org.springone2gx_2011.integration.resequencer.ResequencerDemo.java Source code

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Here is the source code for org.springone2gx_2011.integration.resequencer.ResequencerDemo.java

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/*
 * Copyright 2002-2011 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.springone2gx_2011.integration.resequencer;

import java.util.Random;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.Executor;
import java.util.concurrent.Semaphore;

import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import org.springframework.integration.MessageChannel;
import org.springframework.integration.MessageHeaders;
import org.springframework.integration.annotation.Header;
import org.springframework.integration.support.MessageBuilder;

/**
 * @author Oleg Zhurakousky
 * SpringOne2GX, Chicago 2011
 */
public class ResequencerDemo {

    /**
     * @param args
     */
    public static void main(String[] args) throws Exception {
        ApplicationContext context = new ClassPathXmlApplicationContext("resequencer-config.xml",
                ResequencerDemo.class);
        MessageChannel inputChannel = context.getBean("inputChannel", MessageChannel.class);

        inputChannel.send(MessageBuilder.withPayload(5).setCorrelationId(1).setSequenceNumber(5).build());
        inputChannel.send(MessageBuilder.withPayload(2).setCorrelationId(1).setSequenceNumber(2).build());
        inputChannel.send(MessageBuilder.withPayload(1).setCorrelationId(1).setSequenceNumber(1).build());

        inputChannel.send(MessageBuilder.withPayload(2).setCorrelationId(2).setSequenceNumber(2).build());
        inputChannel.send(MessageBuilder.withPayload(1).setCorrelationId(2).setSequenceNumber(1).build());

        inputChannel.send(MessageBuilder.withPayload(4).setCorrelationId(1).setSequenceNumber(4).build());
        inputChannel.send(MessageBuilder.withPayload(3).setCorrelationId(1).setSequenceNumber(3).build());

        inputChannel.send(MessageBuilder.withPayload(5).setCorrelationId(2).setSequenceNumber(5).build());
        inputChannel.send(MessageBuilder.withPayload(4).setCorrelationId(2).setSequenceNumber(4).build());
        inputChannel.send(MessageBuilder.withPayload(3).setCorrelationId(2).setSequenceNumber(3).build());

        System.in.read();
    }

    public static class SequenceProcessor {

        private final ConcurrentHashMap<Object, Semaphore> locks = new ConcurrentHashMap<Object, Semaphore>();
        private final Random random = new Random();
        private final Executor taskExecutor;

        public SequenceProcessor(Executor taskExecutor) {
            this.taskExecutor = taskExecutor;
        }

        public void process(final Integer payload,
                final @Header(MessageHeaders.CORRELATION_ID) Object correlationId) throws Exception {
            locks.putIfAbsent(correlationId, new Semaphore(1, true));
            this.taskExecutor.execute(new Runnable() {
                public void run() {
                    try {
                        locks.get(correlationId).acquire();
                        System.out.println("Processing: " + payload + " correlationId: " + correlationId);
                        Thread.sleep(random.nextInt(2000));
                        locks.get(correlationId).release();
                    } catch (Exception e) {
                        e.printStackTrace();
                    }
                }
            });
        }
    }
}