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.channel.Channel; import org.traccar.BaseProtocolDecoder; import org.traccar.DeviceSession; import org.traccar.Protocol; import org.traccar.helper.BitUtil; import org.traccar.helper.UnitsConverter; import org.traccar.model.Position; import java.net.SocketAddress; import java.util.Date; public class ContinentalProtocolDecoder extends BaseProtocolDecoder { public ContinentalProtocolDecoder(Protocol protocol) { super(protocol); } public static final int MSG_KEEPALIVE = 0x00; public static final int MSG_STATUS = 0x02; public static final int MSG_ACK = 0x06; public static final int MSG_NACK = 0x15; private double readCoordinate(ByteBuf buf, boolean extended) { long value = buf.readUnsignedInt(); if (extended ? (value & 0x08000000) != 0 : (value & 0x00800000) != 0) { value |= extended ? 0xF0000000 : 0xFF000000; } return (int) value / (extended ? 360000.0 : 3600.0); } @Override protected Object decode(Channel channel, SocketAddress remoteAddress, Object msg) throws Exception { ByteBuf buf = (ByteBuf) msg; buf.skipBytes(2); // header buf.readUnsignedShort(); // length buf.readUnsignedByte(); // software version long serialNumber = buf.readUnsignedInt(); DeviceSession deviceSession = getDeviceSession(channel, remoteAddress, String.valueOf(serialNumber)); if (deviceSession == null) { return null; } buf.readUnsignedByte(); // product int type = buf.readUnsignedByte(); if (type == MSG_STATUS) { Position position = new Position(getProtocolName()); position.setDeviceId(deviceSession.getDeviceId()); position.setFixTime(new Date(buf.readUnsignedInt() * 1000L)); boolean extended = buf.getUnsignedByte(buf.readerIndex()) != 0; position.setLatitude(readCoordinate(buf, extended)); position.setLongitude(readCoordinate(buf, extended)); position.setCourse(buf.readUnsignedShort()); position.setSpeed(UnitsConverter.knotsFromKph(buf.readUnsignedShort())); position.setValid(buf.readUnsignedByte() > 0); position.setDeviceTime(new Date(buf.readUnsignedInt() * 1000L)); position.set(Position.KEY_EVENT, buf.readUnsignedShort()); int input = buf.readUnsignedShort(); position.set(Position.KEY_IGNITION, BitUtil.check(input, 0)); position.set(Position.KEY_INPUT, input); position.set(Position.KEY_OUTPUT, buf.readUnsignedShort()); position.set(Position.KEY_BATTERY, buf.readUnsignedByte()); position.set(Position.KEY_DEVICE_TEMP, buf.readByte()); buf.readUnsignedShort(); // reserved if (buf.readableBytes() > 4) { position.set(Position.KEY_ODOMETER, buf.readUnsignedInt()); } if (buf.readableBytes() > 4) { position.set(Position.KEY_HOURS, UnitsConverter.msFromHours(buf.readUnsignedInt())); } return position; } return null; } }