Java tutorial
/* * Copyright 2012 - 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.slf4j.Logger; import org.slf4j.LoggerFactory; import org.traccar.BaseProtocolDecoder; import org.traccar.Context; import org.traccar.DeviceSession; import org.traccar.Protocol; import org.traccar.helper.BitUtil; import org.traccar.helper.DateBuilder; import org.traccar.model.Position; import java.net.SocketAddress; import java.nio.charset.StandardCharsets; public class SkypatrolProtocolDecoder extends BaseProtocolDecoder { private static final Logger LOGGER = LoggerFactory.getLogger(SkypatrolProtocolDecoder.class); private final long defaultMask; public SkypatrolProtocolDecoder(Protocol protocol) { super(protocol); defaultMask = Context.getConfig().getInteger(getProtocolName() + ".mask"); } private static double convertCoordinate(long coordinate) { int sign = 1; if (coordinate > 0x7fffffffL) { sign = -1; coordinate = 0xffffffffL - coordinate; } long degrees = coordinate / 1000000; double minutes = (coordinate % 1000000) / 10000.0; return sign * (degrees + minutes / 60); } @Override protected Object decode(Channel channel, SocketAddress remoteAddress, Object msg) throws Exception { ByteBuf buf = (ByteBuf) msg; int apiNumber = buf.readUnsignedShort(); int commandType = buf.readUnsignedByte(); int messageType = BitUtil.from(buf.readUnsignedByte(), 4); long mask = defaultMask; if (buf.readUnsignedByte() == 4) { mask = buf.readUnsignedInt(); } // Binary position report if (apiNumber == 5 && commandType == 2 && messageType == 1 && BitUtil.check(mask, 0)) { Position position = new Position(getProtocolName()); if (BitUtil.check(mask, 1)) { position.set(Position.KEY_STATUS, buf.readUnsignedInt()); } String id; if (BitUtil.check(mask, 23)) { id = buf.toString(buf.readerIndex(), 8, StandardCharsets.US_ASCII).trim(); buf.skipBytes(8); } else if (BitUtil.check(mask, 2)) { id = buf.toString(buf.readerIndex(), 22, StandardCharsets.US_ASCII).trim(); buf.skipBytes(22); } else { LOGGER.warn("No device id field"); return null; } DeviceSession deviceSession = getDeviceSession(channel, remoteAddress, id); if (deviceSession == null) { return null; } position.setDeviceId(deviceSession.getDeviceId()); if (BitUtil.check(mask, 3)) { position.set(Position.PREFIX_IO + 1, buf.readUnsignedShort()); } if (BitUtil.check(mask, 4)) { position.set(Position.PREFIX_ADC + 1, buf.readUnsignedShort()); } if (BitUtil.check(mask, 5)) { position.set(Position.PREFIX_ADC + 2, buf.readUnsignedShort()); } if (BitUtil.check(mask, 7)) { buf.readUnsignedByte(); // function category } DateBuilder dateBuilder = new DateBuilder(); if (BitUtil.check(mask, 8)) { dateBuilder.setDateReverse(buf.readUnsignedByte(), buf.readUnsignedByte(), buf.readUnsignedByte()); } if (BitUtil.check(mask, 9)) { position.setValid(buf.readUnsignedByte() == 1); // gps status } if (BitUtil.check(mask, 10)) { position.setLatitude(convertCoordinate(buf.readUnsignedInt())); } if (BitUtil.check(mask, 11)) { position.setLongitude(convertCoordinate(buf.readUnsignedInt())); } if (BitUtil.check(mask, 12)) { position.setSpeed(buf.readUnsignedShort() / 10.0); } if (BitUtil.check(mask, 13)) { position.setCourse(buf.readUnsignedShort() / 10.0); } if (BitUtil.check(mask, 14)) { dateBuilder.setTime(buf.readUnsignedByte(), buf.readUnsignedByte(), buf.readUnsignedByte()); } position.setTime(dateBuilder.getDate()); if (BitUtil.check(mask, 15)) { position.setAltitude(buf.readMedium()); } if (BitUtil.check(mask, 16)) { position.set(Position.KEY_SATELLITES, buf.readUnsignedByte()); } if (BitUtil.check(mask, 17)) { position.set(Position.KEY_BATTERY, buf.readUnsignedShort()); } if (BitUtil.check(mask, 20)) { position.set(Position.KEY_ODOMETER_TRIP, buf.readUnsignedInt()); } if (BitUtil.check(mask, 21)) { position.set(Position.KEY_ODOMETER, buf.readUnsignedInt()); } if (BitUtil.check(mask, 22)) { buf.skipBytes(6); // time of message generation } if (BitUtil.check(mask, 24)) { position.set(Position.KEY_POWER, buf.readUnsignedShort() * 0.001); } if (BitUtil.check(mask, 25)) { buf.skipBytes(18); // gps overspeed } if (BitUtil.check(mask, 26)) { buf.skipBytes(54); // cell information } if (BitUtil.check(mask, 28)) { position.set(Position.KEY_INDEX, buf.readUnsignedShort()); } return position; } return null; } }