Observable Stream created from Infinispan Cache

CacheStream.java

/*
 * Copyright (c) 2015.
 * me@davengeo.com
 */

package org.daven.demo.rxcache;

import org.infinispan.Cache;
import org.infinispan.manager.DefaultCacheManager;
import org.infinispan.notifications.Listener;
import org.infinispan.notifications.cachelistener.annotation.CacheEntryModified;
import org.infinispan.notifications.cachelistener.event.CacheEntryModifiedEvent;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.stereotype.Component;
import rx.Observable;
import rx.Subscriber;
import rx.schedulers.Schedulers;

import javax.annotation.PostConstruct;
import java.util.EventListener;

@Component
public class CacheStream {

    private static Logger LOG = LoggerFactory.getLogger(CacheStream.class);

    Cache<String, String> cache;

    @PostConstruct
    public void init() {
        DefaultCacheManager defaultCacheManager = new DefaultCacheManager();
        defaultCacheManager.start();
        cache = defaultCacheManager.getCache("registry-1", true);
        cache.addListener(new EmitWhenChanged());
    }

    public void put(String value) {
        cache.put("one", value);
    }

    @Listener
    class EmitWhenChanged {

        @CacheEntryModified
        public void modified(CacheEntryModifiedEvent event) {
            LOG.info("value:{},pre:{},created:{}",
                    event.getValue(),
                    event.isPre(),
                    event.isCreated());
            if(!event.isPre()) {
                emitListener.emit((String) event.getValue());
            }
        }
    }

    private static EmitListener emitListener;

    private static Observable<String> stream = Observable.
            create((Subscriber<? super String> subscriber) -> {
                register(subscriber::onNext);
    }).subscribeOn(Schedulers.io());

    public static Observable<String> getStream() {
        return stream;
    }

    private static void register(EmitListener listener) {
        emitListener = listener;
    }

    private interface EmitListener extends EventListener {
        void emit(String str);
    }
}

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