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