rx.util.async.operators.OperatorStartFuture Maven / Gradle / Ivy
/**
* Copyright 2014 Netflix, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package rx.util.async.operators;
import java.util.concurrent.Future;
import rx.Observable;
import rx.Scheduler;
import rx.functions.Func0;
/**
* Start an asynchronous Future immediately and observe its result through
* an observable.
*/
public final class OperatorStartFuture {
/** Utility class. */
private OperatorStartFuture() { throw new IllegalStateException("No instances!"); }
/**
* Invokes the asynchronous function, surfacing the result through an observable sequence.
*
* Important note subscribing to the resulting observable blocks until
* the future completes.
* @param the result type
* @param functionAsync the asynchronous function to run
* @return the observable
*/
public static Observable startFuture(Func0> functionAsync) {
Future task;
try {
task = functionAsync.call();
} catch (Throwable t) {
return Observable.error(t);
}
return Observable.from(task);
}
/**
* Invokes the asynchronous function, surfacing the result through an observable sequence
* running on the given scheduler.
* @param the result type
* @param functionAsync the asynchronous function to run
* @param scheduler the scheduler where the completion of the Future is awaited
* @return the observable
*/
public static Observable startFuture(Func0> functionAsync,
Scheduler scheduler) {
Future task;
try {
task = functionAsync.call();
} catch (Throwable t) {
return Observable.error(t);
}
return Observable.from(task, scheduler);
}
}