Try this
PersistenceManager pm = PMF.get().getPersistenceManager();
Key key = KeyFactory.createKey(Marker.class.getSimpleName(),
marker_id);
Query query = persistenceManager.newQuery(Marker.class);
query.setFilter("marker_id == keyParam");
query.declareImports("import
com.google.appengine.api.datastore.Key;");
query.declareParameters("Key keyParam");
try{
query.deletePersistentAll(key);
} finally {
query.closeAll();
persistenceManager.close();
}
On Aug 3, 12:20 pm, sanja <[email protected]> wrote:
> What error do you get?
>
> On Aug 1, 11:06 am, Sap_junior <[email protected]> wrote:
>
> > Hello !
>
> > I have a problem with retriving objects by Key. I searched this error
> > in google , but didn't find any useful information about it.
>
> > Here is the code:
>
> > @PersistenceCapable
> > public class Marker {
> > @PrimaryKey
> > @Persistent(valueStrategy = IdGeneratorStrategy.IDENTITY)
> > private Key marker_id;
> > @Persistent
> > private String marker_name;
> > @Persistent
> > private Double marker_lat;
> > @Persistent
> > private Double marker_lng;
> > @Persistent
> > private String marker_address;
> > @Persistent
> > private String marker_content;
> > .....
>
> > }
>
> > Here is the code of the servlet ( which must retrive an object and
> > delete)
>
> > .......
> > String marker_id_str = req.getParameter("marker_id").trim();
> > Long marker_id = null;
>
> > try{
> > marker_id = Long.parseLong(marker_id_str.trim());
> > }
>
> > catch(Exception e){
> > e.getStackTrace();
> > }
> > .....
> > Key k = null;
> > PersistenceManager pm = null;
> > try{
> > k = KeyFactory.createKey(Marker.class.getSimpleName(),
> > marker_id);
> > //Long k =
> > Long.parseLong(req.getParameter("marker_id").trim());
> > pm = PMF.get().getPersistenceManager();
> > Marker marker = pm.getObjectById(Marker.class, k);
> > out.println(marker.getMarker_id() +
> > marker.getMarker_name());
> > //pm.deletePersistent(marker);
> > }
> > catch(Exception e){
> > e.printStackTrace();
> > }
> > finally{
> > pm.close();
> > }
> > ........
>
> > I get this error :
>
>
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