter.knotsFromKph(buf.readUnsignedByte()));
    position.setCourse(buf.readUnsignedByte() * 2.0);

    position.set(Position.KEY_SATELLITES, buf.readUnsignedByte());
    position.set(Position.KEY_BATTERY, buf.readUnsignedShortLE() * 0.001);
    position.set(Position.KEY_ODOMETER, buf.readUnsignedIntLE());

    return position;
}

From source file:org.traccar.protocol.NavigilProtocolDecoder.java

License:Apache License

@Override
protected Object decode(Channel channel, SocketAddress remoteAddress, Object msg) throws Exception {

    ByteBuf buf = (ByteBuf) msg;

    buf.readUnsignedByte(); // protocol version
    buf.readUnsignedByte(); // version id
    int sequenceNumber = buf.readUnsignedShortLE();
    int messageId = buf.readUnsignedShortLE();
    buf.readUnsignedShortLE(); // length
    int flags = buf.readUnsignedShortLE();
    buf.readUnsignedShortLE(); // checksum

    DeviceSession deviceSession = getDeviceSession(channel, remoteAddress,
            String.valueOf(buf.readUnsignedIntLE()));
    if (deviceSession == null) {
        return null;
    }//from  w w  w . ja v a  2s  .  c om

    long timestamp = buf.readUnsignedIntLE();

    if ((flags & 0x1) == 0x0) {
        sendAcknowledgment(channel, sequenceNumber);
    }

    switch (messageId) {
    case MSG_UNIT_REPORT:
        return parseUnitReport(deviceSession, buf, sequenceNumber);
    case MSG_TG2_REPORT:
        return parseTg2Report(deviceSession, buf, sequenceNumber);
    case MSG_POSITION_REPORT:
        return parsePositionReport(deviceSession, buf, sequenceNumber, timestamp);
    case MSG_POSITION_REPORT_2:
        return parsePositionReport2(deviceSession, buf, sequenceNumber, timestamp);
    case MSG_SNAPSHOT4:
        return parseSnapshot4(deviceSession, buf, sequenceNumber);
    case MSG_TRACKING_DATA:
        return parseTrackingData(deviceSession, buf, sequenceNumber, timestamp);
    default:
        return null;
    }
}

From source file:org.traccar.protocol.NavisProtocolDecoder.java

License:Apache License

private Position parseNtcbPosition(DeviceSession deviceSession, ByteBuf buf) {
    Position position = new Position(getProtocolName());

    position.setDeviceId(deviceSession.getDeviceId());

    int format;/* ww  w. j ava 2s  . c om*/
    if (buf.getUnsignedByte(buf.readerIndex()) == 0) {
        format = buf.readUnsignedShortLE();
    } else {
        format = buf.readUnsignedByte();
    }
    position.set("format", format);

    position.set(Position.KEY_INDEX, buf.readUnsignedIntLE());
    position.set(Position.KEY_EVENT, buf.readUnsignedShortLE());

    buf.skipBytes(6); // event time

    short armedStatus = buf.readUnsignedByte();
    if (isFormat(format, F10, F20, F30, F40, F50, F51, F52)) {
        position.set(Position.KEY_ARMED, BitUtil.to(armedStatus, 7));
        if (BitUtil.check(armedStatus, 7)) {
            position.set(Position.KEY_ALARM, Position.ALARM_GENERAL);
        }
    } else if (isFormat(format, F60)) {
        position.set(Position.KEY_ARMED, BitUtil.check(armedStatus, 0));
        if (BitUtil.check(armedStatus, 1)) {
            position.set(Position.KEY_ALARM, Position.ALARM_GENERAL);
        }
    }

    position.set(Position.KEY_STATUS, buf.readUnsignedByte());
    position.set(Position.KEY_RSSI, buf.readUnsignedByte());

    if (isFormat(format, F10, F20, F30)) {
        int output = buf.readUnsignedShortLE();
        position.set(Position.KEY_OUTPUT, output);
        for (int i = 0; i < 16; i++) {
            position.set(Position.PREFIX_OUT + (i + 1), BitUtil.check(output, i));
        }
    } else if (isFormat(format, F50, F51, F52)) {
        short extField = buf.readUnsignedByte();
        position.set(Position.KEY_OUTPUT, BitUtil.to(extField, 2));
        position.set(Position.PREFIX_OUT + 1, BitUtil.check(extField, 0));
        position.set(Position.PREFIX_OUT + 2, BitUtil.check(extField, 1));
        position.set(Position.KEY_SATELLITES, BitUtil.from(extField, 2));
    } else if (isFormat(format, F40, F60)) {
        short output = buf.readUnsignedByte();
        position.set(Position.KEY_OUTPUT, BitUtil.to(output, 4));
        for (int i = 0; i < 4; i++) {
            position.set(Position.PREFIX_OUT + (i + 1), BitUtil.check(output, i));
        }
    }

    if (isFormat(format, F10, F20, F30, F40)) {
        int input = buf.readUnsignedShortLE();
        position.set(Position.KEY_INPUT, input);
        if (!isFormat(format, F40)) {
            for (int i = 0; i < 16; i++) {
                position.set(Position.PREFIX_IN + (i + 1), BitUtil.check(input, i));
            }
        } else {
            position.set(Position.PREFIX_IN + 1, BitUtil.check(input, 0));
            position.set(Position.PREFIX_IN + 2, BitUtil.check(input, 1));
            position.set(Position.PREFIX_IN + 3, BitUtil.check(input, 2));
            position.set(Position.PREFIX_IN + 4, BitUtil.check(input, 3));
            position.set(Position.PREFIX_IN + 5, BitUtil.between(input, 4, 7));
            position.set(Position.PREFIX_IN + 6, BitUtil.between(input, 7, 10));
            position.set(Position.PREFIX_IN + 7, BitUtil.between(input, 10, 12));
            position.set(Position.PREFIX_IN + 8, BitUtil.between(input, 12, 14));
        }
    } else if (isFormat(format, F50, F51, F52, F60)) {
        short input = buf.readUnsignedByte();
        position.set(Position.KEY_INPUT, input);
        for (int i = 0; i < 8; i++) {
            position.set(Position.PREFIX_IN + (i + 1), BitUtil.check(input, i));
        }
    }

    position.set(Position.KEY_POWER, buf.readUnsignedShortLE() * 0.001);
    position.set(Position.KEY_BATTERY, buf.readUnsignedShortLE() * 0.001);

    if (isFormat(format, F10, F20, F30)) {
        position.set(Position.PREFIX_TEMP + 1, buf.readShortLE());
    }

    if (isFormat(format, F10, F20, F50, F51, F52, F60)) {
        position.set(Position.PREFIX_ADC + 1, buf.readUnsignedShortLE());
        position.set(Position.PREFIX_ADC + 2, buf.readUnsignedShortLE());
    }
    if (isFormat(format, F60)) {
        position.set(Position.PREFIX_ADC + 3, buf.readUnsignedShortLE());
    }

    // Impulse counters
    if (isFormat(format, F20, F50, F51, F52, F60)) {
        buf.readUnsignedIntLE();
        buf.readUnsignedIntLE();
    }

    if (isFormat(format, F60)) {
        // Fuel
        buf.readUnsignedShortLE();
        buf.readUnsignedShortLE();
        buf.readByte();
        buf.readShortLE();
        buf.readByte();
        buf.readUnsignedShortLE();
        buf.readByte();
        buf.readUnsignedShortLE();
        buf.readByte();
        buf.readUnsignedShortLE();
        buf.readByte();
        buf.readUnsignedShortLE();
        buf.readByte();
        buf.readUnsignedShortLE();
        buf.readByte();
        buf.readUnsignedShortLE();
        buf.readByte();
        buf.readUnsignedShortLE();

        position.set(Position.PREFIX_TEMP + 1, buf.readByte());
        position.set(Position.PREFIX_TEMP + 2, buf.readByte());
        position.set(Position.PREFIX_TEMP + 3, buf.readByte());
        position.set(Position.PREFIX_TEMP + 4, buf.readByte());
        position.set(Position.KEY_AXLE_WEIGHT, buf.readIntLE());
        position.set(Position.KEY_RPM, buf.readUnsignedShortLE());
    }

    if (isFormat(format, F20, F50, F51, F52, F60)) {
        int navSensorState = buf.readUnsignedByte();
        position.setValid(BitUtil.check(navSensorState, 1));
        if (isFormat(format, F60)) {
            position.set(Position.KEY_SATELLITES, BitUtil.from(navSensorState, 2));
        }

        DateBuilder dateBuilder = new DateBuilder()
                .setTime(buf.readUnsignedByte(), buf.readUnsignedByte(), buf.readUnsignedByte())
                .setDateReverse(buf.readUnsignedByte(), buf.readUnsignedByte() + 1, buf.readUnsignedByte());
        position.setTime(dateBuilder.getDate());

        if (isFormat(format, F60)) {
            position.setLatitude(buf.readIntLE() / 600000.0);
            position.setLongitude(buf.readIntLE() / 600000.0);
            position.setAltitude(buf.readIntLE() * 0.1);
        } else {
            position.setLatitude(buf.readFloatLE() / Math.PI * 180);
            position.setLongitude(buf.readFloatLE() / Math.PI * 180);
        }

        position.setSpeed(UnitsConverter.knotsFromKph(buf.readFloatLE()));
        position.setCourse(buf.readUnsignedShortLE());

        position.set(Position.KEY_ODOMETER, buf.readFloatLE() * 1000);
        position.set(Position.KEY_DISTANCE, buf.readFloatLE() * 1000);

        // Segment times
        buf.readUnsignedShortLE();
        buf.readUnsignedShortLE();
    }

    // Other
    if (isFormat(format, F51, F52)) {
        buf.readUnsignedShortLE();
        buf.readByte();
        buf.readUnsignedShortLE();
        buf.readUnsignedShortLE();
        buf.readByte();
        buf.readUnsignedShortLE();
        buf.readUnsignedShortLE();
        buf.readByte();
        buf.readUnsignedShortLE();
    }

    // Four temperature sensors
    if (isFormat(format, F40, F52)) {
        position.set(Position.PREFIX_TEMP + 1, buf.readByte());
        position.set(Position.PREFIX_TEMP + 2, buf.readByte());
        position.set(Position.PREFIX_TEMP + 3, buf.readByte());
        position.set(Position.PREFIX_TEMP + 4, buf.readByte());
    }

    return position;
}

From source file:org.traccar.protocol.NavisProtocolDecoder.java

License:Apache License

private Position parseFlexPosition(DeviceSession deviceSession, ByteBuf buf) {

    Position position = new Position(getProtocolName());

    position.setDeviceId(deviceSession.getDeviceId());

    int status = 0;
    short input = 0;
    short output = 0;

    for (int i = 0; i < flexBitFieldSize; i++) {
        if (!checkFlexBitfield(i)) {
            continue;
        }//  w ww  . java  2 s.c  om

        switch (i) {
        case 0:
            position.set(Position.KEY_INDEX, buf.readUnsignedIntLE());
            break;
        case 1:
            position.set(Position.KEY_EVENT, buf.readUnsignedShortLE());
            break;
        case 3:
            short armedStatus = buf.readUnsignedByte();
            position.set(Position.KEY_ARMED, BitUtil.check(armedStatus, 0));
            if (BitUtil.check(armedStatus, 1)) {
                position.set(Position.KEY_ALARM, Position.ALARM_GENERAL);
            }
            break;
        case 4:
            status = buf.readUnsignedByte();
            position.set(Position.KEY_STATUS, status);
            break;
        case 5:
            int status2 = buf.readUnsignedByte();
            position.set(Position.KEY_STATUS, (short) (BitUtil.to(status, 8) | (status2 << 8)));
            break;
        case 6:
            position.set(Position.KEY_RSSI, buf.readUnsignedByte());
            break;
        case 7:
            int navSensorState = buf.readUnsignedByte();
            position.setValid(BitUtil.check(navSensorState, 1));
            position.set(Position.KEY_SATELLITES, BitUtil.from(navSensorState, 2));
            break;
        case 8:
            position.setTime(new DateBuilder(new Date(buf.readUnsignedIntLE() * 1000)).getDate());
            break;
        case 9:
            position.setLatitude(buf.readIntLE() / 600000.0);
            break;
        case 10:
            position.setLongitude(buf.readIntLE() / 600000.0);
            break;
        case 11:
            position.setAltitude(buf.readIntLE() * 0.1);
            break;
        case 12:
            position.setSpeed(UnitsConverter.knotsFromKph(buf.readFloatLE()));
            break;
        case 13:
            position.setCourse(buf.readUnsignedShortLE());
            break;
        case 14:
            position.set(Position.KEY_ODOMETER, buf.readFloatLE() * 1000);
            break;
        case 15:
            position.set(Position.KEY_DISTANCE, buf.readFloatLE() * 1000);
            break;
        case 18:
            position.set(Position.KEY_POWER, buf.readUnsignedShortLE() * 0.001);
            break;
        case 19:
            position.set(Position.KEY_BATTERY, buf.readUnsignedShortLE() * 0.001);
            break;
        case 20:
        case 21:
        case 22:
        case 23:
        case 24:
        case 25:
        case 26:
        case 27:
            position.set(Position.PREFIX_ADC + (i - 19), buf.readUnsignedShortLE());
            break;
        case 28:
            input = buf.readUnsignedByte();
            position.set(Position.KEY_INPUT, input);
            for (int k = 0; k < 8; k++) {
                position.set(Position.PREFIX_IN + (k + 1), BitUtil.check(input, k));
            }
            break;
        case 29:
            short input2 = buf.readUnsignedByte();
            position.set(Position.KEY_INPUT, (short) (BitUtil.to(input, 8) | (input2 << 8)));
            for (int k = 0; k < 8; k++) {
                position.set(Position.PREFIX_IN + (k + 9), BitUtil.check(input2, k));
            }
            break;
        case 30:
            output = buf.readUnsignedByte();
            position.set(Position.KEY_OUTPUT, output);
            for (int k = 0; k < 8; k++) {
                position.set(Position.PREFIX_OUT + (k + 1), BitUtil.check(output, k));
            }
            break;
        case 31:
            short output2 = buf.readUnsignedByte();
            position.set(Position.KEY_OUTPUT, (short) (BitUtil.to(output, 8) | (output2 << 8)));
            for (int k = 0; k < 8; k++) {
                position.set(Position.PREFIX_OUT + (k + 9), BitUtil.check(output2, k));
            }
            break;
        case 36:
            position.set(Position.KEY_HOURS, buf.readUnsignedIntLE() * 1000);
            break;
        case 44:
        case 45:
        case 46:
        case 47:
        case 48:
        case 49:
        case 50:
        case 51:
            position.set(Position.PREFIX_TEMP + (i - 43), buf.readByte());
            break;
        case 68:
            position.set("can-speed", buf.readUnsignedByte());
            break;
        // FLEX 2.0
        case 69:
            int satVisible = 0;
            for (int k = 0; k < 8; k++) {
                satVisible += buf.readUnsignedByte();
            }
            position.set(Position.KEY_SATELLITES_VISIBLE, satVisible);
            break;
        case 70:
            position.set(Position.KEY_HDOP, buf.readUnsignedByte() * 0.1);
            position.set(Position.KEY_PDOP, buf.readUnsignedByte() * 0.1);
            break;
        default:
            if (i < FLEX_FIELDS_SIZES.length) {
                buf.skipBytes(FLEX_FIELDS_SIZES[i]);
            }
            break;
        }
    }

    return position;
}

From source file:org.traccar.protocol.NavisProtocolDecoder.java

License:Apache License

private Position parseFlex20Position(DeviceSession deviceSession, ByteBuf buf) {

    Position position = new Position(getProtocolName());
    position.setDeviceId(deviceSession.getDeviceId());

    int length = buf.readUnsignedShort();
    if (length <= buf.readableBytes() && buf.readUnsignedByte() == 0x0A) {

        buf.readUnsignedByte(); // length of static part

        position.set(Position.KEY_INDEX, buf.readUnsignedIntLE());

        position.set(Position.KEY_EVENT, buf.readUnsignedShortLE());
        buf.readUnsignedInt(); // event time

        int navSensorState = buf.readUnsignedByte();
        position.setValid(BitUtil.check(navSensorState, 1));
        position.set(Position.KEY_SATELLITES, BitUtil.from(navSensorState, 2));

        position.setTime(new DateBuilder(new Date(buf.readUnsignedIntLE() * 1000)).getDate());
        position.setLatitude(buf.readIntLE() / 600000.0);
        position.setLongitude(buf.readIntLE() / 600000.0);
        position.setAltitude(buf.readIntLE() * 0.1);
        position.setSpeed(UnitsConverter.knotsFromKph(buf.readFloatLE()));
        position.setCourse(buf.readUnsignedShortLE());
        position.set(Position.KEY_ODOMETER, buf.readFloatLE() * 1000);

        buf.skipBytes(length - buf.readerIndex() - 1); // skip unused part
    }//ww w  . j  a  v  a2s . com

    return position;
}

From source file:org.traccar.protocol.NavisProtocolDecoder.java

License:Apache License

private Object decodeNtcb(Channel channel, SocketAddress remoteAddress, ByteBuf buf) {

    prefix = buf.toString(buf.readerIndex(), 4, StandardCharsets.US_ASCII);
    buf.skipBytes(prefix.length()); // prefix @NTC by default
    serverId = buf.readUnsignedIntLE();//  w  w  w.  j  a va 2s  .  c om
    deviceUniqueId = buf.readUnsignedIntLE();
    int length = buf.readUnsignedShortLE();
    buf.skipBytes(2); // header and data XOR checksum

    if (length == 0) {
        return null; // keep alive message
    }

    String type = buf.toString(buf.readerIndex(), 3, StandardCharsets.US_ASCII);
    buf.skipBytes(type.length());

    if (type.equals("*>S")) {
        return processHandshake(channel, remoteAddress, buf);
    } else {
        DeviceSession deviceSession = getDeviceSession(channel, remoteAddress);
        if (deviceSession != null) {
            switch (type) {
            case "*>A":
                return processNtcbArray(deviceSession, channel, buf);
            case "*>T":
                return processNtcbSingle(deviceSession, channel, buf);
            case "*>F":
                buf.skipBytes(3);
                return processFlexNegotiation(channel, buf);
            default:
                break;
            }
        }
    }

    return null;
}

From source file:org.traccar.protocol.NoranProtocolDecoder.java

License:Apache License

@Override
protected Object decode(Channel channel, SocketAddress remoteAddress, Object msg) throws Exception {

    ByteBuf buf = (ByteBuf) msg;

    buf.readUnsignedShortLE(); // length
    int type = buf.readUnsignedShortLE();

    if (type == MSG_SHAKE_HAND && channel != null) {

        ByteBuf response = Unpooled.buffer(13);
        response.writeCharSequence("\r\n*KW", StandardCharsets.US_ASCII);
        response.writeByte(0);//w w w.  j  a  va 2 s  .  c  o  m
        response.writeShortLE(response.capacity());
        response.writeShortLE(MSG_SHAKE_HAND_RESPONSE);
        response.writeByte(1); // status
        response.writeCharSequence("\r\n", StandardCharsets.US_ASCII);

        channel.writeAndFlush(new NetworkMessage(response, remoteAddress));

    } else if (type == MSG_UPLOAD_POSITION || type == MSG_UPLOAD_POSITION_NEW || type == MSG_CONTROL_RESPONSE
            || type == MSG_ALARM) {

        boolean newFormat = false;
        if (type == MSG_UPLOAD_POSITION && buf.readableBytes() == 48
                || type == MSG_ALARM && buf.readableBytes() == 48
                || type == MSG_CONTROL_RESPONSE && buf.readableBytes() == 57) {
            newFormat = true;
        }

        Position position = new Position(getProtocolName());

        if (type == MSG_CONTROL_RESPONSE) {
            buf.readUnsignedIntLE(); // GIS ip
            buf.readUnsignedIntLE(); // GIS port
        }

        position.setValid(BitUtil.check(buf.readUnsignedByte(), 0));

        short alarm = buf.readUnsignedByte();
        switch (alarm) {
        case 1:
            position.set(Position.KEY_ALARM, Position.ALARM_SOS);
            break;
        case 2:
            position.set(Position.KEY_ALARM, Position.ALARM_OVERSPEED);
            break;
        case 3:
            position.set(Position.KEY_ALARM, Position.ALARM_GEOFENCE_EXIT);
            break;
        case 9:
            position.set(Position.KEY_ALARM, Position.ALARM_POWER_OFF);
            break;
        default:
            break;
        }

        if (newFormat) {
            position.setSpeed(UnitsConverter.knotsFromKph(buf.readUnsignedIntLE()));
            position.setCourse(buf.readFloatLE());
        } else {
            position.setSpeed(UnitsConverter.knotsFromKph(buf.readUnsignedByte()));
            position.setCourse(buf.readUnsignedShortLE());
        }
        position.setLongitude(buf.readFloatLE());
        position.setLatitude(buf.readFloatLE());

        if (!newFormat) {
            long timeValue = buf.readUnsignedIntLE();
            DateBuilder dateBuilder = new DateBuilder().setYear((int) BitUtil.from(timeValue, 26))
                    .setMonth((int) BitUtil.between(timeValue, 22, 26))
                    .setDay((int) BitUtil.between(timeValue, 17, 22))
                    .setHour((int) BitUtil.between(timeValue, 12, 17))
                    .setMinute((int) BitUtil.between(timeValue, 6, 12))
                    .setSecond((int) BitUtil.to(timeValue, 6));
            position.setTime(dateBuilder.getDate());
        }

        ByteBuf rawId;
        if (newFormat) {
            rawId = buf.readSlice(12);
        } else {
            rawId = buf.readSlice(11);
        }
        String id = rawId.toString(StandardCharsets.US_ASCII).replaceAll("[^\\p{Print}]", "");
        DeviceSession deviceSession = getDeviceSession(channel, remoteAddress, id);
        if (deviceSession == null) {
            return null;
        }
        position.setDeviceId(deviceSession.getDeviceId());

        if (newFormat) {
            DateFormat dateFormat = new SimpleDateFormat("yy-MM-dd HH:mm:ss");
            position.setTime(dateFormat.parse(buf.readSlice(17).toString(StandardCharsets.US_ASCII)));
            buf.readByte();
        }

        if (!newFormat) {
            position.set(Position.PREFIX_IO + 1, buf.readUnsignedByte());
            position.set(Position.KEY_FUEL_LEVEL, buf.readUnsignedByte());
        } else if (type == MSG_UPLOAD_POSITION_NEW) {
            position.set(Position.PREFIX_TEMP + 1, buf.readShortLE());
            position.set(Position.KEY_ODOMETER, buf.readFloatLE());
        }

        return position;
    }

    return null;
}