traininfoservice/db/StationDAO.java

package dk.thoerup.traininfoservice.db;

import java.sql.Array;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.logging.Logger;

import dk.thoerup.android.traininfo.common.StationBean;
import dk.thoerup.android.traininfo.common.StationEntry;

public class StationDAO {
        
        private interface StatementParamSetter {
                public void setParams(PreparedStatement stmt) throws SQLException ;
        }
        private class NullSetter implements StatementParamSetter {
                @Override
                public void setParams(PreparedStatement stmt) throws SQLException {}
        }
        
        public static class NostationException extends Exception {
                private static final long serialVersionUID = 1L;
        }
        
        final static int LOCATION_LIMIT = 8;
        static final Logger logger = Logger.getLogger(StationDAO.class.getName());
        
        
        private StationEntry convertSingleRow(ResultSet res) throws SQLException {
                StationEntry station = new StationEntry();

                station.setId( res.getInt(1) );
                station.setName( res.getString(2) );
                station.setLatitude( res.getDouble(3) );
                station.setLongitude( res.getDouble(4) );
                station.setRegional( res.getString(5) );
                station.setStrain( res.getString(6) );
                station.setMetro( res.getString(7) );
                station.setAddress( res.getString(8) );
                station.setCalcdist( (int)res.getDouble(9) );
                
                station.setIsRegional( station.getRegional() != null );
                station.setIsStrain( station.getStrain() != null );
                station.setIsMetro( station.getMetro() != null );

                return station;
        }

        private StationBean convertResultset(ResultSet res) throws SQLException {
                StationBean stations = new StationBean();
                while (res.next()) {
                        stations.entries.add( convertSingleRow(res) );
                }
                return stations;

        }

        private StationBean fetchStations(String SQL, StatementParamSetter setter) throws SQLException {
                StationBean stations;
                Connection conn = null;
                PreparedStatement stmt = null;
                ResultSet res = null;
                try {
                        conn = DBConnection.getConnection();
                        stmt = conn.prepareStatement(SQL);
                        
                        setter.setParams(stmt);

                        res = stmt.executeQuery();
                        stations = convertResultset(res);

                } finally {
                        if (res != null)
                                res.close();
                        if (stmt != null)
                                stmt.close();
                        if (conn!= null)
                                conn.close();
                }
                return stations;
                
        }

        public StationEntry getById(int id) throws SQLException,NostationException {
                String SQL = "SELECT id,name,latitude,longitude,stationcode_fjrn,stationcode_stog,stationcode_metro,address,0.0 " +
                "FROM trainstations WHERE id=" + id + " AND enabled=true";
                                
                StationBean stations =  fetchStations(SQL, new NullSetter() );
                
                if (stations.entries.size() > 0 ) {
                        return stations.entries.get(0);
                } else {
                        throw new NostationException();
                }
        }
        

        /*
         * this code requires theses statements are run on database in order to do ILIKE searches against aliases (which is defines as array of varchar(64) )
         *     create function rlike(text,text) returns bool as 
         *     'select $2 ilike $1' language sql strict immutable;
         *     create operator ~~~ (procedure = rlike, leftarg = text, rightarg = text, commutator = ~~);
         */
        public StationBean getByNameNormal(final String name) throws SQLException {
                String SQL = "SELECT id,name,latitude,longitude,stationcode_fjrn,stationcode_stog, stationcode_metro, address, 0.0 " + 
                "FROM trainstations " + 
                "WHERE (name ILIKE ? OR ? ~~~ ANY(aliases)) AND enabled = true " +
                "ORDER BY name ";

                class NameSetter implements StatementParamSetter {
                        @Override
                        public void setParams(PreparedStatement stmt) throws SQLException {
                                stmt.setString(1, name + "%");
                                stmt.setString(2, name + "%");                          
                        }                       
                }
                
                return fetchStations(SQL, new NameSetter() );
        }
        
        
        public StationBean getByNameFuzzy(final String name) throws SQLException {
                String SQL = "SELECT * FROM (" +
                                         "    SELECT id,name,latitude,longitude,stationcode_fjrn,stationcode_stog, stationcode_metro, address, 0.0, " +
                                         "    levenshtein(lower(name),lower(?) ) as leven " +
                                         "    FROM trainstations " +
                                         "    WHERE  enabled = true ) as lev2 " +
                                         "WHERE (leven <= 3) " +                
                                         "ORDER BY leven " + 
                                         "LIMIT 1";

                class NameSetter implements StatementParamSetter {
                        @Override
                        public void setParams(PreparedStatement stmt) throws SQLException {
                                stmt.setString(1, name );
                        }                       
                }
                
                StationBean stations = fetchStations(SQL, new NameSetter() );
                stations.fuzzystrmatch = true;
                return stations;
        }
        
        private String removeSuffix(String str, String suffix) {
                if (str.endsWith(suffix)) {
                        return str.substring(0, str.length() - suffix.length() );
                } else {
                        return str;
                }
        }
        
        public StationBean getByName(String name) throws SQLException {
                name = removeSuffix(name, " st.");
                name = removeSuffix(name, " st");
                name = removeSuffix(name, " station");
                
                StationBean stations = getByNameNormal(name);
                
                if (stations.entries.size() == 0) {
                        stations = getByNameFuzzy(name);

                        logger.info("getByName failover: " + name + "(" + (stations.entries.size() >0) + ")" );
                }
                return stations;
        }
        
        
        //Latitude (horizonal), longitude(vertical) so
        // 1 degree latitude is ~ 111320 meters, since the distance between the horizonal lines is always the same 
        // 1 degree longitude is ~111320 meters at equator but gets shorter as we get closer to the poles.
        // so 1 degree longitude is 64.5 km at denmarks southern point (gedser=54.55,11.95)
        // and is 59.4km at northern point (skagen = 57.75,10.65)
        // The "hack" with max 0.4 degrees latitude and 0.75 degrees longitude is only valid since we only service danish trains,
        // in denmark 0.4dg latitude ~ 44km, 0.75dg longitude ~ 47km

        // the ultra fast method  (and only slightly inaccurate as long as we only cover a limited geographically area)
        // is using an aproximation of the length of 1 latitude degree and 1 longitude degree and just use pythagoras to 
        // calculate the distance:
        //     sqrt( power(abs(latitude-?)*111320, 2) + power(abs(longitude-?)*63000,2) )::int as calcdist 

        public StationBean getByLocationWorker(final double latitude, final double longitude, final boolean geolimit) throws SQLException {
                
                String limitExpression = (geolimit == true) ? "AND abs(latitude-?)<0.4 AND abs(longitude-?)<0.75 " : "";
                
                String SQL = "SELECT id,name,latitude,longitude,stationcode_fjrn,stationcode_stog, stationcode_metro, address, " + 
                        "earth_distance( earth_coord, ll_to_earth(?,?))::int AS calcdist " + 
                        "FROM trainstations " +
                        "WHERE enabled = true " + limitExpression +
                        "ORDER BY calcdist ASC " + 
                        "LIMIT " + LOCATION_LIMIT;

                
                class LatlongSetter implements StatementParamSetter {
                        @Override
                        public void setParams(PreparedStatement stmt) throws SQLException {
                                stmt.setDouble(1, latitude);
                                stmt.setDouble(2, longitude);
                                if (geolimit == true) {
                                        stmt.setDouble(3, latitude);
                                        stmt.setDouble(4, longitude);
                                }                               
                        }                       
                }
                
                return fetchStations(SQL, new LatlongSetter() );
        }
        
        public StationBean getByLocation(double latitude, double longitude) throws SQLException {
                StationBean result = getByLocationWorker(latitude, longitude, true);
                
                if (result.entries.size() < LOCATION_LIMIT) { //failover
                        logger.info("getByLocation failover: " +latitude + "," + longitude);
                        
                        result = getByLocationWorker(latitude, longitude, false);
                }
                
                return result;
        }
        
        
        public StationBean getByList(String list) throws SQLException {
                String SQL = "SELECT id,name,latitude,longitude,stationcode_fjrn,stationcode_stog,stationcode_metro, address,0.0 " + 
                "FROM trainstations " + 
                "WHERE id IN " + list + " AND enabled = true " +
                "ORDER BY name ";
                
                return fetchStations(SQL, new NullSetter() );
        }
        

        public StationEntry getSimpleByName(final String name) throws SQLException {
                String SQL = "SELECT id,name,latitude,longitude,stationcode_fjrn,stationcode_stog, stationcode_metro, address, 0.0 " + 
                "FROM trainstations " + 
                "WHERE name = ?  AND enabled = true " +
                "LIMIT 1 ";

                class NameSetter implements StatementParamSetter {
                        @Override
                        public void setParams(PreparedStatement stmt) throws SQLException {
                                stmt.setString(1, name );
                        }                       
                }
                
                StationBean stations = fetchStations(SQL, new NameSetter() );
                
                if (stations.entries.size() == 1) {
                        return stations.entries.get(0);
                } else {
                        return null;
                }
        }
        
        //used to create full dump in order to populate Google Appengine DB
        //after 1.1.0 also used to populate client-side station list
        public StationBean dumpAll() throws SQLException {
                
                String SQL = "SELECT id,name,latitude,longitude,stationcode_fjrn,stationcode_stog,stationcode_metro,address,0.0,aliases " +
                                "FROM trainstations WHERE enabled = true ORDER BY name";
                
                Connection conn = null;
                Statement stmt = null;
                ResultSet res = null;           

                
                try {
                        conn = DBConnection.getConnection();

                        stmt = conn.createStatement();
                        res = stmt.executeQuery(SQL);           
                                                
                        // Does mostly the same as convertResultset()
                        StationBean stations = new StationBean();
                        while (res.next()) {
                                StationEntry entry = convertSingleRow(res);
                                
                                Array arr = res.getArray(10);
                                if (arr != null) {
                                        String[] aliases = (String[]) arr.getArray();
                                        entry.setAliases(aliases);
                                }
                                
                                stations.entries.add( entry );
                                
                        }
                        return stations;
                        

                } finally {
                        if (res != null)
                                res.close();
                        if (stmt != null)
                                stmt.close();
                        if (conn != null)
                                conn.close();
                }
                
        }

        @Deprecated
        public static String getStationName(int stationID) {
                String station = "";

                Connection conn = null;
                try {
                        conn = DBConnection.getConnection();
                        Statement stmt = conn.createStatement();
                        ResultSet rs = stmt.executeQuery("SELECT name FROM trainstations WHERE id=" + stationID);
                        if (rs.next()) {
                                station = rs.getString(1);
                        }

                } catch (Exception e) { 
                } finally {
                        try {
                                if (conn != null && !conn.isClosed())
                                        conn.close();
                        } catch (Exception e) {}
                }

                return station;
        }
        
        
        @Deprecated
        public int getIdByName(final String name) throws SQLException {
                String SQL = "SELECT id,name,latitude,longitude,stationcode_fjrn,stationcode_stog, stationcode_metro, address, 0.0 " + 
                "FROM trainstations " + 
                "WHERE name = ?  AND enabled = true " +
                "LIMIT 1 ";

                class NameSetter implements StatementParamSetter {
                        @Override
                        public void setParams(PreparedStatement stmt) throws SQLException {
                                stmt.setString(1, name );
                        }                       
                }
                
                StationBean stations = fetchStations(SQL, new NameSetter() );
                
                if (stations.entries.size() == 1) {
                        return stations.entries.get(0).getId();
                } else {
                        return -1;
                }
        }
}
1	torben	1255	package dk.thoerup.traininfoservice.db;
2	torben	588
3	torben	1082	import java.sql.Array;
4	torben	588	import java.sql.Connection;
5			import java.sql.PreparedStatement;
6			import java.sql.ResultSet;
7			import java.sql.SQLException;
8			import java.sql.Statement;
9	torben	895	import java.util.logging.Logger;
10	torben	588
11	torben	1061	import dk.thoerup.android.traininfo.common.StationBean;
12	torben	1409	import dk.thoerup.android.traininfo.common.StationEntry;
13	torben	1060
14	torben	588	public class StationDAO {
15	torben	1145
16	torben	1504	private interface StatementParamSetter {
17			public void setParams(PreparedStatement stmt) throws SQLException ;
18			}
19			private class NullSetter implements StatementParamSetter {
20			@Override
21			public void setParams(PreparedStatement stmt) throws SQLException {}
22			}
23
24	torben	1145	public static class NostationException extends Exception {
25			private static final long serialVersionUID = 1L;
26			}
27
28	torben	997	final static int LOCATION_LIMIT = 8;
29	torben	895	static final Logger logger = Logger.getLogger(StationDAO.class.getName());
30	torben	841
31	torben	895
32	torben	1060	private StationEntry convertSingleRow(ResultSet res) throws SQLException {
33			StationEntry station = new StationEntry();
34	torben	836
35	torben	588	station.setId( res.getInt(1) );
36			station.setName( res.getString(2) );
37			station.setLatitude( res.getDouble(3) );
38			station.setLongitude( res.getDouble(4) );
39			station.setRegional( res.getString(5) );
40			station.setStrain( res.getString(6) );
41			station.setMetro( res.getString(7) );
42			station.setAddress( res.getString(8) );
43			station.setCalcdist( (int)res.getDouble(9) );
44	torben	1060
45			station.setIsRegional( station.getRegional() != null );
46			station.setIsStrain( station.getStrain() != null );
47			station.setIsMetro( station.getMetro() != null );
48	torben	836
49	torben	588	return station;
50			}
51	torben	836
52	torben	1060	private StationBean convertResultset(ResultSet res) throws SQLException {
53			StationBean stations = new StationBean();
54	torben	588	while (res.next()) {
55	torben	1060	stations.entries.add( convertSingleRow(res) );
56	torben	588	}
57			return stations;
58	torben	836
59	torben	588	}
60	torben	836
61	torben	1504	private StationBean fetchStations(String SQL, StatementParamSetter setter) throws SQLException {
62			StationBean stations;
63	torben	588	Connection conn = null;
64	torben	1504	PreparedStatement stmt = null;
65	torben	589	ResultSet res = null;
66	torben	588	try {
67			conn = DBConnection.getConnection();
68	torben	1504	stmt = conn.prepareStatement(SQL);
69
70			setter.setParams(stmt);
71	torben	836
72	torben	1504	res = stmt.executeQuery();
73			stations = convertResultset(res);
74
75	torben	588	} finally {
76	torben	589	if (res != null)
77			res.close();
78			if (stmt != null)
79			stmt.close();
80	torben	1504	if (conn!= null)
81	torben	588	conn.close();
82			}
83	torben	1504	return stations;
84
85			}
86	torben	836
87	torben	1504	public StationEntry getById(int id) throws SQLException,NostationException {
88			String SQL = "SELECT id,name,latitude,longitude,stationcode_fjrn,stationcode_stog,stationcode_metro,address,0.0 " +
89			"FROM trainstations WHERE id=" + id + " AND enabled=true";
90
91			StationBean stations = fetchStations(SQL, new NullSetter() );
92
93			if (stations.entries.size() > 0 ) {
94			return stations.entries.get(0);
95			} else {
96			throw new NostationException();
97			}
98	torben	588	}
99	torben	1082
100	torben	836
101	torben	1082
102	torben	714	/*
103			* this code requires theses statements are run on database in order to do ILIKE searches against aliases (which is defines as array of varchar(64) )
104			* create function rlike(text,text) returns bool as
105			* 'select $2 ilike $1' language sql strict immutable;
106	torben	836	* create operator ~~~ (procedure = rlike, leftarg = text, rightarg = text, commutator = ~~);
107	torben	714	*/
108	torben	1507	public StationBean getByNameNormal(final String name) throws SQLException {
109	torben	588	String SQL = "SELECT id,name,latitude,longitude,stationcode_fjrn,stationcode_stog, stationcode_metro, address, 0.0 " +
110			"FROM trainstations " +
111	torben	714	"WHERE (name ILIKE ? OR ? ~~~ ANY(aliases)) AND enabled = true " +
112	torben	588	"ORDER BY name ";
113
114	torben	1504	class NameSetter implements StatementParamSetter {
115			@Override
116			public void setParams(PreparedStatement stmt) throws SQLException {
117			stmt.setString(1, name + "%");
118			stmt.setString(2, name + "%");
119			}
120	torben	588	}
121	torben	1504
122			return fetchStations(SQL, new NameSetter() );
123	torben	588	}
124	torben	1507
125
126			public StationBean getByNameFuzzy(final String name) throws SQLException {
127	torben	1512	String SQL = "SELECT * FROM (" +
128			" SELECT id,name,latitude,longitude,stationcode_fjrn,stationcode_stog, stationcode_metro, address, 0.0, " +
129			" levenshtein(lower(name),lower(?) ) as leven " +
130			" FROM trainstations " +
131			" WHERE enabled = true ) as lev2 " +
132			"WHERE (leven <= 3) " +
133			"ORDER BY leven " +
134			"LIMIT 1";
135	torben	836
136	torben	1507	class NameSetter implements StatementParamSetter {
137			@Override
138			public void setParams(PreparedStatement stmt) throws SQLException {
139			stmt.setString(1, name );
140			}
141			}
142
143			StationBean stations = fetchStations(SQL, new NameSetter() );
144			stations.fuzzystrmatch = true;
145			return stations;
146			}
147
148	torben	1516	private String removeSuffix(String str, String suffix) {
149			if (str.endsWith(suffix)) {
150			return str.substring(0, str.length() - suffix.length() );
151			} else {
152			return str;
153			}
154			}
155
156	torben	1513	public StationBean getByName(String name) throws SQLException {
157	torben	1516	name = removeSuffix(name, " st.");
158			name = removeSuffix(name, " st");
159			name = removeSuffix(name, " station");
160
161	torben	1507	StationBean stations = getByNameNormal(name);
162
163			if (stations.entries.size() == 0) {
164			stations = getByNameFuzzy(name);
165	torben	1515
166			logger.info("getByName failover: " + name + "(" + (stations.entries.size() >0) + ")" );
167	torben	1507	}
168			return stations;
169			}
170
171
172
173	torben	1254	//Latitude (horizonal), longitude(vertical) so
174			// 1 degree latitude is ~ 111320 meters, since the distance between the horizonal lines is always the same
175			// 1 degree longitude is ~111320 meters at equator but gets shorter as we get closer to the poles.
176	torben	1511	// so 1 degree longitude is 64.5 km at denmarks southern point (gedser=54.55,11.95)
177			// and is 59.4km at northern point (skagen = 57.75,10.65)
178			// The "hack" with max 0.4 degrees latitude and 0.75 degrees longitude is only valid since we only service danish trains,
179	torben	928	// in denmark 0.4dg latitude ~ 44km, 0.75dg longitude ~ 47km
180	torben	836
181	torben	741	// the ultra fast method (and only slightly inaccurate as long as we only cover a limited geographically area)
182			// is using an aproximation of the length of 1 latitude degree and 1 longitude degree and just use pythagoras to
183			// calculate the distance:
184	torben	836	// sqrt( power(abs(latitude-?)111320, 2) + power(abs(longitude-?)63000,2) )::int as calcdist
185
186	torben	1504	public StationBean getByLocationWorker(final double latitude, final double longitude, final boolean geolimit) throws SQLException {
187	torben	841
188	torben	929	String limitExpression = (geolimit == true) ? "AND abs(latitude-?)<0.4 AND abs(longitude-?)<0.75 " : "";
189	torben	841
190			String SQL = "SELECT id,name,latitude,longitude,stationcode_fjrn,stationcode_stog, stationcode_metro, address, " +
191			"earth_distance( earth_coord, ll_to_earth(?,?))::int AS calcdist " +
192			"FROM trainstations " +
193			"WHERE enabled = true " + limitExpression +
194			"ORDER BY calcdist ASC " +
195			"LIMIT " + LOCATION_LIMIT;
196	torben	849
197	torben	841
198	torben	1504	class LatlongSetter implements StatementParamSetter {
199			@Override
200			public void setParams(PreparedStatement stmt) throws SQLException {
201			stmt.setDouble(1, latitude);
202			stmt.setDouble(2, longitude);
203			if (geolimit == true) {
204			stmt.setDouble(3, latitude);
205			stmt.setDouble(4, longitude);
206			}
207			}
208			}
209	torben	849
210	torben	1504	return fetchStations(SQL, new LatlongSetter() );
211	torben	588	}
212	torben	841
213	torben	1060	public StationBean getByLocation(double latitude, double longitude) throws SQLException {
214			StationBean result = getByLocationWorker(latitude, longitude, true);
215	torben	841
216	torben	1060	if (result.entries.size() < LOCATION_LIMIT) { //failover
217	torben	894	logger.info("getByLocation failover: " +latitude + "," + longitude);
218
219	torben	841	result = getByLocationWorker(latitude, longitude, false);
220			}
221
222			return result;
223			}
224
225
226	torben	836
227	torben	1060	public StationBean getByList(String list) throws SQLException {
228	torben	836	String SQL = "SELECT id,name,latitude,longitude,stationcode_fjrn,stationcode_stog,stationcode_metro, address,0.0 " +
229			"FROM trainstations " +
230			"WHERE id IN " + list + " AND enabled = true " +
231			"ORDER BY name ";
232	torben	1504
233			return fetchStations(SQL, new NullSetter() );
234			}
235
236	torben	836
237	torben	1504
238			public StationEntry getSimpleByName(final String name) throws SQLException {
239			String SQL = "SELECT id,name,latitude,longitude,stationcode_fjrn,stationcode_stog, stationcode_metro, address, 0.0 " +
240			"FROM trainstations " +
241			"WHERE name = ? AND enabled = true " +
242			"LIMIT 1 ";
243	torben	836
244	torben	1504	class NameSetter implements StatementParamSetter {
245			@Override
246			public void setParams(PreparedStatement stmt) throws SQLException {
247			stmt.setString(1, name );
248			}
249	torben	836	}
250	torben	1504
251			StationBean stations = fetchStations(SQL, new NameSetter() );
252
253			if (stations.entries.size() == 1) {
254			return stations.entries.get(0);
255			} else {
256			return null;
257			}
258			}
259	torben	1505
260			//used to create full dump in order to populate Google Appengine DB
261	torben	1569	//after 1.1.0 also used to populate client-side station list
262	torben	1505	public StationBean dumpAll() throws SQLException {
263
264			String SQL = "SELECT id,name,latitude,longitude,stationcode_fjrn,stationcode_stog,stationcode_metro,address,0.0,aliases " +
265	torben	1573	"FROM trainstations WHERE enabled = true ORDER BY name";
266	torben	1505
267			Connection conn = null;
268			Statement stmt = null;
269			ResultSet res = null;
270	torben	836
271	torben	1505
272			try {
273			conn = DBConnection.getConnection();
274
275			stmt = conn.createStatement();
276			res = stmt.executeQuery(SQL);
277
278			// Does mostly the same as convertResultset()
279			StationBean stations = new StationBean();
280			while (res.next()) {
281			StationEntry entry = convertSingleRow(res);
282
283			Array arr = res.getArray(10);
284			if (arr != null) {
285			String[] aliases = (String[]) arr.getArray();
286			entry.setAliases(aliases);
287			}
288
289			stations.entries.add( entry );
290
291			}
292			return stations;
293
294
295			} finally {
296			if (res != null)
297			res.close();
298			if (stmt != null)
299			stmt.close();
300			if (conn != null)
301			conn.close();
302			}
303
304			}
305
306	torben	1417	@Deprecated
307	torben	836	public static String getStationName(int stationID) {
308			String station = "";
309
310			Connection conn = null;
311			try {
312			conn = DBConnection.getConnection();
313			Statement stmt = conn.createStatement();
314			ResultSet rs = stmt.executeQuery("SELECT name FROM trainstations WHERE id=" + stationID);
315			if (rs.next()) {
316			station = rs.getString(1);
317			}
318
319			} catch (Exception e) {
320			} finally {
321	torben	588	try {
322	torben	836	if (conn != null && !conn.isClosed())
323	torben	588	conn.close();
324	torben	836	} catch (Exception e) {}
325			}
326	torben	650
327	torben	836	return station;
328			}
329	torben	1417
330	torben	1504
331
332	torben	1417	@Deprecated
333	torben	1504	public int getIdByName(final String name) throws SQLException {
334	torben	836	String SQL = "SELECT id,name,latitude,longitude,stationcode_fjrn,stationcode_stog, stationcode_metro, address, 0.0 " +
335			"FROM trainstations " +
336			"WHERE name = ? AND enabled = true " +
337			"LIMIT 1 ";
338	torben	650
339	torben	1504	class NameSetter implements StatementParamSetter {
340			@Override
341			public void setParams(PreparedStatement stmt) throws SQLException {
342			stmt.setString(1, name );
343			}
344	torben	836	}
345	torben	1504
346			StationBean stations = fetchStations(SQL, new NameSetter() );
347
348			if (stations.entries.size() == 1) {
349			return stations.entries.get(0).getId();
350	torben	836	} else {
351			return -1;
352			}
353			}
354	torben	588	}