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A Mode S and ADS-B decoding library for Java
There is a newer version: 3.4.0
package org.opensky.example;
/**
 *  This file is part of org.opensky.libadsb.
 *
 *  org.opensky.libadsb is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  (at your option) any later version.
 *
 *  org.opensky.libadsb is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with org.opensky.libadsb.  If not, see .
 */

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Scanner;

import org.opensky.libadsb.Decoder;
import org.opensky.libadsb.Position;
import org.opensky.libadsb.PositionDecoder;
import org.opensky.libadsb.tools;
import org.opensky.libadsb.exceptions.BadFormatException;
import org.opensky.libadsb.exceptions.UnspecifiedFormatError;
import org.opensky.libadsb.msgs.AirbornePositionMsg;
import org.opensky.libadsb.msgs.AirspeedHeadingMsg;
import org.opensky.libadsb.msgs.AllCallReply;
import org.opensky.libadsb.msgs.AltitudeReply;
import org.opensky.libadsb.msgs.CommBAltitudeReply;
import org.opensky.libadsb.msgs.CommBIdentifyReply;
import org.opensky.libadsb.msgs.CommDExtendedLengthMsg;
import org.opensky.libadsb.msgs.EmergencyOrPriorityStatusMsg;
import org.opensky.libadsb.msgs.ExtendedSquitter;
import org.opensky.libadsb.msgs.IdentificationMsg;
import org.opensky.libadsb.msgs.IdentifyReply;
import org.opensky.libadsb.msgs.LongACAS;
import org.opensky.libadsb.msgs.MilitaryExtendedSquitter;
import org.opensky.libadsb.msgs.ModeSReply;
import org.opensky.libadsb.msgs.OperationalStatusMsg;
import org.opensky.libadsb.msgs.ShortACAS;
import org.opensky.libadsb.msgs.SurfacePositionMsg;
import org.opensky.libadsb.msgs.TCASResolutionAdvisoryMsg;
import org.opensky.libadsb.msgs.VelocityOverGroundMsg;

/**
 * ADS-B decoder example: It reads STDIN line-by-line. It should be fed with
 * comma-separated timestamp and message. Example input:
 * 
 * 1,8d4b19f39911088090641010b9b0
 * 2,8d4ca513587153a8184a2fb5adeb
 * 3,8d3413c399014e23c80f947ce87c
 * 4,5d4ca88c079afe
 * 5,a0001838ca3e51f0a8000047a36a
 * 6,8d47a36a58c38668ffb55f000000
 * 7,5d506c28000000
 * 8,a8000102fe81c1000000004401e3
 * 9,a0001839000000000000004401e3
 * 
 * @author Matthias Schäfer ([email protected])
 */
public class ExampleDecoder {
	// we store the position decoder for each aircraft
	HashMap decs;
	private PositionDecoder dec;
	
	public ExampleDecoder() {
		decs = new HashMap();
	}

	public void decodeMsg(double timestamp, String raw, String icao) throws Exception {
		ModeSReply msg;
		try {
			msg = Decoder.genericDecoder(raw);
		} catch (BadFormatException e) {
			System.out.println("Malformed message! Skipping it. Message: "+e.getMessage());
			return;
		} catch (UnspecifiedFormatError e) {
			System.out.println("Unspecified message! Skipping it...");
			return;
		}
		
		String icao24 = tools.toHexString(msg.getIcao24());
		
		if (icao != null && !icao.toLowerCase().equals(icao24)) return;

		// check for erroneous messages; some receivers set
		// parity field to the result of the CRC polynomial division
		if (tools.isZero(msg.getParity()) || msg.checkParity()) { // CRC is ok
			
			// cleanup decoders every 100.000 messages to avoid excessive memory usage
			// therefore, remove decoders which have not been used for more than one hour.
			List to_remove = new ArrayList();
			for (String key : decs.keySet())
				if (decs.get(key).getLastUsedTime() 0) {
			icao = args[0];
			System.err.println("Set filter to ICAO 24-bit ID '"+icao+"'.");
		}
		
		// iterate over STDIN
		Scanner sc = new Scanner(System.in, "UTF-8");
		ExampleDecoder dec = new ExampleDecoder();
		while(sc.hasNext()) {
		  String[] values = sc.nextLine().split(",");
		  dec.decodeMsg(Double.parseDouble(values[0]), values[1], icao);
		}
		sc.close();
	}
}