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 io.netty.handler.codec.http.DefaultFullHttpResponse; import io.netty.handler.codec.http.FullHttpRequest; import io.netty.handler.codec.http.FullHttpResponse; import io.netty.handler.codec.http.HttpResponseStatus; import io.netty.handler.codec.http.HttpVersion; import org.slf4j.Logger; import org.slf4j.LoggerFactory; 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.DateBuilder; 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 Mta6ProtocolDecoder extends BaseProtocolDecoder { private static final Logger LOGGER = LoggerFactory.getLogger(Mta6ProtocolDecoder.class); private final boolean simple; public Mta6ProtocolDecoder(Protocol protocol, boolean simple) { super(protocol); this.simple = simple; } private void sendContinue(Channel channel) { FullHttpResponse response = new DefaultFullHttpResponse(HttpVersion.HTTP_1_1, HttpResponseStatus.CONTINUE); channel.writeAndFlush(new NetworkMessage(response, channel.remoteAddress())); } private void sendResponse(Channel channel, short packetId, short packetCount) { ByteBuf begin = Unpooled.copiedBuffer("#ACK#", StandardCharsets.US_ASCII); ByteBuf end = Unpooled.buffer(3); end.writeByte(packetId); end.writeByte(packetCount); end.writeByte(0); FullHttpResponse response = new DefaultFullHttpResponse(HttpVersion.HTTP_1_1, HttpResponseStatus.OK, Unpooled.wrappedBuffer(begin, end)); channel.writeAndFlush(new NetworkMessage(response, channel.remoteAddress())); } private static class FloatReader { private int previousFloat; public float readFloat(ByteBuf buf) { switch (buf.getUnsignedByte(buf.readerIndex()) >> 6) { case 0: previousFloat = buf.readInt() << 2; break; case 1: previousFloat = (previousFloat & 0xffffff00) + ((buf.readUnsignedByte() & 0x3f) << 2); break; case 2: previousFloat = (previousFloat & 0xffff0000) + ((buf.readUnsignedShort() & 0x3fff) << 2); break; case 3: previousFloat = (previousFloat & 0xff000000) + ((buf.readUnsignedMedium() & 0x3fffff) << 2); break; default: LOGGER.warn("MTA6 float decoding error", new IllegalArgumentException()); break; } return Float.intBitsToFloat(previousFloat); } } private static class TimeReader extends FloatReader { private long weekNumber; public Date readTime(ByteBuf buf) { long weekTime = (long) (readFloat(buf) * 1000); if (weekNumber == 0) { weekNumber = buf.readUnsignedShort(); } DateBuilder dateBuilder = new DateBuilder().setDate(1980, 1, 6); dateBuilder.addMillis(weekNumber * 7 * 24 * 60 * 60 * 1000 + weekTime); return dateBuilder.getDate(); } } private List<Position> parseFormatA(DeviceSession deviceSession, ByteBuf buf) { List<Position> positions = new LinkedList<>(); FloatReader latitudeReader = new FloatReader(); FloatReader longitudeReader = new FloatReader(); TimeReader timeReader = new TimeReader(); try { while (buf.isReadable()) { Position position = new Position(getProtocolName()); position.setDeviceId(deviceSession.getDeviceId()); short flags = buf.readUnsignedByte(); short event = buf.readUnsignedByte(); if (BitUtil.check(event, 7)) { if (BitUtil.check(event, 6)) { buf.skipBytes(8); } else { while (BitUtil.check(event, 7)) { event = buf.readUnsignedByte(); } } } position.setLatitude(latitudeReader.readFloat(buf) / Math.PI * 180); position.setLongitude(longitudeReader.readFloat(buf) / Math.PI * 180); position.setTime(timeReader.readTime(buf)); if (BitUtil.check(flags, 0)) { buf.readUnsignedByte(); // status } if (BitUtil.check(flags, 1)) { position.setAltitude(buf.readUnsignedShort()); } if (BitUtil.check(flags, 2)) { position.setSpeed(buf.readUnsignedShort() & 0x03ff); position.setCourse(buf.readUnsignedByte()); } if (BitUtil.check(flags, 3)) { position.set(Position.KEY_ODOMETER, buf.readUnsignedShort() * 1000); } if (BitUtil.check(flags, 4)) { position.set(Position.KEY_FUEL_CONSUMPTION + "Accumulator1", buf.readUnsignedInt()); position.set(Position.KEY_FUEL_CONSUMPTION + "Accumulator2", buf.readUnsignedInt()); position.set("hours1", buf.readUnsignedShort()); position.set("hours2", buf.readUnsignedShort()); } if (BitUtil.check(flags, 5)) { position.set(Position.PREFIX_ADC + 1, buf.readUnsignedShort() & 0x03ff); position.set(Position.PREFIX_ADC + 2, buf.readUnsignedShort() & 0x03ff); position.set(Position.PREFIX_ADC + 3, buf.readUnsignedShort() & 0x03ff); position.set(Position.PREFIX_ADC + 4, buf.readUnsignedShort() & 0x03ff); } if (BitUtil.check(flags, 6)) { position.set(Position.PREFIX_TEMP + 1, buf.readByte()); buf.getUnsignedByte(buf.readerIndex()); // control (>> 4) position.set(Position.KEY_INPUT, buf.readUnsignedShort() & 0x0fff); buf.readUnsignedShort(); // old sensor state (& 0x0fff) } if (BitUtil.check(flags, 7)) { position.set(Position.KEY_BATTERY, buf.getUnsignedByte(buf.readerIndex()) >> 2); position.set(Position.KEY_POWER, buf.readUnsignedShort() & 0x03ff); position.set(Position.KEY_DEVICE_TEMP, buf.readByte()); position.set(Position.KEY_RSSI, (buf.getUnsignedByte(buf.readerIndex()) >> 4) & 0x07); int satellites = buf.readUnsignedByte() & 0x0f; position.setValid(satellites >= 3); position.set(Position.KEY_SATELLITES, satellites); } positions.add(position); } } catch (IndexOutOfBoundsException error) { LOGGER.warn("MTA6 parsing error", error); } return positions; } private Position parseFormatA1(DeviceSession deviceSession, ByteBuf buf) { Position position = new Position(getProtocolName()); position.setDeviceId(deviceSession.getDeviceId()); short flags = buf.readUnsignedByte(); // Skip events short event = buf.readUnsignedByte(); if (BitUtil.check(event, 7)) { if (BitUtil.check(event, 6)) { buf.skipBytes(8); } else { while (BitUtil.check(event, 7)) { event = buf.readUnsignedByte(); } } } position.setLatitude(new FloatReader().readFloat(buf) / Math.PI * 180); position.setLongitude(new FloatReader().readFloat(buf) / Math.PI * 180); position.setTime(new TimeReader().readTime(buf)); position.set(Position.KEY_STATUS, buf.readUnsignedByte()); if (BitUtil.check(flags, 0)) { position.setAltitude(buf.readUnsignedShort()); position.setSpeed(buf.readUnsignedByte()); position.setCourse(buf.readByte()); position.set(Position.KEY_ODOMETER, new FloatReader().readFloat(buf)); } if (BitUtil.check(flags, 1)) { position.set(Position.KEY_FUEL_CONSUMPTION, new FloatReader().readFloat(buf)); position.set(Position.KEY_HOURS, UnitsConverter.msFromHours(new FloatReader().readFloat(buf))); position.set("tank", buf.readUnsignedByte() * 0.4); } if (BitUtil.check(flags, 2)) { position.set("engine", buf.readUnsignedShort() * 0.125); position.set("pedals", buf.readUnsignedByte()); position.set(Position.PREFIX_TEMP + 1, buf.readUnsignedByte() - 40); position.set(Position.KEY_ODOMETER_SERVICE, buf.readUnsignedShort()); } if (BitUtil.check(flags, 3)) { position.set(Position.KEY_FUEL_LEVEL, buf.readUnsignedShort()); position.set(Position.PREFIX_ADC + 2, buf.readUnsignedShort()); position.set(Position.PREFIX_ADC + 3, buf.readUnsignedShort()); position.set(Position.PREFIX_ADC + 4, buf.readUnsignedShort()); } if (BitUtil.check(flags, 4)) { position.set(Position.PREFIX_TEMP + 1, buf.readByte()); buf.getUnsignedByte(buf.readerIndex()); // control (>> 4) position.set(Position.KEY_INPUT, buf.readUnsignedShort() & 0x0fff); buf.readUnsignedShort(); // old sensor state (& 0x0fff) } if (BitUtil.check(flags, 5)) { position.set(Position.KEY_BATTERY, buf.getUnsignedByte(buf.readerIndex()) >> 2); position.set(Position.KEY_POWER, buf.readUnsignedShort() & 0x03ff); position.set(Position.KEY_DEVICE_TEMP, buf.readByte()); position.set(Position.KEY_RSSI, buf.getUnsignedByte(buf.readerIndex()) >> 5); int satellites = buf.readUnsignedByte() & 0x1f; position.setValid(satellites >= 3); position.set(Position.KEY_SATELLITES, satellites); } // other data return position; } @Override protected Object decode(Channel channel, SocketAddress remoteAddress, Object msg) throws Exception { FullHttpRequest request = (FullHttpRequest) msg; ByteBuf buf = request.content(); buf.skipBytes("id=".length()); int index = buf.indexOf(buf.readerIndex(), buf.writerIndex(), (byte) '&'); String uniqueId = buf.toString(buf.readerIndex(), index - buf.readerIndex(), StandardCharsets.US_ASCII); DeviceSession deviceSession = getDeviceSession(channel, remoteAddress, uniqueId); if (deviceSession == null) { return null; } buf.skipBytes(uniqueId.length()); buf.skipBytes("&bin=".length()); short packetId = buf.readUnsignedByte(); short offset = buf.readUnsignedByte(); // dataOffset short packetCount = buf.readUnsignedByte(); buf.readUnsignedByte(); // reserved buf.readUnsignedByte(); // timezone buf.skipBytes(offset - 5); if (channel != null) { sendContinue(channel); sendResponse(channel, packetId, packetCount); } if (packetId == 0x31 || packetId == 0x32 || packetId == 0x36) { if (simple) { return parseFormatA1(deviceSession, buf); } else { return parseFormatA(deviceSession, buf); } } // else if (0x34 0x38 0x4F 0x59) return null; } }