Java tutorial
/* * Copyright 2013 - 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.Checksum; import org.traccar.helper.UnitsConverter; import org.traccar.model.Position; import java.net.SocketAddress; import java.nio.charset.StandardCharsets; import java.util.Date; import java.util.LinkedList; import java.util.List; public class ApelProtocolDecoder extends BaseProtocolDecoder { private long lastIndex; private long newIndex; public ApelProtocolDecoder(Protocol protocol) { super(protocol); } public static final short MSG_NULL = 0; public static final short MSG_REQUEST_TRACKER_ID = 10; public static final short MSG_TRACKER_ID = 11; public static final short MSG_TRACKER_ID_EXT = 12; public static final short MSG_DISCONNECT = 20; public static final short MSG_REQUEST_PASSWORD = 30; public static final short MSG_PASSWORD = 31; public static final short MSG_REQUEST_STATE_FULL_INFO = 90; public static final short MSG_STATE_FULL_INFO_T104 = 92; public static final short MSG_REQUEST_CURRENT_GPS_DATA = 100; public static final short MSG_CURRENT_GPS_DATA = 101; public static final short MSG_REQUEST_SENSORS_STATE = 110; public static final short MSG_SENSORS_STATE = 111; public static final short MSG_SENSORS_STATE_T100 = 112; public static final short MSG_SENSORS_STATE_T100_4 = 113; public static final short MSG_REQUEST_LAST_LOG_INDEX = 120; public static final short MSG_LAST_LOG_INDEX = 121; public static final short MSG_REQUEST_LOG_RECORDS = 130; public static final short MSG_LOG_RECORDS = 131; public static final short MSG_EVENT = 141; public static final short MSG_TEXT = 150; public static final short MSG_ACK_ALARM = 160; public static final short MSG_SET_TRACKER_MODE = 170; public static final short MSG_GPRS_COMMAND = 180; private void sendSimpleMessage(Channel channel, short type) { ByteBuf request = Unpooled.buffer(8); request.writeShortLE(type); request.writeShortLE(0); request.writeIntLE(Checksum.crc32(request.nioBuffer(0, 4))); channel.writeAndFlush(new NetworkMessage(request, channel.remoteAddress())); } private void requestArchive(Channel channel) { if (lastIndex == 0) { lastIndex = newIndex; } else if (newIndex > lastIndex) { ByteBuf request = Unpooled.buffer(14); request.writeShortLE(MSG_REQUEST_LOG_RECORDS); request.writeShortLE(6); request.writeIntLE((int) lastIndex); request.writeShortLE(512); request.writeIntLE(Checksum.crc32(request.nioBuffer(0, 10))); channel.writeAndFlush(new NetworkMessage(request, channel.remoteAddress())); } } @Override protected Object decode(Channel channel, SocketAddress remoteAddress, Object msg) throws Exception { ByteBuf buf = (ByteBuf) msg; int type = buf.readUnsignedShortLE(); boolean alarm = (type & 0x8000) != 0; type = type & 0x7FFF; buf.readUnsignedShortLE(); // length if (alarm) { sendSimpleMessage(channel, MSG_ACK_ALARM); } if (type == MSG_TRACKER_ID) { return null; // unsupported authentication type } if (type == MSG_TRACKER_ID_EXT) { buf.readUnsignedIntLE(); // id int length = buf.readUnsignedShortLE(); buf.skipBytes(length); length = buf.readUnsignedShortLE(); getDeviceSession(channel, remoteAddress, buf.readSlice(length).toString(StandardCharsets.US_ASCII)); } else if (type == MSG_LAST_LOG_INDEX) { long index = buf.readUnsignedIntLE(); if (index > 0) { newIndex = index; requestArchive(channel); } } else if (type == MSG_CURRENT_GPS_DATA || type == MSG_STATE_FULL_INFO_T104 || type == MSG_LOG_RECORDS) { DeviceSession deviceSession = getDeviceSession(channel, remoteAddress); if (deviceSession == null) { return null; } List<Position> positions = new LinkedList<>(); int recordCount = 1; if (type == MSG_LOG_RECORDS) { recordCount = buf.readUnsignedShortLE(); } for (int j = 0; j < recordCount; j++) { Position position = new Position(getProtocolName()); position.setDeviceId(deviceSession.getDeviceId()); int subtype = type; if (type == MSG_LOG_RECORDS) { position.set(Position.KEY_ARCHIVE, true); lastIndex = buf.readUnsignedIntLE() + 1; position.set(Position.KEY_INDEX, lastIndex); subtype = buf.readUnsignedShortLE(); if (subtype != MSG_CURRENT_GPS_DATA && subtype != MSG_STATE_FULL_INFO_T104) { buf.skipBytes(buf.readUnsignedShortLE()); continue; } buf.readUnsignedShortLE(); // length } position.setTime(new Date(buf.readUnsignedIntLE() * 1000)); position.setLatitude(buf.readIntLE() * 180.0 / 0x7FFFFFFF); position.setLongitude(buf.readIntLE() * 180.0 / 0x7FFFFFFF); if (subtype == MSG_STATE_FULL_INFO_T104) { int speed = buf.readUnsignedByte(); position.setValid(speed != 255); position.setSpeed(UnitsConverter.knotsFromKph(speed)); position.set(Position.KEY_HDOP, buf.readByte()); } else { int speed = buf.readShortLE(); position.setValid(speed != -1); position.setSpeed(UnitsConverter.knotsFromKph(speed * 0.01)); } position.setCourse(buf.readShortLE() * 0.01); position.setAltitude(buf.readShortLE()); if (subtype == MSG_STATE_FULL_INFO_T104) { position.set(Position.KEY_SATELLITES, buf.readUnsignedByte()); position.set(Position.KEY_RSSI, buf.readUnsignedByte()); position.set(Position.KEY_EVENT, buf.readUnsignedShortLE()); position.set(Position.KEY_ODOMETER, buf.readUnsignedIntLE()); position.set(Position.KEY_INPUT, buf.readUnsignedByte()); position.set(Position.KEY_OUTPUT, buf.readUnsignedByte()); for (int i = 1; i <= 8; i++) { position.set(Position.PREFIX_ADC + i, buf.readUnsignedShortLE()); } position.set(Position.PREFIX_COUNT + 1, buf.readUnsignedIntLE()); position.set(Position.PREFIX_COUNT + 2, buf.readUnsignedIntLE()); position.set(Position.PREFIX_COUNT + 3, buf.readUnsignedIntLE()); } positions.add(position); } buf.readUnsignedIntLE(); // crc if (type == MSG_LOG_RECORDS) { requestArchive(channel); } else { sendSimpleMessage(channel, MSG_REQUEST_LAST_LOG_INDEX); } return positions; } return null; } }