a way for parallel process data in a Map.

ClusterAtomicActionsOnMapWithHazelcast.java

/**
 * Copyright (c) Experian, 2018. All rights reserved.
 */
package com.javadeveloperzone;

import com.hazelcast.core.HazelcastInstance;
import com.hazelcast.core.ILock;
import com.hazelcast.core.IMap;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;

import javax.annotation.PostConstruct;
import java.util.Calendar;
import java.util.Date;
import java.util.GregorianCalendar;
import java.util.Iterator;
import java.util.Map;
import java.util.Timer;
import java.util.TimerTask;
import java.util.UUID;

/**
 * @author Amir
 */
@Component
public class TestHazelcast {

    public static final String KEY = "key";
    @Autowired
    private HazelcastInstance instance;

    Logger logger = LoggerFactory.getLogger("Test");

    @PostConstruct
    public void init() {
        IMap<Object, Object> amir = instance.getMap("amir");
        for (int i = 0; i < 500; i++) {
            String mapKey = KEY + i;
            if (!amir.containsKey(mapKey)) {
                UUID val = UUID.randomUUID();
                amir.put(mapKey, val);
                logger.info("put value in map " + mapKey + ":" + val);
            }
        }
//        consumeCache(amir);
        System.out.println("amir = " + amir);
        Timer timer = new Timer();
        GregorianCalendar cal = new GregorianCalendar();
        cal.set(Calendar.MINUTE, Integer.parseInt(System.getProperty("fire.min", "48")));
        cal.set(Calendar.HOUR, cal.get(Calendar.HOUR));
        cal.set(Calendar.SECOND, 0);
        cal.set(Calendar.MILLISECOND, 0);
        timer.schedule(new TimerTask() {
            @Override
            public void run() {
                consumeCache(amir);
            }
        }, cal.getTime());
        logger.info("scheduled on " + cal.getTime());
    }

    private void consumeCache(final IMap<Object, Object> amir) {
        ILock lock = instance.getLock("lock");
        lock.lock();
        Iterator<Map.Entry<Object, Object>> iterator = amir.entrySet().iterator();
        while (iterator.hasNext()) {
            Map.Entry<Object, Object> next = iterator.next();
            logger.info("consumed " + next.getKey() + ":" + next.getValue());
            amir.remove(next.getKey());
            lock.unlock();
            lock.lock();
            iterator = amir.entrySet().iterator();
        }
        lock.unlock();
    }
}