FluxToMessageChannelResultAdapter.java

/*
 * Copyright 2016 the original author or authors.
 *
 * 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 org.springframework.cloud.stream.reactive;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import reactor.core.publisher.Flux;

import org.springframework.cloud.stream.binding.StreamListenerResultAdapter;
import org.springframework.integration.support.MessageBuilder;
import org.springframework.messaging.Message;
import org.springframework.messaging.MessageChannel;

/**
 * A {@link org.springframework.cloud.stream.binding.StreamListenerResultAdapter} from a {@link Flux}
 * return type to a bound {@link MessageChannel}.
 * @author Marius Bogoevici
 */
public class FluxToMessageChannelResultAdapter
		implements StreamListenerResultAdapter<Flux<?>, MessageChannel> {

	private Log log = LogFactory.getLog(FluxToMessageChannelResultAdapter.class);

	@Override
	public boolean supports(Class<?> resultType, Class<?> bindingTarget) {
		return Flux.class.isAssignableFrom(resultType) && MessageChannel.class.isAssignableFrom(bindingTarget);
	}

	public void adapt(Flux<?> streamListenerResult, MessageChannel bindingTarget) {
		streamListenerResult
				.doOnError(e -> this.log.error("Error while processing result", e))
				.retry()
				.subscribe(
						result -> bindingTarget.send(result instanceof Message<?> ? (Message<?>) result
								: MessageBuilder.withPayload(result).build()));
	}
}