Does the server console log say anything?
On Sun, Mar 21, 2010 at 8:13 PM, alosii <[email protected]> wrote:
> So I've been struggling with a very simple thing. I have a User that
> contains a list of items. I want to remove an item from this list. I
> do this by doing this:
>
> 1.- Get the user from the db
> 2.- Remove the item from the list
> 3.- Call an update on the user
>
> On code:
>
> public void removePlaylist(String userID, String playlistName) {
> XYZUserContainer userCont = new XYZUserContainer();
> XYZUser user = userCont.getUserByEmail(userID);
> user.removePlaylist(playlistName);
> userCont.updateUser(user);
> }
>
> The problem: the change is not saved on the DB. The user's list is
> correctly modified but is not persisted.
>
> "How do you update it?" you must me asking:
> public XYZUser updateUser(XYZUser user) {
> PersistenceManager pm = PMF.get().getPersistenceManager();
> Transaction tx = pm.currentTransaction();
> try {
> tx.begin();
> XYZUser updatedUser = pm.makePersistent(user);
> tx.commit();
> return updatedUser;
> } catch (RuntimeException ex) {
> ex.printStackTrace();
> throw ex;
> } finally {
> if (tx.isActive()) {
> tx.rollback();
> }
> pm.close();
> }
> }
>
> "How do you get the user?"
> public XYZUser getUserByEmail(String email) {
> PersistenceManager pm = PMF.get().getPersistenceManager();
> pm.setDetachAllOnCommit(true);
> try {
> XYZUser user = pm.getObjectById(XYZUser.class,
> email);
> pm.close();
> return user;
> } catch (javax.jdo.JDOObjectNotFoundException e) {
> pm.close();
> return null;
> }
> }
>
>
>
> The annotations:
>
> ==================================================================================
> XYZUser:
> public class XYZUser {
> ....
>
> @Persistent(defaultFetchGroup="true")
> @Expose
> private List<XYZMusicList> djLists = new ArrayList<XYZMusicList>();
>
>
> ==================================================================================
>
> XYZMusicList:
> @PersistenceCapable(identityType = IdentityType.APPLICATION,
> detachable="true")
> public class XYZMusicList {
> @PrimaryKey
> @Persistent(valueStrategy = IdGeneratorStrategy.IDENTITY)
> private Key id;
>
> @Persistent
> @Expose
> private String nameOfList;
>
> @Persistent(defaultFetchGroup="true")
> @Expose
> private List<Long> musicList = new ArrayList<Long>();
>
> @Override
> public boolean equals(Object obj) {
> try{
> XYZMusicList listaAntigua = (XYZMusicList) obj;
>
> if(this.nameOfList.compareToIgnoreCase(listaAntigua.nameOfList)==0)
> return true;
> }catch(ClassCastException e){
> return false;
> }
> return false;
> }
>
>
> ==================================================================================
>
> I've read the following page (http://www.datanucleus.org/products/
> accessplatform_1_1/jdo/orm/one_to_many_list.html<http://www.datanucleus.org/products/%0Aaccessplatform_1_1/jdo/orm/one_to_many_list.html>)
> but there are no
> examples with the annotations that google app engine uses.
>
> Any ideas on whats wrong?
>
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>
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