thoerup/traininfoservice/StationDAO.java

package dk.thoerup.traininfoservice;

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.traininfoservice.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;
        }

        /*
         * 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.Connection;
4	import java.sql.PreparedStatement;
5	import java.sql.ResultSet;
6	import java.sql.SQLException;
7	import java.sql.Statement;
8	import java.util.logging.Logger;
9
10	import dk.thoerup.traininfoservice.StationBean.StationEntry;
11
12	public class StationDAO {
13	final static int LOCATION_LIMIT = 8;
14	static final Logger logger = Logger.getLogger(StationDAO.class.getName());
15
16
17	private StationEntry convertSingleRow(ResultSet res) throws SQLException {
18	StationEntry station = new StationEntry();
19
20	station.setId( res.getInt(1) );
21	station.setName( res.getString(2) );
22	station.setLatitude( res.getDouble(3) );
23	station.setLongitude( res.getDouble(4) );
24	station.setRegional( res.getString(5) );
25	station.setStrain( res.getString(6) );
26	station.setMetro( res.getString(7) );
27	station.setAddress( res.getString(8) );
28	station.setCalcdist( (int)res.getDouble(9) );
29
30	station.setIsRegional( station.getRegional() != null );
31	station.setIsStrain( station.getStrain() != null );
32	station.setIsMetro( station.getMetro() != null );
33
34	return station;
35	}
36
37	private StationBean convertResultset(ResultSet res) throws SQLException {
38	StationBean stations = new StationBean();
39	while (res.next()) {
40	stations.entries.add( convertSingleRow(res) );
41	}
42	return stations;
43
44	}
45
46
47	public StationEntry getById(int id) throws SQLException {
48	String SQL = "SELECT id,name,latitude,longitude,stationcode_fjrn,stationcode_stog,stationcode_metro,address,0.0 " +
49	"FROM trainstations WHERE id=" + id + " AND enabled=true";
50
51	Connection conn = null;
52	Statement stmt = null;
53	ResultSet res = null;
54	StationEntry result;
55
56	try {
57	conn = DBConnection.getConnection();
58
59	stmt = conn.createStatement();
60	res = stmt.executeQuery(SQL);
61	res.next();
62	result = convertSingleRow(res);
63	} finally {
64	if (res != null)
65	res.close();
66	if (stmt != null)
67	stmt.close();
68	if (conn != null)
69	conn.close();
70	}
71
72	return result;
73	}
74
75	/*
76	* 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) )
77	* create function rlike(text,text) returns bool as
78	* 'select $2 ilike $1' language sql strict immutable;
79	* create operator ~~~ (procedure = rlike, leftarg = text, rightarg = text, commutator = ~~);
80	*/
81	public StationBean getByName(String name) throws SQLException {
82	String SQL = "SELECT id,name,latitude,longitude,stationcode_fjrn,stationcode_stog, stationcode_metro, address, 0.0 " +
83	"FROM trainstations " +
84	"WHERE (name ILIKE ? OR ? ~~~ ANY(aliases)) AND enabled = true " +
85	"ORDER BY name ";
86
87
88	StationBean result;
89	Connection conn = null;
90	PreparedStatement stmt = null;
91	ResultSet res = null;
92	try {
93	conn = DBConnection.getConnection();
94	stmt = conn.prepareStatement(SQL);
95
96	stmt.setString(1, name + "%");
97	stmt.setString(2, name + "%");
98
99	res = stmt.executeQuery();
100	result = convertResultset(res);
101
102	} finally {
103	if (res != null)
104	res.close();
105	if (stmt != null)
106	stmt.close();
107	if (conn!= null)
108	conn.close();
109	}
110	return result;
111	}
112
113	//the "hack" with max 0.4 degrees latitude and 0.75 degrees longitude is only valid since we only service danish trains,
114	// in denmark 0.4dg latitude ~ 44km, 0.75dg longitude ~ 47km
115
116	// the ultra fast method (and only slightly inaccurate as long as we only cover a limited geographically area)
117	// is using an aproximation of the length of 1 latitude degree and 1 longitude degree and just use pythagoras to
118	// calculate the distance:
119	// sqrt( power(abs(latitude-?)111320, 2) + power(abs(longitude-?)63000,2) )::int as calcdist
120
121	public StationBean getByLocationWorker(double latitude, double longitude, boolean geolimit) throws SQLException {
122
123	String limitExpression = (geolimit == true) ? "AND abs(latitude-?)<0.4 AND abs(longitude-?)<0.75 " : "";
124
125	String SQL = "SELECT id,name,latitude,longitude,stationcode_fjrn,stationcode_stog, stationcode_metro, address, " +
126	"earth_distance( earth_coord, ll_to_earth(?,?))::int AS calcdist " +
127	"FROM trainstations " +
128	"WHERE enabled = true " + limitExpression +
129	"ORDER BY calcdist ASC " +
130	"LIMIT " + LOCATION_LIMIT;
131
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	stmt.setDouble(1, latitude);
142	stmt.setDouble(2, longitude);
143	if (geolimit == true) {
144	stmt.setDouble(3, latitude);
145	stmt.setDouble(4, longitude);
146	}
147	res = stmt.executeQuery();
148	result = convertResultset(res);
149
150	} finally {
151	if (res != null)
152	res.close();
153	if (stmt != null)
154	stmt.close();
155	if (conn!= null)
156	conn.close();
157	}
158	return result;
159	}
160
161	public StationBean getByLocation(double latitude, double longitude) throws SQLException {
162	StationBean result = getByLocationWorker(latitude, longitude, true);
163
164	if (result.entries.size() < LOCATION_LIMIT) { //failover
165	logger.info("getByLocation failover: " +latitude + "," + longitude);
166
167	result = getByLocationWorker(latitude, longitude, false);
168	}
169
170	return result;
171	}
172
173
174
175	public StationBean getByList(String list) throws SQLException {
176	String SQL = "SELECT id,name,latitude,longitude,stationcode_fjrn,stationcode_stog,stationcode_metro, address,0.0 " +
177	"FROM trainstations " +
178	"WHERE id IN " + list + " AND enabled = true " +
179	"ORDER BY name ";
180
181	Connection conn = null;
182	Statement stmt = null;
183	ResultSet res = null;
184	StationBean result;
185
186	try {
187	conn = DBConnection.getConnection();
188	stmt = conn.createStatement();
189	res = stmt.executeQuery(SQL);
190	result = convertResultset(res);
191	} finally {
192	if (res != null)
193	res.close();
194	if (stmt != null)
195	stmt.close();
196	if (conn!= null)
197	conn.close();
198	}
199
200	return result;
201
202	}
203	public static String getStationName(int stationID) {
204	String station = "";
205
206	Connection conn = null;
207	try {
208	conn = DBConnection.getConnection();
209	Statement stmt = conn.createStatement();
210	ResultSet rs = stmt.executeQuery("SELECT name FROM trainstations WHERE id=" + stationID);
211	if (rs.next()) {
212	station = rs.getString(1);
213	}
214
215	} catch (Exception e) {
216	} finally {
217	try {
218	if (conn != null && !conn.isClosed())
219	conn.close();
220	} catch (Exception e) {}
221	}
222
223	return station;
224	}
225
226	public int getIdByName(String name) throws SQLException {
227	String SQL = "SELECT id,name,latitude,longitude,stationcode_fjrn,stationcode_stog, stationcode_metro, address, 0.0 " +
228	"FROM trainstations " +
229	"WHERE name = ? AND enabled = true " +
230	"LIMIT 1 ";
231
232	StationBean result;
233	Connection conn = null;
234	PreparedStatement stmt = null;
235	ResultSet res = null;
236	try {
237	conn = DBConnection.getConnection();
238	stmt = conn.prepareStatement(SQL);
239
240	stmt.setString(1, name );
241
242	res = stmt.executeQuery();
243	result = convertResultset(res);
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	if (result.entries.size() == 1) {
255	return result.entries.get(0).getId();
256	} else {
257	return -1;
258	}
259	}
260	}