Using the Infinispan Client - remove() does not return value from cache

[schall1337]

Hello,
I am trying out the infinispan client from https://github.com/quarkusio/quarkus-quickstarts.git -> infinispan-client-quickstart

I added an additional endpoint 'deleteGreeting' to delete entries from cache in the class InfinispanGreetingResource
`@Path("/greeting")
public class InfinispanGreetingResource {

@Inject
@Remote("mycache")
RemoteCache<String, Greeting> cache;

@POST
@Path("/{id}")
public CompletionStage<String> postGreeting(String id, Greeting greeting) {
    return cache.putAsync(id, greeting)
          .thenApply(g -> "Greeting added!")
          .exceptionally(ex -> ex.getMessage());
}

@GET
@Path("/{id}")
public CompletionStage<Greeting> getGreeting(String id) {
    return cache.getAsync(id);
}

@DELETE
@Path("/{id}")
public String deleteGreeting(String id) {
    Greeting removed = cache.remove(id);
    if(removed != null){
        return "DELETED Successfully!";
    }
    return "No object found to be deleted!";
}

}`

When call the method postGreeting I can see that an entry was successfully added to the cache with the message 'Greeting added!' and in the infinispan console (GUI).

Now when I call the endpoint deleteGreeting cache.remove(id); returns null and I see the message "No object found to be deleted!";
Though in the infinispan console (GUI) the entry was removed from the cache.

The doc states https://docs.jboss.org/infinispan/15.0/apidocs/org/infinispan/commons/api/BasicCache.html#remove(java.lang.Object)
Specified by:
remove in interface Map<K,V>
Returns:
the previous value associated with key, or null if there was no mapping for key

What am I doing wrong? Why is cache.remove(id); returning null and not the removed value for given key?

[quarkus-bot[bot]]

/cc @gwenneg (cache), @karesti (infinispan), @wburns (infinispan)

[karesti]

@schall1337 try

cache.withFlags(Flag.FORCE_RETURN_VALUE).remove(id)

[karesti]

The explanation for this: bringing the removed value has a cost (in production env), so by default the value is not returned. however if you need the deleted value, you can use the flag, so the removed value is returned.

[schall1337]

makes sense, somehow I overlooked that options! Thanks very much for the answer and your work.