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 getByName(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() );
        }

        //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.
        // 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
        @Deprecated
        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 id";
                
                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	package dk.thoerup.traininfoservice.db;
2
3	import java.sql.Array;
4	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	import java.util.logging.Logger;
10
11	import dk.thoerup.android.traininfo.common.StationBean;
12	import dk.thoerup.android.traininfo.common.StationEntry;
13
14	public class StationDAO {
15
16	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	public static class NostationException extends Exception {
25	private static final long serialVersionUID = 1L;
26	}
27
28	final static int LOCATION_LIMIT = 8;
29	static final Logger logger = Logger.getLogger(StationDAO.class.getName());
30
31
32	private StationEntry convertSingleRow(ResultSet res) throws SQLException {
33	StationEntry station = new StationEntry();
34
35	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
45	station.setIsRegional( station.getRegional() != null );
46	station.setIsStrain( station.getStrain() != null );
47	station.setIsMetro( station.getMetro() != null );
48
49	return station;
50	}
51
52	private StationBean convertResultset(ResultSet res) throws SQLException {
53	StationBean stations = new StationBean();
54	while (res.next()) {
55	stations.entries.add( convertSingleRow(res) );
56	}
57	return stations;
58
59	}
60
61	private StationBean fetchStations(String SQL, StatementParamSetter setter) throws SQLException {
62	StationBean stations;
63	Connection conn = null;
64	PreparedStatement stmt = null;
65	ResultSet res = null;
66	try {
67	conn = DBConnection.getConnection();
68	stmt = conn.prepareStatement(SQL);
69
70	setter.setParams(stmt);
71
72	res = stmt.executeQuery();
73	stations = convertResultset(res);
74
75	} finally {
76	if (res != null)
77	res.close();
78	if (stmt != null)
79	stmt.close();
80	if (conn!= null)
81	conn.close();
82	}
83	return stations;
84
85	}
86
87	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	}
99
100
101
102	/*
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	* create operator ~~~ (procedure = rlike, leftarg = text, rightarg = text, commutator = ~~);
107	*/
108	public StationBean getByName(final String name) throws SQLException {
109	String SQL = "SELECT id,name,latitude,longitude,stationcode_fjrn,stationcode_stog, stationcode_metro, address, 0.0 " +
110	"FROM trainstations " +
111	"WHERE (name ILIKE ? OR ? ~~~ ANY(aliases)) AND enabled = true " +
112	"ORDER BY name ";
113
114	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	}
121
122	return fetchStations(SQL, new NameSetter() );
123	}
124
125	//Latitude (horizonal), longitude(vertical) so
126	// 1 degree latitude is ~ 111320 meters, since the distance between the horizonal lines is always the same
127	// 1 degree longitude is ~111320 meters at equator but gets shorter as we get closer to the poles.
128	// the "hack" with max 0.4 degrees latitude and 0.75 degrees longitude is only valid since we only service danish trains,
129	// in denmark 0.4dg latitude ~ 44km, 0.75dg longitude ~ 47km
130
131	// the ultra fast method (and only slightly inaccurate as long as we only cover a limited geographically area)
132	// is using an aproximation of the length of 1 latitude degree and 1 longitude degree and just use pythagoras to
133	// calculate the distance:
134	// sqrt( power(abs(latitude-?)111320, 2) + power(abs(longitude-?)63000,2) )::int as calcdist
135
136	public StationBean getByLocationWorker(final double latitude, final double longitude, final boolean geolimit) throws SQLException {
137
138	String limitExpression = (geolimit == true) ? "AND abs(latitude-?)<0.4 AND abs(longitude-?)<0.75 " : "";
139
140	String SQL = "SELECT id,name,latitude,longitude,stationcode_fjrn,stationcode_stog, stationcode_metro, address, " +
141	"earth_distance( earth_coord, ll_to_earth(?,?))::int AS calcdist " +
142	"FROM trainstations " +
143	"WHERE enabled = true " + limitExpression +
144	"ORDER BY calcdist ASC " +
145	"LIMIT " + LOCATION_LIMIT;
146
147
148	class LatlongSetter implements StatementParamSetter {
149	@Override
150	public void setParams(PreparedStatement stmt) throws SQLException {
151	stmt.setDouble(1, latitude);
152	stmt.setDouble(2, longitude);
153	if (geolimit == true) {
154	stmt.setDouble(3, latitude);
155	stmt.setDouble(4, longitude);
156	}
157	}
158	}
159
160	return fetchStations(SQL, new LatlongSetter() );
161	}
162
163	public StationBean getByLocation(double latitude, double longitude) throws SQLException {
164	StationBean result = getByLocationWorker(latitude, longitude, true);
165
166	if (result.entries.size() < LOCATION_LIMIT) { //failover
167	logger.info("getByLocation failover: " +latitude + "," + longitude);
168
169	result = getByLocationWorker(latitude, longitude, false);
170	}
171
172	return result;
173	}
174
175
176
177	public StationBean getByList(String list) throws SQLException {
178	String SQL = "SELECT id,name,latitude,longitude,stationcode_fjrn,stationcode_stog,stationcode_metro, address,0.0 " +
179	"FROM trainstations " +
180	"WHERE id IN " + list + " AND enabled = true " +
181	"ORDER BY name ";
182
183	return fetchStations(SQL, new NullSetter() );
184	}
185
186
187
188	public StationEntry getSimpleByName(final String name) throws SQLException {
189	String SQL = "SELECT id,name,latitude,longitude,stationcode_fjrn,stationcode_stog, stationcode_metro, address, 0.0 " +
190	"FROM trainstations " +
191	"WHERE name = ? AND enabled = true " +
192	"LIMIT 1 ";
193
194	class NameSetter implements StatementParamSetter {
195	@Override
196	public void setParams(PreparedStatement stmt) throws SQLException {
197	stmt.setString(1, name );
198	}
199	}
200
201	StationBean stations = fetchStations(SQL, new NameSetter() );
202
203	if (stations.entries.size() == 1) {
204	return stations.entries.get(0);
205	} else {
206	return null;
207	}
208	}
209
210	//used to create full dump in order to populate Google Appengine DB
211	@Deprecated
212	public StationBean dumpAll() throws SQLException {
213
214	String SQL = "SELECT id,name,latitude,longitude,stationcode_fjrn,stationcode_stog,stationcode_metro,address,0.0,aliases " +
215	"FROM trainstations WHERE enabled = true ORDER BY id";
216
217	Connection conn = null;
218	Statement stmt = null;
219	ResultSet res = null;
220
221
222	try {
223	conn = DBConnection.getConnection();
224
225	stmt = conn.createStatement();
226	res = stmt.executeQuery(SQL);
227
228	// Does mostly the same as convertResultset()
229	StationBean stations = new StationBean();
230	while (res.next()) {
231	StationEntry entry = convertSingleRow(res);
232
233	Array arr = res.getArray(10);
234	if (arr != null) {
235	String[] aliases = (String[]) arr.getArray();
236	entry.setAliases(aliases);
237	}
238
239	stations.entries.add( entry );
240
241	}
242	return stations;
243
244
245	} finally {
246	if (res != null)
247	res.close();
248	if (stmt != null)
249	stmt.close();
250	if (conn != null)
251	conn.close();
252	}
253
254	}
255
256	@Deprecated
257	public static String getStationName(int stationID) {
258	String station = "";
259
260	Connection conn = null;
261	try {
262	conn = DBConnection.getConnection();
263	Statement stmt = conn.createStatement();
264	ResultSet rs = stmt.executeQuery("SELECT name FROM trainstations WHERE id=" + stationID);
265	if (rs.next()) {
266	station = rs.getString(1);
267	}
268
269	} catch (Exception e) {
270	} finally {
271	try {
272	if (conn != null && !conn.isClosed())
273	conn.close();
274	} catch (Exception e) {}
275	}
276
277	return station;
278	}
279
280
281
282	@Deprecated
283	public int getIdByName(final String name) throws SQLException {
284	String SQL = "SELECT id,name,latitude,longitude,stationcode_fjrn,stationcode_stog, stationcode_metro, address, 0.0 " +
285	"FROM trainstations " +
286	"WHERE name = ? AND enabled = true " +
287	"LIMIT 1 ";
288
289	class NameSetter implements StatementParamSetter {
290	@Override
291	public void setParams(PreparedStatement stmt) throws SQLException {
292	stmt.setString(1, name );
293	}
294	}
295
296	StationBean stations = fetchStations(SQL, new NameSetter() );
297
298	if (stations.entries.size() == 1) {
299	return stations.entries.get(0).getId();
300	} else {
301	return -1;
302	}
303	}
304	}