Groovy example source code file (UnlimitedConcurrentCache.java)

This example Groovy source code file (UnlimitedConcurrentCache.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Groovy tags/keywords

concurrenthashmap, concurrenthashmap, memoizecache, object, object, softreference, softreference, threading, threads, unlimitedconcurrentcache, unlimitedconcurrentcache, util

The Groovy UnlimitedConcurrentCache.java source code

package org.codehaus.groovy.runtime.memoize;

import java.lang.ref.SoftReference;
import java.util.Iterator;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;

/**
 * A cache backed by a ConcurrentHashMap
 *
 * @author Vaclav Pech
 */
public final class UnlimitedConcurrentCache implements MemoizeCache<Object, Object> {

    private final ConcurrentHashMap<Object, Object> cache = new ConcurrentHashMap();

    public Object put(final Object key, final Object value) {
        return cache.put(key, value);
    }

    public Object get(final Object key) {
        return cache.get(key);
    }

    /**
     * Replying on the ConcurrentHashMap thread-safe iteration implementation the method will remove all entries holding
     * SoftReferences to gc-evicted objects.
     */
    public void cleanUpNullReferences() {
        final Iterator<Map.Entry iterator = cache.entrySet().iterator();
        while (iterator.hasNext()) {
            final Map.Entry<Object, Object> entry = iterator.next();
            Object entryVal = entry.getValue();
            if (entryVal != null && ((SoftReference) entryVal).get() == null) cache.remove(entry.getKey(), entryVal);
        }
    }
}