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9 years ago I am using Eclipse, and here is what I did:
1) Created a Web application project enabling only Google App Engine (1.3.4)(as
Google SDK)
2) Created a simple jsp file in "war" folder to get latitude & longitude from
user
3) Created two java classes, UseGeocell and ObjectToSave. UseGeocell class is
similar to the code in
http://code.google.com/p/javageomodel/source/browse/trunk/geocell/src/test/java/
com/beoui/utils/HowToUseGeocell.java
ObjectToSave is exactly
http://code.google.com/p/javageomodel/source/browse/trunk/geocell/src/test/java/
com/beoui/utils/ObjectToSave.java
4)In my Servlet I defined an object of type UseGeocell and called
testHowToSaveGeocellsInDatabase function in order to save latitude & longitude
that are obtained from the input
Here is my code:
My UseGeocell class:
package edu.pitt.Test8_Geomodel_GAE;
import java.util.ArrayList;
import java.util.List;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.jdo.PersistenceManager;
import junit.framework.Assert;
import junit.framework.TestCase;
import com.beoui.geocell.GeocellManager;
import com.beoui.geocell.model.BoundingBox;
import com.beoui.geocell.model.CostFunction;
import com.beoui.geocell.model.GeocellQuery;
import com.beoui.geocell.model.Point;
/**
* Unit test also used to explain how to use Geocell class.
*
* @author Alexandre Gellibert <alexandre.gellibert@gmail.com>
*
*/
public class UseGeocell extends TestCase {
private final Logger log = Logger.getLogger("com.beoui.utils");
public ObjectToSave obj;
/**
* First step is to save your entities.
* In database, you don't save only latitude and longitude of your point but also geocells around this point.
*/
public void testHowToSaveGeocellsInDatabase(double lat, double lon) {
// Incoming data: latitude and longitude (Bordeaux for instance)
//double lat = 44.838611;
//double lon = -0.578333;
// Transform it to a point
Point p = new Point(lat, lon);
// Generates the list of GeoCells
List<String> cells = GeocellManager.generateGeoCell(p);
// Save your instance
obj = new ObjectToSave();
obj.setLatitude(lat);
obj.setLongitude(lon);
obj.setGeocells(cells);
//objDao.save(obj);
// Just checking that cells are not empty
Assert.assertTrue(cells.size() > 0);
// Show in the log what cells are going to be saved
log.log(Level.INFO, "Geocells to be saved for Point("+lat+","+lon+") are: "+cells);
}
/**
* Second step, now entities are in database, we can query on them.
* Here is the example of a bounding box query.
*
*/
public void testHowToQueryOnABoundingBox(double latSW, double lonSW, double latNE, double lonNE) {
// Incoming data: latitude and longitude of south-west and north-east points (around Bordeaux for instance =) )
//double latSW = 44.8;
//double lonSW = -0.6;
// double latNE = 44.9;
// double lonNE = -0.7;
// Transform this to a bounding box
BoundingBox bb = new BoundingBox(latNE, lonNE, latSW, lonSW);
// Calculate the geocells list to be used in the queries (optimize list of cells that complete the given bounding box)
List<String> cells = GeocellManager.bestBboxSearchCells(bb, null);
// OR if you want to use a custom "cost function"
List<String> cells2 = GeocellManager.bestBboxSearchCells(bb, new CostFunction() {
@Override
public double defaultCostFunction(int numCells, int resolution) {
if(numCells > 100) {
return Double.MAX_VALUE;
} else {
return 0;
}
}
});
// Use this in a query
// In Google App Engine, you'll have something like below. In hibernate (or whatever else), it might be a little bit different.
// String queryString = "select from ObjectToSave where
geocellsParameter.contains(geocells)";
// Query query = pm.newQuery(query);
// query.declareParameters("String geocellsParameter");
// query.declareParameters("String geocellsP");
// List<ObjectToSave> objects = (List<ObjectToSave>)
query.execute(cells);
// Just checking that cells are not empty
Assert.assertTrue(cells.size() > 0);
Assert.assertTrue(cells2.size() > 0);
// Show in the log what cells shoud be used in the query
log.log(Level.INFO, "Geocells to use in query for PointSW("+latSW+","+lonSW+") ; PointNE("+latNE+","+lonNE+") are: "+cells);
}
/**
* To test proximity search, you have to give your base query and it will be enhanced with geocells restrictions.
*
*/
// TODO configure persistent manager to run a real test
public void testHowToQueryWithProximitySearch(double lat, double lon) {
Point center = new Point(lat, lon);
PersistenceManager pm = null;// here put your persistent manager
List<Object> params = new ArrayList<Object>();
params.add("John");
GeocellQuery baseQuery = new GeocellQuery("lastName == lastNameParam", "String lastNameParam", params);
List<ObjectToSave> objects = null;
try {
objects = GeocellManager.proximityFetch(center, 40, 0, ObjectToSave.class, baseQuery, pm);
Assert.assertTrue(objects.size() > 0);
} catch (Exception e) {
// We catch exception here because we have not configured the PersistentManager (and so the queries won't work)
}
}
}
My servlet:
package edu.pitt.Test8_Geomodel_GAE;
import java.io.IOException;
import javax.servlet.http.*;
@SuppressWarnings("serial")
public class Test8_Geomodel_GAEServlet extends HttpServlet {
public void doGet(HttpServletRequest req, HttpServletResponse resp)
throws IOException {
doPost(req, resp);
}
public void doPost(HttpServletRequest req, HttpServletResponse resp)
throws IOException {
String lat = req.getParameter("txtlatitude");
String lon = req.getParameter("txtlongitude");
double latitude = Double.parseDouble(lat);
double longitude = Double.parseDouble(lon);
UseGeocell gc = new UseGeocell();
gc.testHowToSaveGeocellsInDatabase(latitude, longitude);
resp.sendRedirect("/main.jsp");
}
}
My jsp file:
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%@ page import="java.util.List" %>
<%@ page import="javax.jdo.PersistenceManager" %>
<%@ page import="com.google.appengine.api.users.User" %>
<%@ page import="com.google.appengine.api.users.UserService" %>
<%@ page import="com.google.appengine.api.users.UserServiceFactory" %>
<%@ page import="javax.jdo.PersistenceManager" %>
<%@ page import= "edu.pitt.Test8_Geomodel_GAE.Test8_Geomodel_GAEServlet" %>
<%@ page import= "edu.pitt.Test8_Geomodel_GAE.UseGeocell" %>
<html>
<head><title>Geomodel GAE Project_helloo2</title></head>
<body bgcolor="#ffffff" background="background.gif">
<table border="0" width="700">
<tr>
<td width="150"> </td>
<td width="50">
<h1>Enter a point:</h1>
</td>
</tr>
<tr>
<td width="150"> </td>
<td width="550">
<form action="/test8_geomodel_gae" method="post">
<br>Latitude:
<input type="text" name="txtlatitude" size="25">
<br>Longitude:
<input type="text" name="txtlongitude" size="25">
<br>
<input type="submit" value="Submit">
</form>
</td>
</tr>
</table>
</body>
</html>
My web.xml file:
<?xml version="1.0" encoding="utf-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns="http://java.sun.com/xml/ns/javaee"
xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" version="2.5">
<servlet>
<servlet-name>Test8_Geomodel_GAE</servlet-name>
<servlet-class>edu.pitt.Test8_Geomodel_GAE.Test8_Geomodel_GAEServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>Test8_Geomodel_GAE</servlet-name>
<url-pattern>/test8_geomodel_gae</url-pattern>
</servlet-mapping>
<welcome-file-list>
<welcome-file>main.jsp</welcome-file>
</welcome-file-list>
</web-app>
The code is compiled and run successfully. However, when in the browser, when I
submit latitude & longitude I receive an error as follow:
HTTP ERROR 500
Problem accessing /test8_geomodel_gae. Reason:
com/beoui/geocell/model/Point
Caused by:
java.lang.NoClassDefFoundError: com/beoui/geocell/model/Point
at edu.pitt.Test8_Geomodel_GAE.Test8_Geomodel_GAEServlet.doPost(Test8_Geomodel_GAEServlet.java:45)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:713)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:806)
at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:511)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1166)
at com.google.appengine.api.blobstore.dev.ServeBlobFilter.doFilter(ServeBlobFilter.java:51)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at com.google.apphosting.utils.servlet.TransactionCleanupFilter.doFilter(TransactionCleanupFilter.java:43)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at com.google.appengine.tools.development.StaticFileFilter.doFilter(StaticFileFilter.java:122)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:388)
at org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:216)
at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:182)
at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:765)
at org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:418)
at com.google.apphosting.utils.jetty.DevAppEngineWebAppContext.handle(DevAppEngineWebAppContext.java:70)
at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
at com.google.appengine.tools.development.JettyContainerService$ApiProxyHandler.handle(JettyContainerService.java:349)
at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
at org.mortbay.jetty.Server.handle(Server.java:326)
at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:542)
at org.mortbay.jetty.HttpConnection$RequestHandler.content(HttpConnection.java:938)
at org.mortbay.jetty.HttpParser.parseNext(HttpParser.java:755)
at org.mortbay.jetty.HttpParser.parseAvailable(HttpParser.java:218)
at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:404)
at org.mortbay.io.nio.SelectChannelEndPoint.run(SelectChannelEndPoint.java:409)
at org.mortbay.thread.QueuedThreadPool$PoolThread.run(QueuedThreadPool.java:582)
I am not sure what I am doing wrong. I really appreciate it if someone help me
with this issue.
Original comment by Mahsa.Gh...@gmail.com on 13 Jul 2010 at 8:08
- Added labels: ****
- Removed labels: ****
Original issue reported on code.google.com by
Mahsa.Gh...@gmail.comon 12 Jul 2010 at 5:07