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package org.glassfish.jersey.examples.rx.agent;
import java.util.Arrays;
import java.util.List;
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 org.glassfish.jersey.client.rx.RxWebTarget;
import org.glassfish.jersey.client.rx.guava.RxListenableFuture;
import org.glassfish.jersey.client.rx.guava.RxListenableFutureInvoker;
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.ManagedAsync;
import org.glassfish.jersey.server.Uri;
import com.google.common.base.Function;
import com.google.common.collect.Lists;
import com.google.common.util.concurrent.AsyncFunction;
import com.google.common.util.concurrent.FutureCallback;
import com.google.common.util.concurrent.Futures;
import com.google.common.util.concurrent.ListenableFuture;
import com.google.common.util.concurrent.SettableFuture;
/**
* Obtain information about visited (destination) and recommended (destination, forecast, price) places for "RxJava" user. Uses
* RxJava Observable and Jersey Client to obtain the data.
*
* @author Michal Gajdos (michal.gajdos at oracle.com)
*/
@Path("agent/listenable")
@Produces("application/json")
public class ListenableFutureAgentResource {
@Uri("remote/destination")
private WebTarget destination;
@Uri("remote/calculation/from/{from}/to/{to}")
private WebTarget calculation;
@Uri("remote/forecast/{destination}")
private WebTarget forecast;
@GET
@ManagedAsync
public void observable(@Suspended final AsyncResponse async) {
final long time = System.nanoTime();
final AgentResponse response = new AgentResponse();
// Fallback.
Futures.addCallback(Futures.successfulAsList(Arrays.asList(visited(response), recommended(response))),
new FutureCallback<List<AgentResponse>>() {
@Override
public void onSuccess(final List<AgentResponse> result) {
response.setProcessingTime((System.nanoTime() - time) / 1000000);
async.resume(response);
}
@Override
public void onFailure(final Throwable t) {
async.resume(t);
}
});
}
private ListenableFuture<AgentResponse> visited(final AgentResponse response) {
final ListenableFuture<List<Destination>> visited = RxListenableFuture.from(destination).path("visited").request()
// Identify the user.
.header("Rx-User", "Guava")
// Reactive invoker.
.rx()
// Return a list of destinations.
.get(new GenericType<List<Destination>>() {});
return Futures.transform(visited, new AsyncFunction<List<Destination>, AgentResponse>() {
@Override
public ListenableFuture<AgentResponse> apply(final List<Destination> input) throws Exception {
final SettableFuture<AgentResponse> future = SettableFuture.create();
response.setVisited(input);
future.set(response);
return future;
}
});
}
private ListenableFuture<AgentResponse> recommended(final AgentResponse response) {
// Destinations.
final ListenableFuture<List<Destination>> recommended = RxListenableFuture.from(destination).path("recommended").request()
// Identify the user.
.header("Rx-User", "Guava")
// Reactive invoker.
.rx()
// Return a list of destinations.
.get(new GenericType<List<Destination>>() {});
final ListenableFuture<List<Recommendation>> recommendations = Futures.transform(recommended,
new AsyncFunction<List<Destination>, List<Recommendation>>() {
@Override
public ListenableFuture<List<Recommendation>> apply(final List<Destination> input) throws Exception {
final List<Recommendation> recommendations = Lists.newArrayList(Lists.transform(input,
new Function<Destination, Recommendation>() {
@Override
public Recommendation apply(final Destination input) {
return new Recommendation(input.getDestination(), null, 0);
}
}));
return Futures.immediateFuture(recommendations);
}
});
final ListenableFuture<List<List<Recommendation>>> syncedFuture = Futures.successfulAsList(Arrays.asList(
// Add Forecasts to Recommendations.
forecasts(recommendations),
// Add Forecasts to Recommendations.
calculations(recommendations)));
return Futures.transform(syncedFuture, new AsyncFunction<List<List<Recommendation>>, AgentResponse>() {
@Override
public ListenableFuture<AgentResponse> apply(final List<List<Recommendation>> input) throws Exception {
response.setRecommended(input.get(0));
return Futures.immediateFuture(response);
}
});
}
private ListenableFuture<List<Recommendation>> forecasts(final ListenableFuture<List<Recommendation>> recommendations) {
return Futures.transform(recommendations,
new AsyncFunction<List<Recommendation>, List<Recommendation>>() {
@Override
public ListenableFuture<List<Recommendation>> apply(final List<Recommendation> input) throws Exception {
final RxWebTarget<RxListenableFutureInvoker> rxForecast = RxListenableFuture.from(forecast);
return Futures.successfulAsList(Lists.transform(input,
new Function<Recommendation, ListenableFuture<Recommendation>>() {
@Override
public ListenableFuture<Recommendation> apply(final Recommendation r) {
return Futures.transform(
rxForecast.resolveTemplate("destination", r.getDestination()).request().rx().get(Forecast.class),
new AsyncFunction<Forecast, Recommendation>() {
@Override
public ListenableFuture<Recommendation> apply(final Forecast f) throws Exception {
r.setForecast(f.getForecast());
return Futures.immediateFuture(r);
}
});
}
}));
}
});
}
private ListenableFuture<List<Recommendation>> calculations(final ListenableFuture<List<Recommendation>> recommendations) {
return Futures.transform(recommendations,
new AsyncFunction<List<Recommendation>, List<Recommendation>>() {
@Override
public ListenableFuture<List<Recommendation>> apply(final List<Recommendation> input) throws Exception {
final RxWebTarget<RxListenableFutureInvoker> rxCalculations = RxListenableFuture.from(calculation);
return Futures.successfulAsList(Lists.transform(input,
new Function<Recommendation, ListenableFuture<Recommendation>>() {
@Override
public ListenableFuture<Recommendation> apply(final Recommendation r) {
return Futures.transform(
rxCalculations.resolveTemplate("from", "Moon")
.resolveTemplate("to", r.getDestination()).request().rx().get(Calculation.class),
new AsyncFunction<Calculation, Recommendation>() {
@Override
public ListenableFuture<Recommendation> apply(final Calculation c) throws Exception {
r.setPrice(c.getPrice());
return Futures.immediateFuture(r);
}
});
}
}));
}
});
}
}