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.ByteBufUtil; import io.netty.channel.Channel; import org.traccar.BaseProtocolDecoder; import org.traccar.DeviceSession; import org.traccar.Protocol; import org.traccar.helper.BcdUtil; 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.util.Arrays; import java.util.Date; public class Vt200ProtocolDecoder extends BaseProtocolDecoder { public Vt200ProtocolDecoder(Protocol protocol) { super(protocol); } private static double decodeCoordinate(int value) { int degrees = value / 1000000; int minutes = value % 1000000; return degrees + minutes * 0.0001 / 60; } protected Date decodeDate(ByteBuf buf) { DateBuilder dateBuilder = new DateBuilder() .setDateReverse(BcdUtil.readInteger(buf, 2), BcdUtil.readInteger(buf, 2), BcdUtil.readInteger(buf, 2)) .setTime(BcdUtil.readInteger(buf, 2), BcdUtil.readInteger(buf, 2), BcdUtil.readInteger(buf, 2)); return dateBuilder.getDate(); } @Override protected Object decode(Channel channel, SocketAddress remoteAddress, Object msg) throws Exception { ByteBuf buf = (ByteBuf) msg; buf.skipBytes(1); // header String id = ByteBufUtil.hexDump(buf.readSlice(6)); DeviceSession deviceSession = getDeviceSession(channel, remoteAddress, id); if (deviceSession == null) { return null; } int type = buf.readUnsignedShort(); buf.readUnsignedShort(); // length if (type == 0x2086 || type == 0x2084 || type == 0x2082) { Position position = new Position(getProtocolName()); position.setDeviceId(deviceSession.getDeviceId()); buf.readUnsignedByte(); // data type buf.readUnsignedShort(); // trip id position.setTime(decodeDate(buf)); position.setLatitude(decodeCoordinate(BcdUtil.readInteger(buf, 8))); position.setLongitude(decodeCoordinate(BcdUtil.readInteger(buf, 9))); int flags = buf.readUnsignedByte(); position.setValid(BitUtil.check(flags, 0)); if (!BitUtil.check(flags, 1)) { position.setLatitude(-position.getLatitude()); } if (!BitUtil.check(flags, 2)) { position.setLongitude(-position.getLongitude()); } position.setSpeed(UnitsConverter.knotsFromKph(buf.readUnsignedByte())); position.setCourse(buf.readUnsignedByte() * 2); position.set(Position.KEY_SATELLITES, buf.readUnsignedByte()); position.set(Position.KEY_RSSI, buf.readUnsignedByte()); position.set(Position.KEY_ODOMETER, buf.readUnsignedInt() * 1000); position.set(Position.KEY_STATUS, buf.readUnsignedInt()); // additional data return position; } else if (type == 0x3088) { Position position = new Position(getProtocolName()); position.setDeviceId(deviceSession.getDeviceId()); getLastLocation(position, null); buf.readUnsignedShort(); // trip id buf.skipBytes(8); // imei buf.skipBytes(8); // imsi position.set("tripStart", decodeDate(buf).getTime()); position.set("tripEnd", decodeDate(buf).getTime()); position.set("drivingTime", buf.readUnsignedShort()); position.set(Position.KEY_FUEL_CONSUMPTION, buf.readUnsignedInt()); position.set(Position.KEY_ODOMETER_TRIP, buf.readUnsignedInt()); position.set("maxSpeed", UnitsConverter.knotsFromKph(buf.readUnsignedByte())); position.set("maxRpm", buf.readUnsignedShort()); position.set("maxTemp", buf.readUnsignedByte() - 40); position.set("hardAccelerationCount", buf.readUnsignedByte()); position.set("hardBrakingCount", buf.readUnsignedByte()); for (String speedType : Arrays.asList("over", "high", "normal", "low")) { position.set(speedType + "SpeedTime", buf.readUnsignedShort()); position.set(speedType + "SpeedDistance", buf.readUnsignedInt()); position.set(speedType + "SpeedFuel", buf.readUnsignedInt()); } position.set("idleTime", buf.readUnsignedShort()); position.set("idleFuel", buf.readUnsignedInt()); position.set("hardCorneringCount", buf.readUnsignedByte()); position.set("overspeedCount", buf.readUnsignedByte()); position.set("overheatCount", buf.readUnsignedShort()); position.set("laneChangeCount", buf.readUnsignedByte()); position.set("emergencyRefueling", buf.readUnsignedByte()); return position; } return null; } }