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package org.glassfish.jersey.examples.rx.agent;
import java.util.Collections;
import java.util.List;
import java.util.Queue;
import java.util.concurrent.ConcurrentLinkedQueue;
import javax.ws.rs.GET;
import javax.ws.rs.Path;
import javax.ws.rs.Produces;
import javax.ws.rs.client.WebTarget;
import javax.ws.rs.container.AsyncResponse;
import javax.ws.rs.container.Suspended;
import javax.ws.rs.core.GenericType;
import javax.inject.Singleton;
import org.glassfish.jersey.client.rx.rxjava2.RxFlowableInvoker;
import org.glassfish.jersey.client.rx.rxjava2.RxFlowableInvokerProvider;
import org.glassfish.jersey.examples.rx.domain.AgentResponse;
import org.glassfish.jersey.examples.rx.domain.Calculation;
import org.glassfish.jersey.examples.rx.domain.Destination;
import org.glassfish.jersey.examples.rx.domain.Forecast;
import org.glassfish.jersey.examples.rx.domain.Recommendation;
import org.glassfish.jersey.server.Uri;
import io.reactivex.Flowable;
import io.reactivex.schedulers.Schedulers;
/**
* Obtain information about visited (destination) and recommended (destination, forecast, price) places for "RxJava2"
* user. Uses RxJava2 Flowable and Jersey Client to obtain the data.
*
* @author Michal Gajdos
* @author Pavel Bucek (pavel.bucek at oracle.com)
*/
@Singleton
@Path("agent/flowable")
@Produces("application/json")
public class FlowableAgentResource {
@Uri("remote/destination")
private WebTarget destination;
@Uri("remote/calculation/from/{from}/to/{to}")
private WebTarget calculation;
@Uri("remote/forecast/{destination}")
private WebTarget forecast;
@GET
public void flowable(@Suspended final AsyncResponse async) {
final long time = System.nanoTime();
final Queue<String> errors = new ConcurrentLinkedQueue<>();
Flowable.just(new AgentResponse())
// Obtain visited destinations.
.zipWith(visited(errors), (agentResponse, visited) -> {
agentResponse.setVisited(visited);
return agentResponse;
})
// Obtain recommended destinations. (does not depend on visited ones)
.zipWith(
recommended(errors),
(agentResponse, recommendations) -> {
agentResponse.setRecommended(recommendations);
return agentResponse;
})
// Observe on another thread than the one processing visited or recommended destinations.
.observeOn(Schedulers.io())
// Subscribe.
.subscribe(agentResponse -> {
agentResponse.setProcessingTime((System.nanoTime() - time) / 1000000);
async.resume(agentResponse);
}, async::resume);
}
private Flowable<List<Destination>> visited(final Queue<String> errors) {
destination.register(RxFlowableInvokerProvider.class);
return destination.path("visited").request()
// Identify the user.
.header("Rx-User", "RxJava2")
// Reactive invoker.
.rx(RxFlowableInvoker.class)
// Return a list of destinations.
.get(new GenericType<List<Destination>>() {
})
// Handle Errors.
.onErrorReturn(throwable -> {
errors.offer("Visited: " + throwable.getMessage());
return Collections.emptyList();
});
}
private Flowable<List<Recommendation>> recommended(final Queue<String> errors) {
destination.register(RxFlowableInvokerProvider.class);
// Recommended places.
final Flowable<Destination> recommended = destination.path("recommended").request()
// Identify the user.
.header("Rx-User", "RxJava2")
// Reactive invoker.
.rx(RxFlowableInvoker.class)
// Return a list of destinations.
.get(new GenericType<List<Destination>>() {
})
// Handle Errors.
.onErrorReturn(throwable -> {
errors.offer("Recommended: " + throwable
.getMessage());
return Collections.emptyList();
})
// Emit destinations one-by-one.
.flatMap(Flowable::fromIterable)
// Remember emitted items for dependant requests.
.cache();
forecast.register(RxFlowableInvokerProvider.class);
// Forecasts. (depend on recommended destinations)
final Flowable<Forecast> forecasts = recommended.flatMap(destination ->
forecast
.resolveTemplate("destination", destination.getDestination())
.request().rx(RxFlowableInvoker.class).get(Forecast.class)
.onErrorReturn(throwable -> {
errors.offer("Forecast: " + throwable.getMessage());
return new Forecast(destination.getDestination(), "N/A");
}));
calculation.register(RxFlowableInvokerProvider.class);
// Calculations. (depend on recommended destinations)
final Flowable<Calculation> calculations = recommended.flatMap(destination -> {
return calculation.resolveTemplate("from", "Moon").resolveTemplate("to", destination.getDestination())
.request().rx(RxFlowableInvoker.class).get(Calculation.class)
.onErrorReturn(throwable -> {
errors.offer("Calculation: " + throwable.getMessage());
return new Calculation("Moon", destination.getDestination(), -1);
});
});
return Flowable.zip(recommended, forecasts, calculations, Recommendation::new).buffer(Integer.MAX_VALUE);
}
}