org.openjdk.jmc.common.collection.EntryHashMap Maven / Gradle / Ivy

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package org.openjdk.jmc.common.collection;

import org.openjdk.jmc.common.collection.EntryHashMap.Entry;

/**
 * A map of Entry values (containing the key and the value) that can be subclassed to allow mapping
 * of mutable values. Note that the key values are final and may not be changed.
 *
 * @param 
 *            key type
 * @param 
 *            value type which has a reference to its key
 */
public abstract class EntryHashMap> extends KeyInValueMap {

	/**
	 * An entry in an EntryHashMap. Subclass to handle values.
	 *
	 * @param 
	 *            key type
	 */
	public abstract static class Entry {
		private final K key;

		/**
		 * Create an entry.
		 *
		 * @param key
		 *            the key corresponding to this entry
		 */
		public Entry(K key) {
			this.key = key;
		}

		/**
		 * Get the key.
		 *
		 * @return the key corresponding to this entry
		 */
		public K getKey() {
			return key;
		}
	}

	/**
	 * Create a new map.
	 *
	 * @param initialCapacity
	 *            initial storage capacity
	 * @param loadFactor
	 *            load factor at which to increase the internal storage capacity
	 */
	public EntryHashMap(int initialCapacity, float loadFactor) {
		super(initialCapacity, loadFactor);
	}

	@Override
	protected K getKey(V value) {
		return value.getKey();
	}
}