hu.akarnokd.rxjava2.interop.FlowInterop Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of rxjava2-jdk9-interop Show documentation
rxjava2-jdk9-interop developed by David Karnok
The newest version!
/*
 * Copyright 2016-2018 David Karnok
 *
 * 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 hu.akarnokd.rxjava2.interop;

import io.reactivex.Flowable;
import io.reactivex.functions.Function;
import io.reactivex.internal.functions.ObjectHelper;
import io.reactivex.plugins.RxJavaPlugins;
import io.reactivex.processors.FlowableProcessor;

import java.util.concurrent.Flow;

/**
 * Converters to and from Java 9 Flow components.
 * @since 0.1.0
 */
public final class FlowInterop {

    /** Utility class. */
    private FlowInterop() {
        throw new IllegalStateException("No instances!");
    }

    /**
     * Wraps a Flow.Publisher into a Flowable.
     * @param source the source Flow.Publisher, not null
     * @param  the value type
     * @return the new Flowable instance
     * @throws NullPointerException if source is null
     */
    @SuppressWarnings("unchecked")
    public static  Flowable fromFlowPublisher(Flow.Publisher source) {
        if (source instanceof Flowable) {
            return (Flowable)source;
        }
        if (source instanceof org.reactivestreams.Publisher) {
            return Flowable.fromPublisher((org.reactivestreams.Publisher)source);
        }
        ObjectHelper.requireNonNull(source, "source is null");
        return RxJavaPlugins.onAssembly(new FlowableFromFlowPublisher<>(source));
    }

    /**
     * Converter function from a Flowable into a Publisher.
     * @param  the value type
     * @return the Function instance to be used with {@code Flowable.to()}.
     */
    public static  Function, Flow.Publisher> toFlow() {
        return FlowFromPublisher::new;
    }

    /**
     * Wraps a Flow.Processor (identity) into a FlowableProcessor.
     * @param source the source Flow.Processor, not null
     * @param  the input and output type of the Flow.Processor
     * @return the new FlowableProcessor instance
     * @throws  NullPointerException if source is null
     */
    @SuppressWarnings("unchecked")
    public static  FlowableProcessor fromFlowProcessor(Flow.Processor source) {
        if (source instanceof FlowableProcessor) {
            return (FlowableProcessor)source;
        }
        ObjectHelper.requireNonNull(source, "source is null");
        return new FlowableProcessorFromFlowProcessor<>(source);
    }

    /**
     * Wraps an RS Publisher into a Flow.Publisher.
     * @param source the source RS Publisher instance, not null
     * @param  the value type
     * @return the new Flow.Publisher instance
     * @throws NullPointerException if source is null
     */
    @SuppressWarnings("unchecked")
    public static  Flow.Publisher toFlowPublisher(org.reactivestreams.Publisher source) {
        if (source instanceof Flow.Publisher) {
            return (Flow.Publisher)source;
        }
        ObjectHelper.requireNonNull(source, "source is null");
        return new FlowFromPublisher<>(source);
    }

    /**
     * Wraps an RS Processor into a Flow.Processor.
     * @param source the source RS Processor
     * @param  the input value type
     * @param  the output value type
     * @return the new Flow.Processor instance
     * @throws NullPointerException if source is null
     */
    @SuppressWarnings("unchecked")
    public static  Flow.Processor toFlowProcessor(org.reactivestreams.Processor source) {
        if (source instanceof Flow.Processor) {
            return (Flow.Processor)source;
        }
        ObjectHelper.requireNonNull(source, "source is null");
        return new FlowProcessorFromProcessor<>(source);
    }
}