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.buffer.ByteBufUtil; 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; public class AnytrekProtocolDecoder extends BaseProtocolDecoder { public AnytrekProtocolDecoder(Protocol protocol) { super(protocol); } private void sendResponse(Channel channel, SocketAddress remoteAddress, int type) { if (channel != null) { ByteBuf response = Unpooled.buffer(); response.writeShort(0x7878); response.writeShortLE(1 + 1 + 2 + 1 + 2); // length response.writeByte(type); response.writeByte(0); // error response.writeShortLE(0); // report interval response.writeByte(0); // clear alarm response.writeShortLE(0); // checksum response.writeByte('\r'); response.writeByte('\n'); channel.writeAndFlush(new NetworkMessage(response, remoteAddress)); } } @Override protected Object decode(Channel channel, SocketAddress remoteAddress, Object msg) throws Exception { ByteBuf buf = (ByteBuf) msg; buf.skipBytes(2); // header buf.readUnsignedShortLE(); // size int type = buf.readUnsignedByte(); String imei = ByteBufUtil.hexDump(buf.readSlice(8)).substring(2); DeviceSession deviceSession = getDeviceSession(channel, remoteAddress, imei); if (deviceSession == null) { return null; } Position position = new Position(getProtocolName()); position.setDeviceId(deviceSession.getDeviceId()); position.set(Position.KEY_VERSION_FW, buf.readUnsignedShortLE()); position.set(Position.KEY_BATTERY, buf.readUnsignedShortLE() * 0.01); position.set(Position.KEY_RSSI, buf.readUnsignedByte()); DateBuilder dateBuilder = new DateBuilder() .setDate(buf.readUnsignedByte(), buf.readUnsignedByte(), buf.readUnsignedByte()) .setTime(buf.readUnsignedByte(), buf.readUnsignedByte(), buf.readUnsignedByte()); position.setTime(dateBuilder.getDate()); position.set(Position.KEY_SATELLITES, BitUtil.to(buf.readUnsignedByte(), 4)); double latitude = buf.readUnsignedIntLE() / 1800000.0; double longitude = buf.readUnsignedIntLE() / 1800000.0; position.setSpeed(UnitsConverter.knotsFromKph(buf.readUnsignedByte())); int flags = buf.readUnsignedShortLE(); position.setCourse(BitUtil.to(flags, 10)); position.setValid(BitUtil.check(flags, 12)); if (!BitUtil.check(flags, 10)) { latitude = -latitude; } if (BitUtil.check(flags, 11)) { longitude = -longitude; } position.setLatitude(latitude); position.setLongitude(longitude); buf.readUnsignedIntLE(); // info index buf.readUnsignedIntLE(); // setting index flags = buf.readUnsignedByte(); position.set(Position.KEY_CHARGE, BitUtil.check(flags, 0)); position.set(Position.KEY_IGNITION, BitUtil.check(flags, 1)); position.set(Position.KEY_ALARM, BitUtil.check(flags, 4) ? Position.ALARM_GENERAL : null); buf.readUnsignedShortLE(); // charge current position.set(Position.KEY_ODOMETER, buf.readUnsignedIntLE()); sendResponse(channel, remoteAddress, type); return position; } }