Java tutorial
/* * Copyright 2016 - 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.slf4j.Logger; import org.slf4j.LoggerFactory; 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.LinkedList; import java.util.List; public class AstraProtocolDecoder extends BaseProtocolDecoder { private static final Logger LOGGER = LoggerFactory.getLogger(AstraProtocolDecoder.class); public AstraProtocolDecoder(Protocol protocol) { super(protocol); } public static final int MSG_HEARTBEAT = 0x1A; public static final int MSG_DATA = 0x10; @Override protected Object decode(Channel channel, SocketAddress remoteAddress, Object msg) throws Exception { ByteBuf buf = (ByteBuf) msg; if (channel != null) { channel.writeAndFlush(new NetworkMessage(Unpooled.wrappedBuffer(new byte[] { 0x06 }), remoteAddress)); } buf.readUnsignedByte(); // protocol buf.readUnsignedShort(); // length String imei = String.format("%08d", buf.readUnsignedInt()) + String.format("%07d", buf.readUnsignedMedium()); DeviceSession deviceSession = getDeviceSession(channel, remoteAddress, imei); if (deviceSession == null) { return null; } List<Position> positions = new LinkedList<>(); while (buf.readableBytes() > 2) { Position position = new Position(getProtocolName()); position.setDeviceId(deviceSession.getDeviceId()); buf.readUnsignedByte(); // index position.setValid(true); position.setLatitude(buf.readInt() * 0.000001); position.setLongitude(buf.readInt() * 0.000001); DateBuilder dateBuilder = new DateBuilder().setDate(1980, 1, 6) .addMillis(buf.readUnsignedInt() * 1000L); position.setTime(dateBuilder.getDate()); position.setSpeed(UnitsConverter.knotsFromKph(buf.readUnsignedByte() * 2)); position.setCourse(buf.readUnsignedByte() * 2); int reason = buf.readUnsignedMedium(); position.set(Position.KEY_EVENT, reason); int status = buf.readUnsignedShort(); position.set(Position.KEY_STATUS, status); position.set(Position.PREFIX_IO + 1, buf.readUnsignedByte()); position.set(Position.PREFIX_ADC + 1, buf.readUnsignedByte()); position.set(Position.KEY_BATTERY, buf.readUnsignedByte()); position.set(Position.KEY_POWER, buf.readUnsignedByte()); buf.readUnsignedByte(); // max journey speed buf.skipBytes(6); // accelerometer position.set(Position.KEY_ODOMETER_TRIP, buf.readUnsignedShort()); buf.readUnsignedShort(); // journey idle time position.setAltitude(buf.readUnsignedByte() * 20); int quality = buf.readUnsignedByte(); position.set(Position.KEY_SATELLITES, quality & 0xf); position.set(Position.KEY_RSSI, quality >> 4); buf.readUnsignedByte(); // geofence events if (BitUtil.check(status, 8)) { position.set(Position.KEY_DRIVER_UNIQUE_ID, buf.readSlice(7).toString(StandardCharsets.US_ASCII)); position.set(Position.KEY_ODOMETER, buf.readUnsignedMedium() * 1000); position.set(Position.KEY_HOURS, UnitsConverter.msFromHours(buf.readUnsignedShort())); } if (BitUtil.check(status, 6)) { LOGGER.warn("Extension data is not supported"); return position; } positions.add(position); } return positions; } }