@Override
protected Object decode(Channel channel, SocketAddress remoteAddress, Object msg)
throws Exception {
ChannelBuffer buf = (ChannelBuffer) msg;
buf.skipBytes(2); // header
int type = buf.readUnsignedByte();
buf.readUnsignedShort(); // size
if (type == MSG_ON_DEMAND
|| type == MSG_POSITION_UPLOAD
|| type == MSG_POSITION_REUPLOAD
|| type == MSG_ALARM
|| type == MSG_REPLY
|| type == MSG_PERIPHERAL) {
// Create new position
Position position = new Position();
position.setProtocol(getProtocolName());
// Device identification
if (!identify(readSerialNumber(buf), channel)) {
return null;
}
position.setDeviceId(getDeviceId());
// Date and time
Calendar time = Calendar.getInstance(TimeZone.getTimeZone("UTC"));
time.clear();
time.set(Calendar.YEAR, 2000 + ChannelBufferTools.readHexInteger(buf, 2));
time.set(Calendar.MONTH, ChannelBufferTools.readHexInteger(buf, 2) - 1);
time.set(Calendar.DAY_OF_MONTH, ChannelBufferTools.readHexInteger(buf, 2));
time.set(Calendar.HOUR_OF_DAY, ChannelBufferTools.readHexInteger(buf, 2));
time.set(Calendar.MINUTE, ChannelBufferTools.readHexInteger(buf, 2));
time.set(Calendar.SECOND, ChannelBufferTools.readHexInteger(buf, 2));
position.setTime(time.getTime());
// Location
position.setLatitude(ChannelBufferTools.readCoordinate(buf));
position.setLongitude(ChannelBufferTools.readCoordinate(buf));
position.setSpeed(UnitsConverter.knotsFromKph(ChannelBufferTools.readHexInteger(buf, 4)));
position.setCourse(ChannelBufferTools.readHexInteger(buf, 4));
// Flags
int flags = buf.readUnsignedByte();
position.setValid((flags & 0x80) != 0);
if (type == MSG_ALARM) {
buf.skipBytes(2);
} else {
// Odometer
position.set(Event.KEY_ODOMETER, buf.readUnsignedMedium());
// Status
buf.skipBytes(4);
// Other
buf.skipBytes(8);
}
// TODO: parse extra data
return position;
} else if (type == MSG_LOGIN && channel != null) {
buf.skipBytes(4); // serial number
buf.readByte(); // reserved
ChannelBuffer response = ChannelBuffers.dynamicBuffer();
response.writeByte(0x29);
response.writeByte(0x29); // header
response.writeByte(MSG_CONFIRMATION);
response.writeShort(5); // size
response.writeByte(buf.readUnsignedByte());
response.writeByte(type);
response.writeByte(0); // reserved
response.writeByte(Crc.xorChecksum(response.toByteBuffer()));
response.writeByte(0x0D); // ending
channel.write(response);
}
return null;
}
private Position decodeNormalMessage(
ChannelBuffer buf, Channel channel, SocketAddress remoteAddress) {
Position position = new Position();
position.setProtocol(getProtocolName());
buf.readByte(); // header
String id = String.valueOf(Long.parseLong(ChannelBuffers.hexDump(buf.readBytes(5))));
if (!identify(id, channel, remoteAddress)) {
return null;
}
position.setDeviceId(getDeviceId());
int version = ChannelBufferTools.readHexInteger(buf, 1);
buf.readUnsignedByte(); // type
buf.readBytes(2); // length
DateBuilder dateBuilder =
new DateBuilder()
.setDay(ChannelBufferTools.readHexInteger(buf, 2))
.setMonth(ChannelBufferTools.readHexInteger(buf, 2))
.setYear(ChannelBufferTools.readHexInteger(buf, 2))
.setHour(ChannelBufferTools.readHexInteger(buf, 2))
.setMinute(ChannelBufferTools.readHexInteger(buf, 2))
.setSecond(ChannelBufferTools.readHexInteger(buf, 2));
position.setTime(dateBuilder.getDate());
double latitude = convertCoordinate(ChannelBufferTools.readHexInteger(buf, 8));
double longitude = convertCoordinate(ChannelBufferTools.readHexInteger(buf, 9));
byte flags = buf.readByte();
position.setValid((flags & 0x1) == 0x1);
if ((flags & 0x2) == 0) {
latitude = -latitude;
}
position.setLatitude(latitude);
if ((flags & 0x4) == 0) {
longitude = -longitude;
}
position.setLongitude(longitude);
position.setSpeed(ChannelBufferTools.readHexInteger(buf, 2));
position.setCourse(buf.readUnsignedByte() * 2.0);
if (version == 1) {
position.set(Event.KEY_SATELLITES, buf.readUnsignedByte());
position.set(Event.KEY_POWER, buf.readUnsignedByte());
buf.readByte(); // other flags and sensors
position.setAltitude(buf.readUnsignedShort());
int cid = buf.readUnsignedShort();
int lac = buf.readUnsignedShort();
if (cid != 0 && lac != 0) {
position.set(Event.KEY_CID, cid);
position.set(Event.KEY_LAC, lac);
}
position.set(Event.KEY_GSM, buf.readUnsignedByte());
} else if (version == 2) {
int fuel = buf.readUnsignedByte() << 8;
position.set(Event.KEY_STATUS, buf.readUnsignedInt());
position.set(Event.KEY_ODOMETER, buf.readUnsignedInt());
fuel += buf.readUnsignedByte();
position.set(Event.KEY_FUEL, fuel);
}
return position;
}