Hello everyone.
I've an issue : I can't update a pojo object.
I have two classes : A user and a location.
A user HAS A location.
My servlet do this :
1) create a user without a location, make it persist
2) retrieve a user, set the location (for the first time), make it persist
3) retrieve a user, set a new location, make it persist
4) retrieve a user, show if the position has been updated
My issue :
On step 4), I see the location initialized the first time. My new position
is never saved.
More strange, I can see pojo location objects in the DataStore Viewer (
http://localhost:8888/_ah/admin/datastore)
If someone know how to fix it, I'll be grateful.
~Yoann~
Complete source code are in the attached files.
A more simple source :
Pojos:
@PersistenceCapable
public class POJOUser {
/** Primary key */
@PrimaryKey
@Persistent
private String key = null;
/** Username */
@Persistent
private String username = null;
/** Password */
@Persistent
private String password = null;
/** The last location of the user */
@Persistent
private POJOLocation lastLocation = null;
....
}
@PersistenceCapable
public class POJOLocation implements Location {
/** Primary key */
@PrimaryKey
@Persistent(valueStrategy = IdGeneratorStrategy.IDENTITY)
private Key key = null;
/** X */
@Persistent
private Double x = null;
/** Y */
@Persistent
private Double y = null;
....
}
PMF :
public class DataAccessLayerForGoogleAppEngine implements DataAccessLayer {
/** Persistence Manager */
private PersistenceManagerFactory PMF = JDOHelper
.getPersistenceManagerFactory("transactions-optional");
@Override
public void updateUserLocation(String username, Location newLocation) {
PersistenceManager pm = PMF.getPersistenceManager();
try {
// Get the user
POJOUser user = pm.getObjectById(POJOUser.class, username);
if (user != null) {
// Update the location
user.setLastLocation(new POJOLocation(newLocation));
}
} catch (JDOObjectNotFoundException ex) {
} finally {
pm.close();
}
}
...
}
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package lan.polichouz.tracer.server.impl;
import java.util.List;
import javax.jdo.JDOHelper;
import javax.jdo.JDOObjectNotFoundException;
import javax.jdo.PersistenceManager;
import javax.jdo.PersistenceManagerFactory;
import javax.jdo.Query;
import lan.polichouz.tracer.server.DataAccessLayer;
import lan.polichouz.tracer.server.Location;
import lan.polichouz.tracer.server.impl.pojo.POJOLocation;
import lan.polichouz.tracer.server.impl.pojo.POJOUser;
/**
* Implementation of a Data Access Layer using Google AppEngine framework.
*
* @author yoyo
*/
public class DataAccessLayerForGoogleAppEngine implements DataAccessLayer {
// TODO user and admin name MUST be unique (primary key).
/** Persistence Manager */
private PersistenceManagerFactory PMF = JDOHelper
.getPersistenceManagerFactory("transactions-optional");
@Override
public String getUsernamePassword(String username) {
String realPassword = null;
PersistenceManager pm = PMF.getPersistenceManager();
try {
// Get the user
POJOUser user = pm.getObjectById(POJOUser.class, username);
if (user != null) {
realPassword = user.getPassword();
}
} catch (JDOObjectNotFoundException ex) {
ex.printStackTrace();
} finally {
pm.close();
}
return realPassword;
}
@Override
public String getAdminPassword(String adminName) {
String realPassword = null;
PersistenceManager pm = PMF.getPersistenceManager();
try {
// Get the user
POJOUser user = pm.getObjectById(POJOUser.class, adminName);
if (user != null) {
// Get the password
realPassword = user.getPassword();
}
} catch (JDOObjectNotFoundException ex) {
} finally {
pm.close();
}
return realPassword;
}
@Override
public void updateUserLocation(String username, Location newLocation) {
PersistenceManager pm = PMF.getPersistenceManager();
try {
// Get the user
POJOUser user = pm.getObjectById(POJOUser.class, username);
if (user != null) {
// Update the location
user.setLastLocation(new POJOLocation(newLocation)); //XXX not saved
}
} catch (JDOObjectNotFoundException ex) {
} finally {
pm.close();
}
}
@Override
public Location getUserLocation(String username) {
Location location = null;
PersistenceManager pm = PMF.getPersistenceManager();
try {
// Get the user
POJOUser user = pm.getObjectById(POJOUser.class, username);
if (user != null) {
// Get the location
location = user.getLastLocation();
}
} catch (JDOObjectNotFoundException ex) {
} finally {
pm.close();
}
return location;
}
@SuppressWarnings("unchecked")
@Override
public void clear() {
List<POJOUser> users = null;
PersistenceManager pm = PMF.getPersistenceManager();
try {
Query query = pm.newQuery(POJOUser.class);
try {
// Get all users
System.out.println("Getting all users...");
users = (List<POJOUser>) query.execute();
System.out.println("Getting all users OK");
} finally {
query.closeAll();
}
// Remove all users
if (users != null) {
System.out.println("Deleting all users...");
pm.deletePersistentAll(users);
System.out.println("Deleting all users OK");
}
} finally {
pm.close();
}
}
@Override
public void initialize() {
PersistenceManager pm = PMF.getPersistenceManager();
try {
// Create an admin
POJOUser admin = new POJOUser("admin1", "pass");
pm.makePersistent(admin);
// Create a user
POJOUser user = new POJOUser("user1", "pass");
pm.makePersistent(user);
} finally {
pm.close();
}
}
}
package lan.polichouz.tracer.server.impl.pojo;
import javax.jdo.annotations.IdGeneratorStrategy;
import javax.jdo.annotations.PersistenceCapable;
import javax.jdo.annotations.Persistent;
import javax.jdo.annotations.PrimaryKey;
import com.google.appengine.api.datastore.Key;
import lan.polichouz.tracer.server.Location;
/**
* A simple X-Y location.
*
* @author yoyo
*/
@PersistenceCapable
public class POJOLocation implements Location {
/** Primary key */
@PrimaryKey
@Persistent(valueStrategy = IdGeneratorStrategy.IDENTITY)
private Key key = null;
/** X */
@Persistent
private Double x = null;
/** Y */
@Persistent
private Double y = null;
/**
* Initialize a new Pojo location.
*
* @param x
* @param y
*/
public POJOLocation(Double x, Double y) {
if (x == null) {
throw new IllegalArgumentException("x is invalid");
}
if (y == null) {
throw new IllegalArgumentException("y is invalid");
}
this.x = x;
this.y = y;
}
/**
* Initialize a new Pojo Location
* @param newLocation
*/
public POJOLocation(Location location) {
if (location == null) {
throw new IllegalArgumentException("location is invalid");
}
if (location.getX() == null) {
throw new IllegalArgumentException("location (X) is invalid");
}
if (location.getY() == null) {
throw new IllegalArgumentException("location (Y) is invalid");
}
x = location.getX();
y = location.getY();
}
/**
* Get the primary key.
* @return
*/
public Key getKey() {
return key;
}
@Override
public Double getX() {
return x;
}
@Override
public Double getY() {
return y;
}
@Override
public int hashCode() {
return toString().hashCode();
}
@Override
public boolean equals(Object obj) {
return obj instanceof POJOLocation
&& ((Location) obj).getX().equals(getX())
&& ((Location) obj).getY().equals(getY());
}
@Override
public String toString() {
StringBuilder builder = new StringBuilder();
builder.append("POJOLocation [x=");
builder.append(x);
builder.append(", y=");
builder.append(y);
builder.append("]");
return builder.toString();
}
}
package lan.polichouz.tracer.server.impl.pojo;
import javax.jdo.annotations.PersistenceCapable;
import javax.jdo.annotations.Persistent;
import javax.jdo.annotations.PrimaryKey;
import lan.polichouz.tracer.server.Location;
/**
* A user, with a username and a password.
*
* @author yoyo
*/
@PersistenceCapable
public class POJOUser {
/** Primary key */
@PrimaryKey
@Persistent
private String key = null;
/** Username */
@Persistent
private String username = null;
/** Password */
@Persistent
private String password = null;
/** The last location of the user */
@Persistent
private POJOLocation lastLocation = null;
/**
* Initialize a new user.
*
* @param username
* The user name
* @param password
* The user password.
*/
public POJOUser(String username, String password) {
// Check parameters
if (username == null || username.isEmpty()) {
throw new IllegalArgumentException("username is invalid");
}
if (password == null || password.isEmpty()) {
throw new IllegalArgumentException("password is invalid");
}
this.username = username;
this.password = password;
key = username;
}
/**
* Get the primary key.
*
* @return
*/
public String getKey() {
return key;
}
/**
* Get the user name.
*
* @return
*/
public String getUsername() {
return username;
}
/**
* Get the password.
*
* @return
*/
public String getPassword() {
return password;
}
/**
* Get the last location of the user.
*
* @return The last location of the user, or null if there are no location.
*/
public Location getLastLocation() {
return lastLocation;
}
/**
* Set the last location of the user.
*
* @param newLocation The new location of the user.
*/
public void setLastLocation(POJOLocation newLocation) {
lastLocation = newLocation;
}
@Override
public int hashCode() {
return toString().hashCode();
}
@Override
public boolean equals(Object obj) {
return obj instanceof POJOUser
&& ((POJOUser) obj).getUsername().equals(getUsername())
&& ((POJOUser) obj).getPassword().equals(getPassword());
}
@Override
public String toString() {
StringBuilder builder = new StringBuilder();
builder.append("User [username=");
builder.append(username);
builder.append(", password=");
builder.append(password);
builder.append("]");
return builder.toString();
}
}
