CollectionFactory.java

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 *
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package etm.core.util.collection;


import etm.core.util.collection.EDU.oswego.cs.dl.util.concurrent.ConcurrentReaderHashMap;

import java.util.Map;

/**
 * Helper class for runtime related collection access.
 *
 * @author void.fm
 * @version $Revision$
 * @since 1.2.1
 */
public abstract class CollectionFactory {

  private static CollectionFactory collectionFactory;

  public abstract Map newConcurrentHashMapInstance();

  public static CollectionFactory getInstance() {
    if (collectionFactory == null) {
      try {
        Class clazz = Class.forName("etm.core.util.collection.Java15CollectionFactory");
        collectionFactory = (CollectionFactory) clazz.newInstance();
      } catch (Throwable e) {
        collectionFactory = new DefaultCollectionFactory();
      }
    }

    return collectionFactory;
  }

  static class DefaultCollectionFactory extends CollectionFactory {
    public Map newConcurrentHashMapInstance() {
      // this one should work for VMs >= JDK 1.2
      return new ConcurrentReaderHashMap();
    }
  }
}