[appengine-java] Re: Geomodel in Java
Now, I am trying to use the proximity search in Geomodel. However, I
am facing a problem, which I am not sure what it is, but I think it is
related to either my PersistentManager or baseQuery. I ran the query,
however, while my database is not empty, I got null results.
public class HowToUseGeocell extends TestCase {
...
public int ProximitySearch(double lat, double lon, double distance) {
Point center = new Point(lat, lon);
ListObjectToSave objects = null;
PersistenceManager pm = PMF.get().getPersistenceManager();
try{
ListObject params = new ArrayListObject();
params.add(Mahsa);
GeocellQuery baseQuery = new GeocellQuery(Owner ==
OwnerParam, String OwnerParam, params);
try {
objects = GeocellManager.proximityFetch(center, 40,
distance, ObjectToSave.class, baseQuery, pm);
Assert.assertTrue(objects.size() 0);
} catch (Exception e) {
// We catch excption here because we have not
configured the PersistentManager (and so the queries won't work)
}
} finally {
pm.close();
}
if (objects == null)
return -3;
else
return objects.size();
}
}
Here is my ObjectToSave class:
@PersistenceCapable(detachable=true)
public class ObjectToSave implements LocationCapable {
@PrimaryKey
@Persistent
private long id;
@Persistent
private double latitude;
@Persistent
private double longitude;
@Persistent
private double altitude;
@Persistent
private ListString geocells;
@Persistent
private String owner;
public long getId() {
return id;
}
public void setId(long id) {
this.id = id;
}
public double getLatitude() {
return latitude;
}
public void setLatitude(double latitude) {
this.latitude = latitude;
}
public double getLongitude() {
return longitude;
}
public void setLongitude(double longitude) {
this.longitude = longitude;
}
public double getAltitude() {
return altitude;
}
public void setAltitude(double alt) {
this.altitude = alt;
}
public ListString getGeocells() {
return geocells;
}
public void setGeocells(ListString geocells) {
this.geocells = geocells;
}
public String getKeyString() {
return Long.valueOf(id).toString();
}
public Point getLocation() {
return new Point(latitude, longitude);
}
public String getOwner() {
return owner;
}
public void setOwner(String o) {
this.owner = o;
}
}
My PMF class:
public final class PMF {
private static final PersistenceManagerFactory pmfInstance =
JDOHelper.getPersistenceManagerFactory(transactions-
optional);
private PMF() {}
public static PersistenceManagerFactory get() {
return pmfInstance;
}
}
My Servlet:
@SuppressWarnings(serial)
public class Test8_Geomodel_GAEServlet extends HttpServlet {
// public static UseGeocell GC = new UseGeocell();
//public final static PersistenceManagerFactory pmfInstance =
JDOHelper.getPersistenceManagerFactory(transactions-optional);
public void doGet(HttpServletRequest req, HttpServletResponse resp)
throws IOException {
doPost(req, resp);
// resp.setContentType(text/plain);
// resp.getWriter().println(Hello, world);
}
public void doPost(HttpServletRequest req, HttpServletResponse resp)
throws IOException {
HowToUseGeocell gc = new HowToUseGeocell();
ListObjectToSave obj = new ArrayListObjectToSave();
//Read Excel source file (which is defined in web.xml file)
store it in datastore
ServletContext context = getServletContext();
String file_path = context.getRealPath(LiDAR.xls);
File Myfile = new File(file_path);
Workbook workBook;
int PointNo;
double latitude = 0.0, longitude = 0.0, altitude = 0.0;
String owner = ;
try {
workBook = Workbook.getWorkbook(Myfile);
Sheet sheet = workBook.getSheet(0);
int NumOfColumns = sheet.getColumns();
int NumOfRows = sheet.getRows();
String data;
for(int row = 1; row NumOfRows; row++) {
for(int col = 0; col NumOfColumns; col++) {
data = sheet.getCell(col, row).getContents();
data = sheet.getCell(0,
row).getContents();
PointNo =
Integer.parseInt(data.toString
[appengine-java] Geomodel Java: Proximity Search
I am trying to use the proximity search of Geomodel. However, I
am facing a problem, which I am not sure what it is, but I think it is
related to either my PersistentManager or baseQuery. I ran the query,
however, while my database is not empty, I got null results.
Here are my codes:
public class HowToUseGeocell extends TestCase {
...
public int ProximitySearch(double lat, double lon, double distance) {
Point center = new Point(lat, lon);
ListObjectToSave objects = null;
PersistenceManager pm = PMF.get().getPersistenceManager();
try{
ListObject params = new ArrayListObject();
params.add(Mahsa);
GeocellQuery baseQuery = new GeocellQuery(Owner ==
OwnerParam, String OwnerParam, params);
try {
objects = GeocellManager.proximityFetch(center, 40,
distance, ObjectToSave.class, baseQuery, pm);
Assert.assertTrue(objects.size() 0);
} catch (Exception e) {
// We catch excption here because we have not
configured the PersistentManager (and so the queries won't work)
}
} finally {
pm.close();
}
if (objects == null)
return -3;
else
return objects.size();
}
}
Here is my ObjectToSave class:
@PersistenceCapable(detachable=true)
public class ObjectToSave implements LocationCapable {
@PrimaryKey
@Persistent
private long id;
@Persistent
private double latitude;
@Persistent
private double longitude;
@Persistent
private double altitude;
@Persistent
private ListString geocells;
@Persistent
private String owner;
public long getId() {
return id;
}
public void setId(long id) {
this.id = id;
}
public double getLatitude() {
return latitude;
}
public void setLatitude(double latitude) {
this.latitude = latitude;
}
public double getLongitude() {
return longitude;
}
public void setLongitude(double longitude) {
this.longitude = longitude;
}
public double getAltitude() {
return altitude;
}
public void setAltitude(double alt) {
this.altitude = alt;
}
public ListString getGeocells() {
return geocells;
}
public void setGeocells(ListString geocells) {
this.geocells = geocells;
}
public String getKeyString() {
return Long.valueOf(id).toString();
}
public Point getLocation() {
return new Point(latitude, longitude);
}
public String getOwner() {
return owner;
}
public void setOwner(String o) {
this.owner = o;
}
}
My PMF class:
public final class PMF {
private static final PersistenceManagerFactory pmfInstance =
JDOHelper.getPersistenceManagerFactory(transactions-
optional);
private PMF() {}
public static PersistenceManagerFactory get() {
return pmfInstance;
}
}
My Servlet:
@SuppressWarnings(serial)
public class Test8_Geomodel_GAEServlet extends HttpServlet {
// public static UseGeocell GC = new UseGeocell();
//public final static PersistenceManagerFactory pmfInstance =
JDOHelper.getPersistenceManagerFactory(transactions-optional);
public void doGet(HttpServletRequest req, HttpServletResponse
resp)
throws IOException {
doPost(req, resp);
// resp.setContentType(text/plain);
// resp.getWriter().println(Hello, world);
}
public void doPost(HttpServletRequest req, HttpServletResponse
resp)
throws IOException {
HowToUseGeocell gc = new HowToUseGeocell();
ListObjectToSave obj = new
ArrayListObjectToSave();
//Read Excel source file (which is defined in
web.xml file)
store it in datastore
ServletContext context = getServletContext();
String file_path = context.getRealPath(LiDAR.xls);
File Myfile = new File(file_path);
Workbook workBook;
int PointNo;
double latitude = 0.0, longitude = 0.0, altitude =
0.0;
String owner = ;
try {
workBook = Workbook.getWorkbook(Myfile);
Sheet sheet = workBook.getSheet(0);
int NumOfColumns = sheet.getColumns();
int NumOfRows = sheet.getRows();
String data;
for(int row = 1; row NumOfRows; row++) {
for(int col = 0; col NumOfColumns; col++) {
data = sheet.getCell(col,
row).getContents();
data = sheet.getCell(0,
row).getContents();
PointNo =
Integer.parseInt(data.toString
[appengine-java] Re: Geomodel in Java
Hi Stephen,
Thanks for your help. The problem has been solved by adding the
libraries into the class path.
On Jul 16, 7:33 pm, Stephen Johnson onepagewo...@gmail.com wrote:
Hi Mahsa,
You have these imports:
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;
So, one obvious question since you are getting NoClassDefFoundError:
com/beoui/geocell/model/Point is: Did you put the appropriate JAR file
in WEB-INF/lib or if these classes are not in a JAR, did you put them
in WEB-INF/classes directory?
Stephen Johnson
On Jul 13, 1:13 pm, Mahsa mahsa.ghafour...@gmail.com wrote:
Hello,
I am developing a simple GIS cloud application using Google App Engine
Geomodel. In this application, I would like to store latitude and
longitude of points from user, later on query them using boundingbox
proximity queries. I am experiencing problem while trying to access
the server through a browser. I appreciate it if someone help me with
this regard.
I am usingEclipse, 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
inhttp://code.google.com/p/javageomodel/source/browse/trunk/geocell/src...
ObjectToSave is
exactlyhttp://code.google.com/p/javageomodel/source/browse/trunk/geocell/src...
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.gellib...@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
ListString 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
[appengine-java] Geomodel in Java
Hello,
I am developing a simple GIS cloud application using Google App Engine
Geomodel. In this application, I would like to store latitude and
longitude of points from user, later on query them using boundingbox
proximity queries. I am experiencing problem while trying to access
the server through a browser. I appreciate it if someone help me with
this regard.
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.gellib...@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
ListString 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)
ListString cells = GeocellManager.bestBboxSearchCells(bb,
null);
// OR if you want to use a custom cost function
ListString 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
