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.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;
        }

        /*
         * 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.android.traininfo.common.StationBean;
11	import dk.thoerup.android.traininfo.common.StationBean.StationEntry;
12
13	public class StationDAO {
14	final static int LOCATION_LIMIT = 8;
15	static final Logger logger = Logger.getLogger(StationDAO.class.getName());
16
17
18	private StationEntry convertSingleRow(ResultSet res) throws SQLException {
19	StationEntry station = new StationEntry();
20
21	station.setId( res.getInt(1) );
22	station.setName( res.getString(2) );
23	station.setLatitude( res.getDouble(3) );
24	station.setLongitude( res.getDouble(4) );
25	station.setRegional( res.getString(5) );
26	station.setStrain( res.getString(6) );
27	station.setMetro( res.getString(7) );
28	station.setAddress( res.getString(8) );
29	station.setCalcdist( (int)res.getDouble(9) );
30
31	station.setIsRegional( station.getRegional() != null );
32	station.setIsStrain( station.getStrain() != null );
33	station.setIsMetro( station.getMetro() != null );
34
35	return station;
36	}
37
38	private StationBean convertResultset(ResultSet res) throws SQLException {
39	StationBean stations = new StationBean();
40	while (res.next()) {
41	stations.entries.add( convertSingleRow(res) );
42	}
43	return stations;
44
45	}
46
47
48	public StationEntry getById(int id) throws SQLException {
49	String SQL = "SELECT id,name,latitude,longitude,stationcode_fjrn,stationcode_stog,stationcode_metro,address,0.0 " +
50	"FROM trainstations WHERE id=" + id + " AND enabled=true";
51
52	Connection conn = null;
53	Statement stmt = null;
54	ResultSet res = null;
55	StationEntry result;
56
57	try {
58	conn = DBConnection.getConnection();
59
60	stmt = conn.createStatement();
61	res = stmt.executeQuery(SQL);
62	res.next();
63	result = convertSingleRow(res);
64	} finally {
65	if (res != null)
66	res.close();
67	if (stmt != null)
68	stmt.close();
69	if (conn != null)
70	conn.close();
71	}
72
73	return result;
74	}
75
76	/*
77	* 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) )
78	* create function rlike(text,text) returns bool as
79	* 'select $2 ilike $1' language sql strict immutable;
80	* create operator ~~~ (procedure = rlike, leftarg = text, rightarg = text, commutator = ~~);
81	*/
82	public StationBean getByName(String name) throws SQLException {
83	String SQL = "SELECT id,name,latitude,longitude,stationcode_fjrn,stationcode_stog, stationcode_metro, address, 0.0 " +
84	"FROM trainstations " +
85	"WHERE (name ILIKE ? OR ? ~~~ ANY(aliases)) AND enabled = true " +
86	"ORDER BY name ";
87
88
89	StationBean result;
90	Connection conn = null;
91	PreparedStatement stmt = null;
92	ResultSet res = null;
93	try {
94	conn = DBConnection.getConnection();
95	stmt = conn.prepareStatement(SQL);
96
97	stmt.setString(1, name + "%");
98	stmt.setString(2, name + "%");
99
100	res = stmt.executeQuery();
101	result = convertResultset(res);
102
103	} finally {
104	if (res != null)
105	res.close();
106	if (stmt != null)
107	stmt.close();
108	if (conn!= null)
109	conn.close();
110	}
111	return result;
112	}
113
114	//the "hack" with max 0.4 degrees latitude and 0.75 degrees longitude is only valid since we only service danish trains,
115	// in denmark 0.4dg latitude ~ 44km, 0.75dg longitude ~ 47km
116
117	// the ultra fast method (and only slightly inaccurate as long as we only cover a limited geographically area)
118	// is using an aproximation of the length of 1 latitude degree and 1 longitude degree and just use pythagoras to
119	// calculate the distance:
120	// sqrt( power(abs(latitude-?)111320, 2) + power(abs(longitude-?)63000,2) )::int as calcdist
121
122	public StationBean getByLocationWorker(double latitude, double longitude, boolean geolimit) throws SQLException {
123
124	String limitExpression = (geolimit == true) ? "AND abs(latitude-?)<0.4 AND abs(longitude-?)<0.75 " : "";
125
126	String SQL = "SELECT id,name,latitude,longitude,stationcode_fjrn,stationcode_stog, stationcode_metro, address, " +
127	"earth_distance( earth_coord, ll_to_earth(?,?))::int AS calcdist " +
128	"FROM trainstations " +
129	"WHERE enabled = true " + limitExpression +
130	"ORDER BY calcdist ASC " +
131	"LIMIT " + LOCATION_LIMIT;
132
133
134
135	StationBean result;
136	Connection conn = null;
137	PreparedStatement stmt = null;
138	ResultSet res = null;
139	try {
140	conn = DBConnection.getConnection();
141	stmt = conn.prepareStatement(SQL);
142	stmt.setDouble(1, latitude);
143	stmt.setDouble(2, longitude);
144	if (geolimit == true) {
145	stmt.setDouble(3, latitude);
146	stmt.setDouble(4, longitude);
147	}
148	res = stmt.executeQuery();
149	result = convertResultset(res);
150
151	} finally {
152	if (res != null)
153	res.close();
154	if (stmt != null)
155	stmt.close();
156	if (conn!= null)
157	conn.close();
158	}
159	return result;
160	}
161
162	public StationBean getByLocation(double latitude, double longitude) throws SQLException {
163	StationBean result = getByLocationWorker(latitude, longitude, true);
164
165	if (result.entries.size() < LOCATION_LIMIT) { //failover
166	logger.info("getByLocation failover: " +latitude + "," + longitude);
167
168	result = getByLocationWorker(latitude, longitude, false);
169	}
170
171	return result;
172	}
173
174
175
176	public StationBean getByList(String list) throws SQLException {
177	String SQL = "SELECT id,name,latitude,longitude,stationcode_fjrn,stationcode_stog,stationcode_metro, address,0.0 " +
178	"FROM trainstations " +
179	"WHERE id IN " + list + " AND enabled = true " +
180	"ORDER BY name ";
181
182	Connection conn = null;
183	Statement stmt = null;
184	ResultSet res = null;
185	StationBean result;
186
187	try {
188	conn = DBConnection.getConnection();
189	stmt = conn.createStatement();
190	res = stmt.executeQuery(SQL);
191	result = convertResultset(res);
192	} finally {
193	if (res != null)
194	res.close();
195	if (stmt != null)
196	stmt.close();
197	if (conn!= null)
198	conn.close();
199	}
200
201	return result;
202
203	}
204	public static String getStationName(int stationID) {
205	String station = "";
206
207	Connection conn = null;
208	try {
209	conn = DBConnection.getConnection();
210	Statement stmt = conn.createStatement();
211	ResultSet rs = stmt.executeQuery("SELECT name FROM trainstations WHERE id=" + stationID);
212	if (rs.next()) {
213	station = rs.getString(1);
214	}
215
216	} catch (Exception e) {
217	} finally {
218	try {
219	if (conn != null && !conn.isClosed())
220	conn.close();
221	} catch (Exception e) {}
222	}
223
224	return station;
225	}
226
227	public int getIdByName(String name) throws SQLException {
228	String SQL = "SELECT id,name,latitude,longitude,stationcode_fjrn,stationcode_stog, stationcode_metro, address, 0.0 " +
229	"FROM trainstations " +
230	"WHERE name = ? AND enabled = true " +
231	"LIMIT 1 ";
232
233	StationBean result;
234	Connection conn = null;
235	PreparedStatement stmt = null;
236	ResultSet res = null;
237	try {
238	conn = DBConnection.getConnection();
239	stmt = conn.prepareStatement(SQL);
240
241	stmt.setString(1, name );
242
243	res = stmt.executeQuery();
244	result = convertResultset(res);
245
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	if (result.entries.size() == 1) {
256	return result.entries.get(0).getId();
257	} else {
258	return -1;
259	}
260	}
261	}