Java tutorial
/* * Copyright 2017 - 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.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 DmtProtocolDecoder extends BaseProtocolDecoder { public DmtProtocolDecoder(Protocol protocol) { super(protocol); } public static final int MSG_HELLO = 0x00; public static final int MSG_HELLO_RESPONSE = 0x01; public static final int MSG_DATA_RECORD = 0x04; public static final int MSG_COMMIT = 0x05; public static final int MSG_COMMIT_RESPONSE = 0x06; public static final int MSG_DATA_RECORD_64 = 0x10; public static final int MSG_CANNED_REQUEST_1 = 0x14; public static final int MSG_CANNED_RESPONSE_1 = 0x15; public static final int MSG_CANNED_REQUEST_2 = 0x22; public static final int MSG_CANNED_RESPONSE_2 = 0x23; private void sendResponse(Channel channel, int type, ByteBuf content) { if (channel != null) { ByteBuf response = Unpooled.buffer(); response.writeByte(0x02); response.writeByte(0x55); // header response.writeByte(type); response.writeShortLE(content != null ? content.readableBytes() : 0); if (content != null) { response.writeBytes(content); content.release(); } channel.writeAndFlush(new NetworkMessage(response, channel.remoteAddress())); } } private List<Position> decodeFixed64(Channel channel, SocketAddress remoteAddress, ByteBuf buf) { DeviceSession deviceSession = getDeviceSession(channel, remoteAddress); if (deviceSession == null) { return null; } List<Position> positions = new LinkedList<>(); while (buf.readableBytes() >= 64) { Position position = new Position(getProtocolName()); position.setDeviceId(deviceSession.getDeviceId()); buf.readByte(); // type position.set(Position.KEY_INDEX, buf.readUnsignedIntLE()); long time = buf.readUnsignedIntLE(); position.setTime( new DateBuilder().setYear((int) (2000 + (time & 0x3F))).setMonth((int) (time >> 6) & 0xF) .setDay((int) (time >> 10) & 0x1F).setHour((int) (time >> 15) & 0x1F) .setMinute((int) (time >> 20) & 0x3F).setSecond((int) (time >> 26) & 0x3F).getDate()); position.setLongitude(buf.readIntLE() * 0.0000001); position.setLatitude(buf.readIntLE() * 0.0000001); position.setSpeed(UnitsConverter.knotsFromCps(buf.readUnsignedShortLE())); position.setCourse(buf.readUnsignedByte() * 2); position.setAltitude(buf.readShortLE()); buf.readUnsignedShortLE(); // position accuracy buf.readUnsignedByte(); // speed accuracy position.set(Position.KEY_EVENT, buf.readUnsignedByte()); position.setValid(BitUtil.check(buf.readByte(), 0)); position.set(Position.KEY_INPUT, buf.readUnsignedIntLE()); position.set(Position.KEY_OUTPUT, buf.readUnsignedShortLE()); for (int i = 1; i <= 5; i++) { position.set(Position.PREFIX_ADC + i, buf.readShortLE()); } position.set(Position.KEY_DEVICE_TEMP, buf.readByte()); buf.readShortLE(); // accelerometer x buf.readShortLE(); // accelerometer y buf.readShortLE(); // accelerometer z buf.skipBytes(8); // device id position.set(Position.KEY_PDOP, buf.readUnsignedShortLE() * 0.01); buf.skipBytes(2); // reserved buf.readUnsignedShortLE(); // checksum positions.add(position); } return positions; } private List<Position> decodeStandard(Channel channel, SocketAddress remoteAddress, ByteBuf buf) { DeviceSession deviceSession = getDeviceSession(channel, remoteAddress); if (deviceSession == null) { return null; } List<Position> positions = new LinkedList<>(); while (buf.isReadable()) { int recordEnd = buf.readerIndex() + buf.readUnsignedShortLE(); Position position = new Position(getProtocolName()); position.setDeviceId(deviceSession.getDeviceId()); position.set(Position.KEY_INDEX, buf.readUnsignedIntLE()); position.setDeviceTime(new Date(1356998400000L + buf.readUnsignedIntLE() * 1000)); // since 1 Jan 2013 position.set(Position.KEY_EVENT, buf.readUnsignedByte()); while (buf.readerIndex() < recordEnd) { int fieldId = buf.readUnsignedByte(); int fieldLength = buf.readUnsignedByte(); int fieldEnd = buf.readerIndex() + (fieldLength == 255 ? buf.readUnsignedShortLE() : fieldLength); if (fieldId == 0) { position.setFixTime(new Date(1356998400000L + buf.readUnsignedIntLE() * 1000)); position.setLatitude(buf.readIntLE() * 0.0000001); position.setLongitude(buf.readIntLE() * 0.0000001); position.setAltitude(buf.readShortLE()); position.setSpeed(UnitsConverter.knotsFromCps(buf.readUnsignedShortLE())); buf.readUnsignedByte(); // speed accuracy position.setCourse(buf.readUnsignedByte() * 2); position.set(Position.KEY_PDOP, buf.readUnsignedByte() * 0.1); position.setAccuracy(buf.readUnsignedByte()); position.setValid(buf.readUnsignedByte() != 0); } else if (fieldId == 2) { int input = buf.readIntLE(); int output = buf.readUnsignedShortLE(); int status = buf.readUnsignedShortLE(); position.set(Position.KEY_IGNITION, BitUtil.check(input, 0)); position.set(Position.KEY_INPUT, input); position.set(Position.KEY_OUTPUT, output); position.set(Position.KEY_STATUS, status); } else if (fieldId == 6) { while (buf.readerIndex() < fieldEnd) { switch (buf.readUnsignedByte()) { case 1: position.set(Position.KEY_BATTERY, buf.readUnsignedShortLE() * 0.001); break; case 2: position.set(Position.KEY_POWER, buf.readUnsignedShortLE() * 0.01); break; case 3: position.set(Position.KEY_DEVICE_TEMP, buf.readShortLE() * 0.01); break; case 4: position.set(Position.KEY_RSSI, buf.readUnsignedShortLE()); break; case 5: position.set("solarPower", buf.readUnsignedShortLE() * 0.001); break; default: break; } } } buf.readerIndex(fieldEnd); } if (position.getFixTime() == null) { getLastLocation(position, position.getDeviceTime()); } positions.add(position); } return positions; } @Override protected Object decode(Channel channel, SocketAddress remoteAddress, Object msg) throws Exception { ByteBuf buf = (ByteBuf) msg; buf.skipBytes(2); // header int type = buf.readUnsignedByte(); int length = buf.readUnsignedShortLE(); if (type == MSG_HELLO) { buf.readUnsignedIntLE(); // device serial number DeviceSession deviceSession = getDeviceSession(channel, remoteAddress, buf.readSlice(15).toString(StandardCharsets.US_ASCII)); ByteBuf response = Unpooled.buffer(); if (length == 51) { response.writeByte(0); // reserved response.writeIntLE(0); // reserved } else { response.writeIntLE((int) ((System.currentTimeMillis() - 1356998400000L) / 1000)); response.writeIntLE(deviceSession != null ? 0 : 1); // flags } sendResponse(channel, MSG_HELLO_RESPONSE, response); } else if (type == MSG_COMMIT) { ByteBuf response = Unpooled.buffer(0); response.writeByte(1); // flags (success) sendResponse(channel, MSG_COMMIT_RESPONSE, response); } else if (type == MSG_CANNED_REQUEST_1) { ByteBuf response = Unpooled.buffer(0); response.writeBytes(new byte[12]); sendResponse(channel, MSG_CANNED_RESPONSE_1, response); } else if (type == MSG_CANNED_REQUEST_2) { sendResponse(channel, MSG_CANNED_RESPONSE_2, null); } else if (type == MSG_DATA_RECORD_64) { return decodeFixed64(channel, remoteAddress, buf); } else if (type == MSG_DATA_RECORD) { return decodeStandard(channel, remoteAddress, buf); } return null; } }