[infinispan-issues] [JBoss JIRA] Commented: (ISPN-881) A listener which receives CacheEntryCreatedEvent + CacheEntryModifiedEvent events always has a null value after a Cache.put while a Cache.put which replaces delivers the actual value.

[Manik Surtani (JIRA)]

    [ https://issues.jboss.org/browse/ISPN-881?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12576462#comment-12576462 ] 

Manik Surtani commented on ISPN-881:
------------------------------------

Re: reading from the cache, this will be null since the entry hasn't been stored yet (since the transaction only completes after the listener is fired).

Regarding the null, I'm not sure what you are suggesting here?  CREATE events just indicate that an entry has been created; _not_ that a value has been set.  Are you suggesting combining CREATE and MODIFIED events to a single event?  This would break a lot of existing applications and cannot be changed at this time.

> A listener which receives CacheEntryCreatedEvent + CacheEntryModifiedEvent events always has a null value after a Cache.put while a Cache.put which replaces delivers the actual value.
> ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
>
>                 Key: ISPN-881
>                 URL: https://issues.jboss.org/browse/ISPN-881
>             Project: Infinispan
>          Issue Type: Bug
>          Components: Listeners
>    Affects Versions: 4.2.0.CR3
>         Environment: N/A
>            Reporter: Miroslav Pokorny
>            Assignee: Manik Surtani
>
> It would be advantageous if the beheaviour of the delivered modify events did not deliver null values after a put which is different from a put which replaces which does deliver the actual value. It is also not possible to take the key from the create event and try and read the cache. I have tried printing both when the Event.isPre() field is false and true and the value is null.
> Please examine the provided test harness which includes some prints the output which demonstrates the problem...
> ---
> package miroslav.pokorny.cache.infinispan;
> import org.infinispan.manager.DefaultCacheManager;
> import org.infinispan.manager.EmbeddedCacheManager;
> import org.infinispan.notifications.Listener;
> import org.infinispan.notifications.cachelistener.annotation.CacheEntryCreated;
> import org.infinispan.notifications.cachelistener.annotation.CacheEntryModified;
> import org.infinispan.notifications.cachelistener.event.CacheEntryCreatedEvent;
> import org.infinispan.notifications.cachelistener.event.CacheEntryModifiedEvent;
> public class InfinispanValueProblemTest {
>     private final static String KEY = "key";
>     private final static String VALUE = "*Value*";
>     static public void main(final String[] ignored) {
>         final EmbeddedCacheManager manager = new DefaultCacheManager();
>         final org.infinispan.Cache<String, String> cache = manager.getCache();
>         cache.addListener(new InfinispanCacheListener());
>         cache.put(KEY, VALUE);
>     }
>     @Listener
>     static final public class InfinispanCacheListener {
>         @CacheEntryCreated
>         public void entryCreated(final CacheEntryCreatedEvent<String, String> event) {
>             System.out.println("CREATE EVENT\n\t" + event.getKey() + "= cant do get value\n\tisPre=" + event.isPre()
>                     + "\n\tevent.getCache().get(event.getKey())=" + event.getCache().get(event.getKey()));
>         }
>         @CacheEntryModified
>         public void entryModified(final CacheEntryModifiedEvent<String, String> event) {
>             System.out.println("MODIFIED EVENT\n\t" + event.getKey() + "=" + event.getValue() + "\n\tisPre=" + event.isPre()
>                     + "\n\tevent.getCache().get(event.getKey())=" + event.getCache().get(event.getKey()));
>         }
>     }
> }
> -------------------------------------------
> Running the test should print something like this
> [       GlobalComponentRegistry] - Infinispan version: Infinispan 'Ursus' 4.2.0.CR3
> [             ComponentRegistry] - Infinispan version: Infinispan 'Ursus' 4.2.0.CR3
> CREATE EVENT
> 	key= cant do get value
> 	isPre=true
> 	event.getCache().get(event.getKey())=null
> CREATE EVENT
> 	key= cant do get value
> 	isPre=false
> 	event.getCache().get(event.getKey())=null
> MODIFIED EVENT
> 	key=null
> 	isPre=true
> 	event.getCache().get(event.getKey())=null
> MODIFIED EVENT
> 	key=*Value*
> 	isPre=false
> 	event.getCache().get(event.getKey())=null

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