BasicReactorToCamelExample.java

/**
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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.apache.camel.example.reactive.streams;

import java.time.Duration;
import javax.annotation.PostConstruct;

import org.apache.camel.builder.RouteBuilder;
import org.apache.camel.component.reactive.streams.api.CamelReactiveStreamsService;
import org.reactivestreams.Subscriber;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
import org.springframework.context.annotation.Configuration;
import org.springframework.stereotype.Component;

import reactor.core.publisher.Flux;

/**
 * This example shows how a reactive stream framework can publish events that are consumed
 * by Camel routes.
 *
 * The exchange pattern is in-only from Reactor to Camel.
 *
 * Note: the Camel and reactor components are placed in the same configuration class for the sake of clarity,
 * but they can be moved in their own files.
 */
@Configuration
@ConditionalOnProperty("examples.basic.reactor-to-camel")
public class BasicReactorToCamelExample {

    /**
     * The reactor streams.
     */
    @Component
    public static class BasicReactorToCamelExampleStreams {

        @Autowired
        private CamelReactiveStreamsService camel;


        @PostConstruct
        public void setupStreams() {

            // Get a subscriber from camel
            Subscriber<String> elements = camel.streamSubscriber("elements", String.class);

            // Emit a string every 7 seconds and push it to the Camel "elements" stream
            Flux.interval(Duration.ofSeconds(7))
                    .map(item -> "element " + item)
                    .subscribe(elements);

        }
    }


    /**
     * The Camel Configuration.
     */
    @Component
    public static class BasicReactorToCamelExampleRoutes extends RouteBuilder {

        @Override
        public void configure() throws Exception {

            // Transform the body of received items and log
            from("reactive-streams:elements")
                    .setBody().simple("BasicReactorToCamel - Camel received ${body}")
                    .to("log:INFO");

        }

    }

}