'Asynchronous processing with fallback java

I am working on an java application that will makes calls to a web service, I dont want to incur additional latency while making these calls hence I am planning on doing this asynchronously. Using threads is one way to go about it but this approach might become unreliable if the calls to the dependent service fail because of various reasons. So essentially what I am looking is some kind of in-process asynchronous service will fallback to temporarily store (inprocess database ?) and retry the failed requests. Are there are any exiting solutions out there that achieve this ? If not it would help if someone could point me to something that does a similar task like this.

Thanks

javadesign-patternsasynchronous


Solution 1:[1]

Actually, I've not yet tried it, but Reactor is something like Node.js and should allow you to program using event-driven paradigm.

Please check it out and let us know if it suits your needs.

Solution 2:[2]

Quarkus has easy built in reactive asynchronous call processing.

Like:


    @ApplicationScoped
    @RegisterForReflection
    @Path("/")
    public class JokesServiceCallManager {
    
        private static final Logger LOGGER = 
        LoggerFactory.getLogger(JokesServiceCallManager.class);
        
        @Inject
        JokeResponseHandler jokeResponseHandler;
    
        @Inject
        JokeSetupAdapter jokesSetupAdapter;
        
        @Inject
        JokeReactionAdapter jokesReactionAdapter;
        
        
        public Uni<Response> getData(String id,String correlationId) {
            
            LOGGER.debug("********** getData(String id) id = " + id);
             Uni<Response> uniSetup = jokesSetupAdapter.getByIdAsync(id);
             Uni<Response> uniReaction = 
             jokesReactionAdapter.getByIdAsync(id);
                 
            return Uni.combine().all().unis(uniSetup, uniReaction )
                        .asTuple().onItem().transformToUni(tuple -> 
                    jokeResponseHandler.createUniResponse(tuple.getItem1(), 
                    tuple.getItem2()));
                 //       .onFailure().invoke(exception -> 
              jokeResponseHandler.buildUniExceptionResponse(exception));
            }

Which returns a tuple of all the calls when complete. Simply allowing the service return to be cast to an Uni makes it all reactive (non-blocking)

The calls are as simple as :


    import javax.ws.rs.core.Response;
    
    import 
    org.eclipse.microprofile.rest.client.annotation.RegisterClientHeaders;
    import org.eclipse.microprofile.rest.client.inject.RegisterRestClient;
    
    import io.smallrye.mutiny.Uni;
    
    @RegisterRestClient(configKey="setup-api")
    @RegisterClientHeaders(SetupHeaderFactory.class)
    public interface JokesSetupService {
    
        @GET
        @Path("/jokesetup/{id}")
        @Produces(MediaType.APPLICATION_JSON)
        Uni<Response> getByIdAsync(@PathParam("id") String id);
    }

Sources

This article follows the attribution requirements of Stack Overflow and is licensed under CC BY-SA 3.0.

Source: Stack Overflow

Solution Source
Solution 1 Sergii Shevchyk
Solution 2 tbkahuna

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