BasicCamelToReactorInOutExample.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 org.apache.camel.Exchange;
import org.apache.camel.builder.RouteBuilder;
import org.apache.camel.component.reactive.streams.util.UnwrapStreamProcessor;
import org.reactivestreams.Publisher;
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 Camel can asynchronously request data to a reactive stream framework
 * and continue processing.
 *
 * The exchange pattern is in-out from Camel to Reactor.
 *
 * 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.camel-to-reactor-in-out")
public class BasicCamelToReactorInOutExample {

    /**
     * The reactor streams.
     */
    @Component("userBean")
    public static class BasicCamelToReactorInOutExampleStreams {

        /**
         * This method will be called by a Camel route.
         */
        public Publisher<UserInfo> getUserInfo(Publisher<Long> userId) {
            return Flux.from(userId)
                    .map(UserInfo::new)
                    .flatMap(this::retrieveAddress)
                    .flatMap(this::retrieveName);
        }

        /**
         * This is a sample utility method.
         */
        private Publisher<UserInfo> retrieveAddress(UserInfo user) {
            // you can do an async database retrieval here
            return Flux.just(user.withAddress("Address" + user.getId()));
        }

        private Publisher<UserInfo> retrieveName(UserInfo user) {
            // you can do an async database retrieval here
            return Flux.just(user.withName("Name" + user.getId()));
        }

    }


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

        @Override
        public void configure() throws Exception {

            // Generate a Id and retrieve user data from reactor
            from("timer:clock?period=9000&delay=1500")
                    .setBody().header(Exchange.TIMER_COUNTER).convertBodyTo(Long.class) // Sample ID
                    .bean("userBean", "getUserInfo") // Get the user info from reactor code
                    .process(new UnwrapStreamProcessor()) // Unwrap the Publisher
                    .log("BasicCamelToReactorInOut - Got ${body}");

        }

    }


    /**
     * Sample bean used in the example.
     */
    public static class UserInfo {

        private Long id;

        private String name;

        private String address;

        public UserInfo() {
        }

        public UserInfo(Long id) {
            this.id = id;
        }

        public Long getId() {
            return id;
        }

        public void setId(Long id) {
            this.id = id;
        }

        public String getName() {
            return name;
        }

        public void setName(String name) {
            this.name = name;
        }

        public UserInfo withName(String name) {
            this.name = name;
            return this;
        }

        public String getAddress() {
            return address;
        }

        public void setAddress(String address) {
            this.address = address;
        }

        public UserInfo withAddress(String address) {
            this.address = address;
            return this;
        }

        @Override
        public String toString() {
            final StringBuilder sb = new StringBuilder("UserInfo{");
            sb.append("id=").append(id);
            sb.append(", name='").append(name).append('\'');
            sb.append(", address='").append(address).append('\'');
            sb.append('}');
            return sb.toString();
        }
    }

}