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.ArrayList;
import java.util.List;

public class StationDAO {
        final static int LOCATION_LIMIT = 5;
        
        private StationBean convertSingleRow(ResultSet res) throws SQLException {
                StationBean station = new StationBean();

                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) );

                return station;
        }

        private List<StationBean> convertResultset(ResultSet res) throws SQLException {
                List<StationBean> stations = new ArrayList<StationBean>();
                while (res.next()) {
                        stations.add( convertSingleRow(res) );
                }
                return stations;

        }


        public StationBean 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;
                StationBean 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 List<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 ";


                List<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 0.5 degrees latitude and 0.9 degrees longitude is only valid since we only service danish trains,
        // in denmark 0.5dg latitude ~ 55km, 0.9dg longitude ~ 57km

        // 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 List<StationBean> getByLocationWorker(double latitude, double longitude, boolean geolimit) throws SQLException {
                
                String limitExpression = geolimit == true ? "AND abs(latitude-?)<0.5 AND abs(longitude-?)<0.9 " : "";
                
                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;


                List<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 List<StationBean> getByLocation(double latitude, double longitude) throws SQLException {
                List<StationBean> result = getByLocationWorker(latitude, longitude, true);
                
                if (result.size() < LOCATION_LIMIT) { //failover
                        result = getByLocationWorker(latitude, longitude, false);
                }
                
                return result;
        }
        
        
        public List<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;
                List<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 ";

                List<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.size() == 1) {
                        return result.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.ArrayList;
9	import java.util.List;
10
11	public class StationDAO {
12	final static int LOCATION_LIMIT = 5;
13
14	private StationBean convertSingleRow(ResultSet res) throws SQLException {
15	StationBean station = new StationBean();
16
17	station.setId( res.getInt(1) );
18	station.setName( res.getString(2) );
19	station.setLatitude( res.getDouble(3) );
20	station.setLongitude( res.getDouble(4) );
21	station.setRegional( res.getString(5) );
22	station.setStrain( res.getString(6) );
23	station.setMetro( res.getString(7) );
24	station.setAddress( res.getString(8) );
25	station.setCalcdist( (int)res.getDouble(9) );
26
27	return station;
28	}
29
30	private List<StationBean> convertResultset(ResultSet res) throws SQLException {
31	List<StationBean> stations = new ArrayList<StationBean>();
32	while (res.next()) {
33	stations.add( convertSingleRow(res) );
34	}
35	return stations;
36
37	}
38
39
40	public StationBean getById(int id) throws SQLException {
41	String SQL = "SELECT id,name,latitude,longitude,stationcode_fjrn,stationcode_stog,stationcode_metro,address,0.0 " +
42	"FROM trainstations WHERE id=" + id + " AND enabled=true";
43
44	Connection conn = null;
45	Statement stmt = null;
46	ResultSet res = null;
47	StationBean result;
48
49	try {
50	conn = DBConnection.getConnection();
51
52	stmt = conn.createStatement();
53	res = stmt.executeQuery(SQL);
54	res.next();
55	result = convertSingleRow(res);
56	} finally {
57	if (res != null)
58	res.close();
59	if (stmt != null)
60	stmt.close();
61	if (conn != null)
62	conn.close();
63	}
64
65	return result;
66	}
67
68	/*
69	* 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) )
70	* create function rlike(text,text) returns bool as
71	* 'select $2 ilike $1' language sql strict immutable;
72	* create operator ~~~ (procedure = rlike, leftarg = text, rightarg = text, commutator = ~~);
73	*/
74	public List<StationBean> getByName(String name) throws SQLException {
75	String SQL = "SELECT id,name,latitude,longitude,stationcode_fjrn,stationcode_stog, stationcode_metro, address, 0.0 " +
76	"FROM trainstations " +
77	"WHERE (name ILIKE ? OR ? ~~~ ANY(aliases)) AND enabled = true " +
78	"ORDER BY name ";
79
80
81	List<StationBean> result;
82	Connection conn = null;
83	PreparedStatement stmt = null;
84	ResultSet res = null;
85	try {
86	conn = DBConnection.getConnection();
87	stmt = conn.prepareStatement(SQL);
88
89	stmt.setString(1, name + "%");
90	stmt.setString(2, name + "%");
91
92	res = stmt.executeQuery();
93	result = convertResultset(res);
94
95	} finally {
96	if (res != null)
97	res.close();
98	if (stmt != null)
99	stmt.close();
100	if (conn!= null)
101	conn.close();
102	}
103	return result;
104	}
105
106	//the "hack" with max 0.5 degrees latitude and 0.9 degrees longitude is only valid since we only service danish trains,
107	// in denmark 0.5dg latitude ~ 55km, 0.9dg longitude ~ 57km
108
109	// the ultra fast method (and only slightly inaccurate as long as we only cover a limited geographically area)
110	// is using an aproximation of the length of 1 latitude degree and 1 longitude degree and just use pythagoras to
111	// calculate the distance:
112	// sqrt( power(abs(latitude-?)111320, 2) + power(abs(longitude-?)63000,2) )::int as calcdist
113
114	public List<StationBean> getByLocationWorker(double latitude, double longitude, boolean geolimit) throws SQLException {
115
116	String limitExpression = geolimit == true ? "AND abs(latitude-?)<0.5 AND abs(longitude-?)<0.9 " : "";
117
118	String SQL = "SELECT id,name,latitude,longitude,stationcode_fjrn,stationcode_stog, stationcode_metro, address, " +
119	"earth_distance( earth_coord, ll_to_earth(?,?))::int AS calcdist " +
120	"FROM trainstations " +
121	"WHERE enabled = true " + limitExpression +
122	"ORDER BY calcdist ASC " +
123	"LIMIT " + LOCATION_LIMIT;
124
125
126
127	List<StationBean> result;
128	Connection conn = null;
129	PreparedStatement stmt = null;
130	ResultSet res = null;
131	try {
132	conn = DBConnection.getConnection();
133	stmt = conn.prepareStatement(SQL);
134	stmt.setDouble(1, latitude);
135	stmt.setDouble(2, longitude);
136	if (geolimit == true) {
137	stmt.setDouble(3, latitude);
138	stmt.setDouble(4, longitude);
139	}
140	res = stmt.executeQuery();
141	result = convertResultset(res);
142
143	} finally {
144	if (res != null)
145	res.close();
146	if (stmt != null)
147	stmt.close();
148	if (conn!= null)
149	conn.close();
150	}
151	return result;
152	}
153
154	public List<StationBean> getByLocation(double latitude, double longitude) throws SQLException {
155	List<StationBean> result = getByLocationWorker(latitude, longitude, true);
156
157	if (result.size() < LOCATION_LIMIT) { //failover
158	result = getByLocationWorker(latitude, longitude, false);
159	}
160
161	return result;
162	}
163
164
165
166	public List<StationBean> getByList(String list) throws SQLException {
167	String SQL = "SELECT id,name,latitude,longitude,stationcode_fjrn,stationcode_stog,stationcode_metro, address,0.0 " +
168	"FROM trainstations " +
169	"WHERE id IN " + list + " AND enabled = true " +
170	"ORDER BY name ";
171
172	Connection conn = null;
173	Statement stmt = null;
174	ResultSet res = null;
175	List<StationBean> result;
176
177	try {
178	conn = DBConnection.getConnection();
179	stmt = conn.createStatement();
180	res = stmt.executeQuery(SQL);
181	result = convertResultset(res);
182	} finally {
183	if (res != null)
184	res.close();
185	if (stmt != null)
186	stmt.close();
187	if (conn!= null)
188	conn.close();
189	}
190
191	return result;
192
193	}
194	public static String getStationName(int stationID) {
195	String station = "";
196
197	Connection conn = null;
198	try {
199	conn = DBConnection.getConnection();
200	Statement stmt = conn.createStatement();
201	ResultSet rs = stmt.executeQuery("SELECT name FROM trainstations WHERE id=" + stationID);
202	if (rs.next()) {
203	station = rs.getString(1);
204	}
205
206	} catch (Exception e) {
207	} finally {
208	try {
209	if (conn != null && !conn.isClosed())
210	conn.close();
211	} catch (Exception e) {}
212	}
213
214	return station;
215	}
216
217	public int getIdByName(String name) throws SQLException {
218	String SQL = "SELECT id,name,latitude,longitude,stationcode_fjrn,stationcode_stog, stationcode_metro, address, 0.0 " +
219	"FROM trainstations " +
220	"WHERE name = ? AND enabled = true " +
221	"LIMIT 1 ";
222
223	List<StationBean> result;
224	Connection conn = null;
225	PreparedStatement stmt = null;
226	ResultSet res = null;
227	try {
228	conn = DBConnection.getConnection();
229	stmt = conn.prepareStatement(SQL);
230
231	stmt.setString(1, name );
232
233	res = stmt.executeQuery();
234	result = convertResultset(res);
235
236	} finally {
237	if (res != null)
238	res.close();
239	if (stmt != null)
240	stmt.close();
241	if (conn!= null)
242	conn.close();
243	}
244
245	if (result.size() == 1) {
246	return result.get(0).getId();
247	} else {
248	return -1;
249	}
250	}
251	}