thoerup/traininfoservice/StationDAO.java

package dk.thoerup.traininfoservice;

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.StationBean.StationEntry;

public class StationDAO {
        
        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;

        }


        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";

                Connection conn = null;
                Statement stmt = null;
                ResultSet res = null;
                StationEntry result;

                try {
                        conn = DBConnection.getConnection();

                        stmt = conn.createStatement();
                        res = stmt.executeQuery(SQL);
                        
                        if (res.next()) {
                                result = convertSingleRow(res);
                        } else {
                                throw new NostationException();
                        }
                } finally {
                        if (res != null)
                                res.close();
                        if (stmt != null)
                                stmt.close();
                        if (conn != null)
                                conn.close();
                }

                return result;
        }
        
        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();
                }
                
        }

        /*
         * 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(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 ";


                StationBean result;
                Connection conn = null;
                PreparedStatement stmt = null;
                ResultSet res = null;
                try {
                        conn = DBConnection.getConnection();
                        stmt = conn.prepareStatement(SQL);

                        stmt.setString(1, name + "%");
                        stmt.setString(2, name + "%");

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

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

        //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(double latitude, double longitude, 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;


                StationBean result;
                Connection conn = null;
                PreparedStatement stmt = null;
                ResultSet res = null;
                try {
                        conn = DBConnection.getConnection();
                        stmt = conn.prepareStatement(SQL);
                        stmt.setDouble(1, latitude);
                        stmt.setDouble(2, longitude);
                        if (geolimit == true) {
                                stmt.setDouble(3, latitude);
                                stmt.setDouble(4, longitude);
                        }
                        res = stmt.executeQuery();
                        result = convertResultset(res);
                
                } finally {
                        if (res != null)
                                res.close();
                        if (stmt != null)
                                stmt.close();
                        if (conn!= null)
                                conn.close();
                }
                return result;
        }
        
        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 ";

                Connection conn = null;
                Statement stmt = null;
                ResultSet res = null;
                StationBean result;

                try {
                        conn = DBConnection.getConnection();
                        stmt = conn.createStatement();
                        res = stmt.executeQuery(SQL);
                        result = convertResultset(res);
                } finally {
                        if (res != null)
                                res.close();
                        if (stmt != null)
                                stmt.close();
                        if (conn!= null)
                                conn.close();
                }

                return result;

        }
        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;
        }

        public int getIdByName(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 ";

                StationBean result;
                Connection conn = null;
                PreparedStatement stmt = null;
                ResultSet res = null;
                try {
                        conn = DBConnection.getConnection();
                        stmt = conn.prepareStatement(SQL);

                        stmt.setString(1, name );

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

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

                if (result.entries.size() == 1) {
                        return result.entries.get(0).getId();
                } else {
                        return -1;
                }
        }
}
1	package dk.thoerup.traininfoservice;
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.StationBean.StationEntry;
13
14	public class StationDAO {
15
16	public static class NostationException extends Exception {
17	private static final long serialVersionUID = 1L;
18	}
19
20	final static int LOCATION_LIMIT = 8;
21	static final Logger logger = Logger.getLogger(StationDAO.class.getName());
22
23
24	private StationEntry convertSingleRow(ResultSet res) throws SQLException {
25	StationEntry station = new StationEntry();
26
27	station.setId( res.getInt(1) );
28	station.setName( res.getString(2) );
29	station.setLatitude( res.getDouble(3) );
30	station.setLongitude( res.getDouble(4) );
31	station.setRegional( res.getString(5) );
32	station.setStrain( res.getString(6) );
33	station.setMetro( res.getString(7) );
34	station.setAddress( res.getString(8) );
35	station.setCalcdist( (int)res.getDouble(9) );
36
37	station.setIsRegional( station.getRegional() != null );
38	station.setIsStrain( station.getStrain() != null );
39	station.setIsMetro( station.getMetro() != null );
40
41	return station;
42	}
43
44	private StationBean convertResultset(ResultSet res) throws SQLException {
45	StationBean stations = new StationBean();
46	while (res.next()) {
47	stations.entries.add( convertSingleRow(res) );
48	}
49	return stations;
50
51	}
52
53
54	public StationEntry getById(int id) throws SQLException,NostationException {
55	String SQL = "SELECT id,name,latitude,longitude,stationcode_fjrn,stationcode_stog,stationcode_metro,address,0.0 " +
56	"FROM trainstations WHERE id=" + id + " AND enabled=true";
57
58	Connection conn = null;
59	Statement stmt = null;
60	ResultSet res = null;
61	StationEntry result;
62
63	try {
64	conn = DBConnection.getConnection();
65
66	stmt = conn.createStatement();
67	res = stmt.executeQuery(SQL);
68
69	if (res.next()) {
70	result = convertSingleRow(res);
71	} else {
72	throw new NostationException();
73	}
74	} finally {
75	if (res != null)
76	res.close();
77	if (stmt != null)
78	stmt.close();
79	if (conn != null)
80	conn.close();
81	}
82
83	return result;
84	}
85
86	public StationBean dumpAll() throws SQLException {
87
88	String SQL = "SELECT id,name,latitude,longitude,stationcode_fjrn,stationcode_stog,stationcode_metro,address,0.0,aliases " +
89	"FROM trainstations WHERE enabled = true ORDER BY id";
90
91	Connection conn = null;
92	Statement stmt = null;
93	ResultSet res = null;
94
95
96	try {
97	conn = DBConnection.getConnection();
98
99	stmt = conn.createStatement();
100	res = stmt.executeQuery(SQL);
101
102	// Does mostly the same as convertResultset()
103	StationBean stations = new StationBean();
104	while (res.next()) {
105	StationEntry entry = convertSingleRow(res);
106
107	Array arr = res.getArray(10);
108	if (arr != null) {
109	String[] aliases = (String[]) arr.getArray();
110	entry.setAliases(aliases);
111	}
112
113	stations.entries.add( entry );
114
115	}
116	return stations;
117
118
119	} finally {
120	if (res != null)
121	res.close();
122	if (stmt != null)
123	stmt.close();
124	if (conn != null)
125	conn.close();
126	}
127
128	}
129
130	/*
131	* 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) )
132	* create function rlike(text,text) returns bool as
133	* 'select $2 ilike $1' language sql strict immutable;
134	* create operator ~~~ (procedure = rlike, leftarg = text, rightarg = text, commutator = ~~);
135	*/
136	public StationBean getByName(String name) throws SQLException {
137	String SQL = "SELECT id,name,latitude,longitude,stationcode_fjrn,stationcode_stog, stationcode_metro, address, 0.0 " +
138	"FROM trainstations " +
139	"WHERE (name ILIKE ? OR ? ~~~ ANY(aliases)) AND enabled = true " +
140	"ORDER BY name ";
141
142
143	StationBean result;
144	Connection conn = null;
145	PreparedStatement stmt = null;
146	ResultSet res = null;
147	try {
148	conn = DBConnection.getConnection();
149	stmt = conn.prepareStatement(SQL);
150
151	stmt.setString(1, name + "%");
152	stmt.setString(2, name + "%");
153
154	res = stmt.executeQuery();
155	result = convertResultset(res);
156
157	} finally {
158	if (res != null)
159	res.close();
160	if (stmt != null)
161	stmt.close();
162	if (conn!= null)
163	conn.close();
164	}
165	return result;
166	}
167
168	//the "hack" with max 0.4 degrees latitude and 0.75 degrees longitude is only valid since we only service danish trains,
169	// in denmark 0.4dg latitude ~ 44km, 0.75dg longitude ~ 47km
170
171	// the ultra fast method (and only slightly inaccurate as long as we only cover a limited geographically area)
172	// is using an aproximation of the length of 1 latitude degree and 1 longitude degree and just use pythagoras to
173	// calculate the distance:
174	// sqrt( power(abs(latitude-?)111320, 2) + power(abs(longitude-?)63000,2) )::int as calcdist
175
176	public StationBean getByLocationWorker(double latitude, double longitude, boolean geolimit) throws SQLException {
177
178	String limitExpression = (geolimit == true) ? "AND abs(latitude-?)<0.4 AND abs(longitude-?)<0.75 " : "";
179
180	String SQL = "SELECT id,name,latitude,longitude,stationcode_fjrn,stationcode_stog, stationcode_metro, address, " +
181	"earth_distance( earth_coord, ll_to_earth(?,?))::int AS calcdist " +
182	"FROM trainstations " +
183	"WHERE enabled = true " + limitExpression +
184	"ORDER BY calcdist ASC " +
185	"LIMIT " + LOCATION_LIMIT;
186
187
188
189	StationBean result;
190	Connection conn = null;
191	PreparedStatement stmt = null;
192	ResultSet res = null;
193	try {
194	conn = DBConnection.getConnection();
195	stmt = conn.prepareStatement(SQL);
196	stmt.setDouble(1, latitude);
197	stmt.setDouble(2, longitude);
198	if (geolimit == true) {
199	stmt.setDouble(3, latitude);
200	stmt.setDouble(4, longitude);
201	}
202	res = stmt.executeQuery();
203	result = convertResultset(res);
204
205	} finally {
206	if (res != null)
207	res.close();
208	if (stmt != null)
209	stmt.close();
210	if (conn!= null)
211	conn.close();
212	}
213	return result;
214	}
215
216	public StationBean getByLocation(double latitude, double longitude) throws SQLException {
217	StationBean result = getByLocationWorker(latitude, longitude, true);
218
219	if (result.entries.size() < LOCATION_LIMIT) { //failover
220	logger.info("getByLocation failover: " +latitude + "," + longitude);
221
222	result = getByLocationWorker(latitude, longitude, false);
223	}
224
225	return result;
226	}
227
228
229
230	public StationBean getByList(String list) throws SQLException {
231	String SQL = "SELECT id,name,latitude,longitude,stationcode_fjrn,stationcode_stog,stationcode_metro, address,0.0 " +
232	"FROM trainstations " +
233	"WHERE id IN " + list + " AND enabled = true " +
234	"ORDER BY name ";
235
236	Connection conn = null;
237	Statement stmt = null;
238	ResultSet res = null;
239	StationBean result;
240
241	try {
242	conn = DBConnection.getConnection();
243	stmt = conn.createStatement();
244	res = stmt.executeQuery(SQL);
245	result = convertResultset(res);
246	} finally {
247	if (res != null)
248	res.close();
249	if (stmt != null)
250	stmt.close();
251	if (conn!= null)
252	conn.close();
253	}
254
255	return result;
256
257	}
258	public static String getStationName(int stationID) {
259	String station = "";
260
261	Connection conn = null;
262	try {
263	conn = DBConnection.getConnection();
264	Statement stmt = conn.createStatement();
265	ResultSet rs = stmt.executeQuery("SELECT name FROM trainstations WHERE id=" + stationID);
266	if (rs.next()) {
267	station = rs.getString(1);
268	}
269
270	} catch (Exception e) {
271	} finally {
272	try {
273	if (conn != null && !conn.isClosed())
274	conn.close();
275	} catch (Exception e) {}
276	}
277
278	return station;
279	}
280
281	public int getIdByName(String name) throws SQLException {
282	String SQL = "SELECT id,name,latitude,longitude,stationcode_fjrn,stationcode_stog, stationcode_metro, address, 0.0 " +
283	"FROM trainstations " +
284	"WHERE name = ? AND enabled = true " +
285	"LIMIT 1 ";
286
287	StationBean result;
288	Connection conn = null;
289	PreparedStatement stmt = null;
290	ResultSet res = null;
291	try {
292	conn = DBConnection.getConnection();
293	stmt = conn.prepareStatement(SQL);
294
295	stmt.setString(1, name );
296
297	res = stmt.executeQuery();
298	result = convertResultset(res);
299
300	} finally {
301	if (res != null)
302	res.close();
303	if (stmt != null)
304	stmt.close();
305	if (conn!= null)
306	conn.close();
307	}
308
309	if (result.entries.size() == 1) {
310	return result.entries.get(0).getId();
311	} else {
312	return -1;
313	}
314	}
315	}