/* * Copyright 2016 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 org.jboss.netty.channel.Channel; import org.traccar.BaseProtocolDecoder; import org.traccar.DeviceSession; import org.traccar.helper.BitBuffer; import org.traccar.helper.Parser; import org.traccar.helper.PatternBuilder; import org.traccar.model.Position; import java.net.SocketAddress; import java.util.ArrayList; import java.util.Date; import java.util.HashMap; import java.util.List; import java.util.Map; import java.util.regex.Pattern; public class AisProtocolDecoder extends BaseProtocolDecoder { public AisProtocolDecoder(AisProtocol protocol) { super(protocol); } private static final Pattern PATTERN = new PatternBuilder() .text("!AIVDM,") .number("(d+),") // count .number("(d+),") // index .number("(d+)?,") // id .expression(".,") // radio channel .expression("([^,]+),") // payload .any() .compile(); private Position decodePayload(Channel channel, SocketAddress remoteAddress, BitBuffer buf) { int type = buf.readUnsigned(6); if (type == 1 || type == 2 || type == 3 || type == 18) { buf.readUnsigned(2); int mmsi = buf.readUnsigned(30); DeviceSession deviceSession = getDeviceSession(channel, remoteAddress, String.valueOf(mmsi)); if (deviceSession == null) { return null; } Position position = new Position(); position.setProtocol(getProtocolName()); position.setDeviceId(deviceSession.getDeviceId()); position.setTime(new Date()); if (type == 18) { buf.readUnsigned(8); // reserved } else { position.set(Position.KEY_STATUS, buf.readUnsigned(4)); position.set("turn", buf.readSigned(8)); } position.setSpeed(buf.readUnsigned(10) * 0.1); position.setValid(buf.readUnsigned(1) != 0); position.setLongitude(buf.readSigned(28) * 0.0001 / 60.0); position.setLatitude(buf.readSigned(27) * 0.0001 / 60.0); position.setCourse(buf.readUnsigned(12) * 0.1); position.set("heading", buf.readUnsigned(9)); return position; } return null; } @Override protected Object decode( Channel channel, SocketAddress remoteAddress, Object msg) throws Exception { String[] sentences = ((String) msg).split("\\r\\n"); List<Position> positions = new ArrayList<>(); Map<Integer, BitBuffer> buffers = new HashMap<>(); for (String sentence : sentences) { if (!sentence.isEmpty()) { Parser parser = new Parser(PATTERN, sentence); if (parser.matches()) { int count = parser.nextInt(); int index = parser.nextInt(); int id = parser.nextInt(); Position position = null; if (count == 1) { BitBuffer bits = new BitBuffer(); bits.writeEncoded(parser.next().getBytes()); position = decodePayload(channel, remoteAddress, bits); } else { BitBuffer bits = buffers.get(id); if (bits == null) { bits = new BitBuffer(); buffers.put(id, bits); } bits.writeEncoded(parser.next().getBytes()); if (count == index) { position = decodePayload(channel, remoteAddress, bits); buffers.remove(id); } } if (position != null) { positions.add(position); } } } } return positions; } }