Java tutorial
/* * Copyright 2018 Anton Tananaev (anton@traccar.org) * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package org.traccar.protocol; import io.netty.buffer.ByteBuf; import io.netty.buffer.Unpooled; import io.netty.channel.Channel; import org.traccar.BaseProtocolDecoder; import org.traccar.DeviceSession; import org.traccar.NetworkMessage; import org.traccar.Protocol; import org.traccar.helper.BitUtil; import org.traccar.helper.UnitsConverter; import org.traccar.model.CellTower; import org.traccar.model.Network; import org.traccar.model.Position; import java.net.SocketAddress; import java.nio.charset.StandardCharsets; import java.util.Date; public class RoboTrackProtocolDecoder extends BaseProtocolDecoder { public RoboTrackProtocolDecoder(Protocol protocol) { super(protocol); } public static final int MSG_ID = 0x00; public static final int MSG_ACK = 0x80; public static final int MSG_GPS = 0x03; public static final int MSG_GSM = 0x04; public static final int MSG_IMAGE_START = 0x06; public static final int MSG_IMAGE_DATA = 0x07; public static final int MSG_IMAGE_END = 0x08; @Override protected Object decode(Channel channel, SocketAddress remoteAddress, Object msg) throws Exception { ByteBuf buf = (ByteBuf) msg; int type = buf.readUnsignedByte(); if (type == MSG_ID) { buf.skipBytes(16); // name String imei = buf.readSlice(15).toString(StandardCharsets.US_ASCII); if (getDeviceSession(channel, remoteAddress, imei) != null && channel != null) { ByteBuf response = Unpooled.buffer(); response.writeByte(MSG_ACK); response.writeByte(0x01); // success response.writeByte(0x66); // checksum channel.writeAndFlush(new NetworkMessage(response, remoteAddress)); } } else if (type == MSG_GPS || type == MSG_GSM) { DeviceSession deviceSession = getDeviceSession(channel, remoteAddress); if (deviceSession == null) { return null; } Position position = new Position(getProtocolName()); position.setDeviceId(deviceSession.getDeviceId()); position.setDeviceTime(new Date(buf.readUnsignedIntLE() * 1000)); if (type == MSG_GPS) { position.setValid(true); position.setFixTime(position.getDeviceTime()); position.setLatitude(buf.readIntLE() * 0.000001); position.setLongitude(buf.readIntLE() * 0.000001); position.setSpeed(UnitsConverter.knotsFromKph(buf.readByte())); } else { getLastLocation(position, position.getDeviceTime()); position.setNetwork(new Network(CellTower.from(buf.readUnsignedShortLE(), buf.readUnsignedShortLE(), buf.readUnsignedShortLE(), buf.readUnsignedShortLE()))); buf.readUnsignedByte(); // reserved } int value = buf.readUnsignedByte(); position.set(Position.KEY_SATELLITES, BitUtil.to(value, 4)); position.set(Position.KEY_RSSI, BitUtil.between(value, 4, 7)); position.set(Position.KEY_MOTION, BitUtil.check(value, 7)); value = buf.readUnsignedByte(); position.set(Position.KEY_CHARGE, BitUtil.check(value, 0)); for (int i = 1; i <= 4; i++) { position.set(Position.PREFIX_IN + i, BitUtil.check(value, i)); } position.set(Position.KEY_BATTERY_LEVEL, BitUtil.from(value, 5) * 100 / 7); position.set(Position.KEY_DEVICE_TEMP, buf.readByte()); for (int i = 1; i <= 3; i++) { position.set(Position.PREFIX_ADC + i, buf.readUnsignedShortLE()); } return position; } return null; } }