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 {
        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 1.5 degrees latitude and 2.5 degrees longitude is only valid since we only service danish trains
        // in denmark 1.5dg latitude ~ 165km, 2.5dg longitude ~ 155km
        
        // 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> getByLocation(double latitude, double longitude) throws SQLException {
                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 AND abs(latitude-?)<1.5 AND abs(longitude-?)<2.5 " +
                                         "ORDER BY calcdist ASC " + 
                                         "LIMIT 4 ";
                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);
                        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> 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;
         }
}
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	private StationBean convertSingleRow(ResultSet res) throws SQLException {
13	StationBean station = new StationBean();
14
15	station.setId( res.getInt(1) );
16	station.setName( res.getString(2) );
17	station.setLatitude( res.getDouble(3) );
18	station.setLongitude( res.getDouble(4) );
19	station.setRegional( res.getString(5) );
20	station.setStrain( res.getString(6) );
21	station.setMetro( res.getString(7) );
22	station.setAddress( res.getString(8) );
23	station.setCalcdist( (int)res.getDouble(9) );
24
25	return station;
26	}
27
28	private List<StationBean> convertResultset(ResultSet res) throws SQLException {
29	List<StationBean> stations = new ArrayList<StationBean>();
30	while (res.next()) {
31	stations.add( convertSingleRow(res) );
32	}
33	return stations;
34
35	}
36
37
38	public StationBean getById(int id) throws SQLException {
39	String SQL = "SELECT id,name,latitude,longitude,stationcode_fjrn,stationcode_stog,stationcode_metro,address,0.0 " +
40	"FROM trainstations WHERE id=" + id + " AND enabled=true";
41
42	Connection conn = null;
43	Statement stmt = null;
44	ResultSet res = null;
45	StationBean result;
46
47	try {
48	conn = DBConnection.getConnection();
49
50	stmt = conn.createStatement();
51	res = stmt.executeQuery(SQL);
52	res.next();
53	result = convertSingleRow(res);
54	} finally {
55	if (res != null)
56	res.close();
57	if (stmt != null)
58	stmt.close();
59	if (conn != null)
60	conn.close();
61	}
62
63	return result;
64	}
65
66	/*
67	* 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) )
68	* create function rlike(text,text) returns bool as
69	* 'select $2 ilike $1' language sql strict immutable;
70	* create operator ~~~ (procedure = rlike, leftarg = text, rightarg = text, commutator = ~~);
71	*/
72	public List<StationBean> getByName(String name) throws SQLException {
73	String SQL = "SELECT id,name,latitude,longitude,stationcode_fjrn,stationcode_stog, stationcode_metro, address, 0.0 " +
74	"FROM trainstations " +
75	"WHERE (name ILIKE ? OR ? ~~~ ANY(aliases)) AND enabled = true " +
76	"ORDER BY name ";
77
78
79	List<StationBean> result;
80	Connection conn = null;
81	PreparedStatement stmt = null;
82	ResultSet res = null;
83	try {
84	conn = DBConnection.getConnection();
85	stmt = conn.prepareStatement(SQL);
86
87	stmt.setString(1, name + "%");
88	stmt.setString(2, name + "%");
89
90	res = stmt.executeQuery();
91	result = convertResultset(res);
92
93	} finally {
94	if (res != null)
95	res.close();
96	if (stmt != null)
97	stmt.close();
98	if (conn!= null)
99	conn.close();
100	}
101	return result;
102	}
103
104	//the "hack" with max 1.5 degrees latitude and 2.5 degrees longitude is only valid since we only service danish trains
105	// in denmark 1.5dg latitude ~ 165km, 2.5dg longitude ~ 155km
106
107	// the ultra fast method (and only slightly inaccurate as long as we only cover a limited geographically area)
108	// is using an aproximation of the length of 1 latitude degree and 1 longitude degree and just use pythagoras to
109	// calculate the distance:
110	// sqrt( power(abs(latitude-?)111320, 2) + power(abs(longitude-?)63000,2) )::int as calcdist
111
112	public List<StationBean> getByLocation(double latitude, double longitude) throws SQLException {
113	String SQL = "SELECT id,name,latitude,longitude,stationcode_fjrn,stationcode_stog, stationcode_metro, address," +
114	" earth_distance( earth_coord, ll_to_earth(?,?))::int AS calcdist " +
115	"FROM trainstations " +
116	"WHERE enabled = true AND abs(latitude-?)<1.5 AND abs(longitude-?)<2.5 " +
117	"ORDER BY calcdist ASC " +
118	"LIMIT 4 ";
119	List<StationBean> result;
120	Connection conn = null;
121	PreparedStatement stmt = null;
122	ResultSet res = null;
123	try {
124	conn = DBConnection.getConnection();
125	stmt = conn.prepareStatement(SQL);
126	stmt.setDouble(1, latitude);
127	stmt.setDouble(2, longitude);
128	stmt.setDouble(3, latitude);
129	stmt.setDouble(4, longitude);
130	res = stmt.executeQuery();
131	result = convertResultset(res);
132
133	} finally {
134	if (res != null)
135	res.close();
136	if (stmt != null)
137	stmt.close();
138	if (conn!= null)
139	conn.close();
140	}
141	return result;
142	}
143
144	public List<StationBean> getByList(String list) throws SQLException {
145	String SQL = "SELECT id,name,latitude,longitude,stationcode_fjrn,stationcode_stog,stationcode_metro, address,0.0 " +
146	"FROM trainstations " +
147	"WHERE id IN " + list + " AND enabled = true " +
148	"ORDER BY name ";
149
150	Connection conn = null;
151	Statement stmt = null;
152	ResultSet res = null;
153	List<StationBean> result;
154
155	try {
156	conn = DBConnection.getConnection();
157	stmt = conn.createStatement();
158	res = stmt.executeQuery(SQL);
159	result = convertResultset(res);
160	} finally {
161	if (res != null)
162	res.close();
163	if (stmt != null)
164	stmt.close();
165	if (conn!= null)
166	conn.close();
167	}
168
169	return result;
170
171	}
172	public static String getStationName(int stationID) {
173	String station = "";
174
175	Connection conn = null;
176	try {
177	conn = DBConnection.getConnection();
178	Statement stmt = conn.createStatement();
179	ResultSet rs = stmt.executeQuery("SELECT name FROM trainstations WHERE id=" + stationID);
180	if (rs.next()) {
181	station = rs.getString(1);
182	}
183
184	} catch (Exception e) {
185	} finally {
186	try {
187	if (conn != null && !conn.isClosed())
188	conn.close();
189	} catch (Exception e) {}
190	}
191
192	return station;
193	}
194	}