thoerup/droidradarservice/LocationService.java

package dk.thoerup.droidradarservice;

import java.io.IOException;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;

import javax.naming.Context;
import javax.naming.InitialContext;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.sql.DataSource;

public class LocationService extends HttpServlet {
        private static final long serialVersionUID = 1L;


        public LocationService() {
                super();
                // TODO Auto-generated constructor stub
        }
        
        
        protected void updateDb(Connection conn, long imei, double latitude, double longitude, String handle, String group) throws SQLException {
                PreparedStatement stmt = null;
                try {
                        stmt = conn.prepareStatement("UPDATE droidradar SET handle=?, groupname=?, latitude=?, longitude=?, updated=now()  WHERE  imei=?");
                        stmt.setString(1, handle);
                        stmt.setString(2, group);
                        stmt.setDouble(3, latitude);
                        stmt.setDouble(4, longitude);
                        stmt.setLong(5, imei);
                        
                        int count = stmt.executeUpdate();
                        
                        
                        System.out.println("count" + count);
                        
                        if (count < 1) {
                                stmt.close();
                                stmt = conn.prepareStatement("INSERT INTO droidradar (imei,handle,groupname,latitude,longitude,updated) VALUES (?,?,?,?,?, now() )" );
                                stmt.setLong(1, imei);
                                stmt.setString(2, handle);
                                stmt.setString(3, group);
                                stmt.setDouble(4, latitude);
                                stmt.setDouble(5, longitude);
                                stmt.execute();
                        }
                } finally {
                        if (stmt != null && !stmt.isClosed())
                                stmt.close();
                }
        }
        
        protected String locateDroids(Connection conn, long imei, double latitude, double longitude) throws SQLException {
                //inner select is workaround from not being able to use a calculated column directly in where clause
                final String SQL = "SELECT * FROM ( "+
                                                   "               SELECT imei,handle,groupname,latitude,longitude, " +
                                                   "                     extract(epoch from now())::int - extract(epoch from updated)::int  AS lastupdate, " + 
                                                   "                     earth_distance( ll_to_earth(latitude,longitude), ll_to_earth(56,9))::int AS calcdist " + 
                                                   "               FROM droidradar " +
                           "               WHERE imei <> ? AND updated  > now() - interval '15 minutes'  " +
                                                   "       ) AS droidradar2 " +
                           "WHERE calcdist < 64000 " +
                                               "ORDER BY calcdist ASC ";
                
                System.out.println(SQL);
                
                PreparedStatement stmt = null;
                ResultSet res = null;
                
                StringBuffer buff = new StringBuffer();
                
                buff.append("<?xml version=\"1.0\"?>\n");
                buff.append("<droids>\n");
                try
                {
                        stmt = conn.prepareStatement(SQL);
                        stmt.setDouble(1, latitude);
                        stmt.setDouble(2, longitude);
                        stmt.setLong(3, imei);
                        
                        res = stmt.executeQuery();
                        
                        while (res.next()) {
                                buff.append("<droid>\n");
                                buff.append("<imei>").append(res.getLong(1) ) .append("</imei>\n");
                                buff.append("<handle>").append(res.getString(2) ) .append("</handle>\n");
                                buff.append("<group>").append(res.getString(3) ) .append("</group>\n");
                                buff.append("<latitude>").append(res.getString(4) ) .append("</latitude>\n");
                                buff.append("<longitude>").append(res.getString(5) ) .append("</longitude>\n");
                                buff.append("<lastupdate>").append(res.getInt(6) ) .append("</lastupdate>\n");                          
                                buff.append("<distance>").append(res.getDouble(7) ) .append("</distance>\n");
                                
                                buff.append("</droid>\n");                              
                        }
                } finally {
                        if (res != null && !res.isClosed())
                                res.close();
                        if (stmt != null && !stmt.isClosed())
                                stmt.close();
                }
                buff.append("</droids>\n");
                return buff.toString();
        }

        protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
                
                long imei = Long.parseLong(request.getParameter("imei"));
                
                double latitude = Double.parseDouble( request.getParameter("latitude"));
                double longitude = Double.parseDouble( request.getParameter("longitude"));
                
                
                String handle = request.getParameter("handle");
                String group = request.getParameter("group");
                
                
                Connection conn = null;
                try {
                        Context ctx = new InitialContext();
                        DataSource ds = (DataSource) ctx.lookup("java:comp/env/jdbc/test");
                        conn = ds.getConnection();
                        
                        updateDb(conn, imei, latitude, longitude, handle, group);
                        
                        String xml = locateDroids(conn, imei, latitude, longitude);
                        
                        response.setContentType("text/xml");
                        response.getWriter().print(xml);
                        
                        conn.close();
                        conn = null;
                        
                        
                } catch (Exception e) {
                        throw new ServletException(e);
                } finally {
                        try {
                                if (conn != null)
                                        conn.close();
                        } catch (Throwable t) {}
                }
                
        }

}
1	package dk.thoerup.droidradarservice;
2
3	import java.io.IOException;
4	import java.sql.Connection;
5	import java.sql.PreparedStatement;
6	import java.sql.ResultSet;
7	import java.sql.SQLException;
8
9	import javax.naming.Context;
10	import javax.naming.InitialContext;
11	import javax.servlet.ServletException;
12	import javax.servlet.http.HttpServlet;
13	import javax.servlet.http.HttpServletRequest;
14	import javax.servlet.http.HttpServletResponse;
15	import javax.sql.DataSource;
16
17	public class LocationService extends HttpServlet {
18	private static final long serialVersionUID = 1L;
19
20
21	public LocationService() {
22	super();
23	// TODO Auto-generated constructor stub
24	}
25
26
27	protected void updateDb(Connection conn, long imei, double latitude, double longitude, String handle, String group) throws SQLException {
28	PreparedStatement stmt = null;
29	try {
30	stmt = conn.prepareStatement("UPDATE droidradar SET handle=?, groupname=?, latitude=?, longitude=?, updated=now() WHERE imei=?");
31	stmt.setString(1, handle);
32	stmt.setString(2, group);
33	stmt.setDouble(3, latitude);
34	stmt.setDouble(4, longitude);
35	stmt.setLong(5, imei);
36
37	int count = stmt.executeUpdate();
38
39
40	System.out.println("count" + count);
41
42	if (count < 1) {
43	stmt.close();
44	stmt = conn.prepareStatement("INSERT INTO droidradar (imei,handle,groupname,latitude,longitude,updated) VALUES (?,?,?,?,?, now() )" );
45	stmt.setLong(1, imei);
46	stmt.setString(2, handle);
47	stmt.setString(3, group);
48	stmt.setDouble(4, latitude);
49	stmt.setDouble(5, longitude);
50	stmt.execute();
51	}
52	} finally {
53	if (stmt != null && !stmt.isClosed())
54	stmt.close();
55	}
56	}
57
58	protected String locateDroids(Connection conn, long imei, double latitude, double longitude) throws SQLException {
59	//inner select is workaround from not being able to use a calculated column directly in where clause
60	final String SQL = "SELECT * FROM ( "+
61	" SELECT imei,handle,groupname,latitude,longitude, " +
62	" extract(epoch from now())::int - extract(epoch from updated)::int AS lastupdate, " +
63	" earth_distance( ll_to_earth(latitude,longitude), ll_to_earth(56,9))::int AS calcdist " +
64	" FROM droidradar " +
65	" WHERE imei <> ? AND updated > now() - interval '15 minutes' " +
66	" ) AS droidradar2 " +
67	"WHERE calcdist < 64000 " +
68	"ORDER BY calcdist ASC ";
69
70	System.out.println(SQL);
71
72	PreparedStatement stmt = null;
73	ResultSet res = null;
74
75	StringBuffer buff = new StringBuffer();
76
77	buff.append("<?xml version=\"1.0\"?>\n");
78	buff.append("<droids>\n");
79	try
80	{
81	stmt = conn.prepareStatement(SQL);
82	stmt.setDouble(1, latitude);
83	stmt.setDouble(2, longitude);
84	stmt.setLong(3, imei);
85
86	res = stmt.executeQuery();
87
88	while (res.next()) {
89	buff.append("<droid>\n");
90	buff.append("<imei>").append(res.getLong(1) ) .append("</imei>\n");
91	buff.append("<handle>").append(res.getString(2) ) .append("</handle>\n");
92	buff.append("<group>").append(res.getString(3) ) .append("</group>\n");
93	buff.append("<latitude>").append(res.getString(4) ) .append("</latitude>\n");
94	buff.append("<longitude>").append(res.getString(5) ) .append("</longitude>\n");
95	buff.append("<lastupdate>").append(res.getInt(6) ) .append("</lastupdate>\n");
96	buff.append("<distance>").append(res.getDouble(7) ) .append("</distance>\n");
97
98	buff.append("</droid>\n");
99	}
100	} finally {
101	if (res != null && !res.isClosed())
102	res.close();
103	if (stmt != null && !stmt.isClosed())
104	stmt.close();
105	}
106	buff.append("</droids>\n");
107	return buff.toString();
108	}
109
110	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
111
112	long imei = Long.parseLong(request.getParameter("imei"));
113
114	double latitude = Double.parseDouble( request.getParameter("latitude"));
115	double longitude = Double.parseDouble( request.getParameter("longitude"));
116
117
118	String handle = request.getParameter("handle");
119	String group = request.getParameter("group");
120
121
122	Connection conn = null;
123	try {
124	Context ctx = new InitialContext();
125	DataSource ds = (DataSource) ctx.lookup("java:comp/env/jdbc/test");
126	conn = ds.getConnection();
127
128	updateDb(conn, imei, latitude, longitude, handle, group);
129
130	String xml = locateDroids(conn, imei, latitude, longitude);
131
132	response.setContentType("text/xml");
133	response.getWriter().print(xml);
134
135	conn.close();
136	conn = null;
137
138
139	} catch (Exception e) {
140	throw new ServletException(e);
141	} finally {
142	try {
143	if (conn != null)
144	conn.close();
145	} catch (Throwable t) {}
146	}
147
148	}
149
150	}