001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017package org.apache.commons.pool2;
018
019/**
020 * A base implementation of <code>KeyedPooledObjectFactory</code>.
021 * <p>
022 * All operations defined here are essentially no-op's.
023 * </p>
024 * This class is immutable, and therefore thread-safe.
025 *
026 * @see KeyedPooledObjectFactory
027 *
028 * @param <K> The type of keys managed by this factory.
029 * @param <V> Type of element managed by this factory.
030 *
031 * @version $Revision: 1333925 $
032 *
033 * @since 2.0
034 */
035public abstract class BaseKeyedPooledObjectFactory<K,V>
036        implements KeyedPooledObjectFactory<K,V> {
037
038    /**
039     * Create an instance that can be served by the pool.
040     *
041     * @param key the key used when constructing the object
042     * @return an instance that can be served by the pool
043     */
044    public abstract V create(K key)
045        throws Exception;
046
047    /**
048     * Wrap the provided instance with an implementation of
049     * {@link PooledObject}.
050     *
051     * @param value the instance to wrap
052     *
053     * @return The provided instance, wrapped by a {@link PooledObject}
054     */
055    public abstract PooledObject<V> wrap(V value);
056
057    @Override
058    public PooledObject<V> makeObject(K key) throws Exception {
059        return wrap(create(key));
060    }
061
062    /**
063     * Destroy an instance no longer needed by the pool.
064     * <p>
065     * The default implementation is a no-op.
066     *
067     * @param key the key used when selecting the instance
068     * @param p a {@code PooledObject} wrapping the the instance to be destroyed
069     */
070    @Override
071    public void destroyObject(K key, PooledObject<V> p)
072        throws Exception {
073    }
074
075    /**
076     * Ensures that the instance is safe to be returned by the pool.
077     * <p>
078     * The default implementation always returns <tt>true</tt>.
079     *
080     * @param key the key used when selecting the object
081     * @param p a {@code PooledObject} wrapping the the instance to be validated
082     * @return always <code>true</code> in the default implementation
083     */
084    @Override
085    public boolean validateObject(K key, PooledObject<V> p) {
086        return true;
087    }
088
089    /**
090     * Reinitialize an instance to be returned by the pool.
091     * <p>
092     * The default implementation is a no-op.
093     *
094     * @param key the key used when selecting the object
095     * @param p a {@code PooledObject} wrapping the the instance to be activated
096     */
097    @Override
098    public void activateObject(K key, PooledObject<V> p)
099        throws Exception {
100    }
101
102    /**
103     * Uninitialize an instance to be returned to the idle object pool.
104     * <p>
105     * The default implementation is a no-op.
106     *
107     * @param key the key used when selecting the object
108     * @param p a {@code PooledObject} wrapping the the instance to be passivated
109     */
110    @Override
111    public void passivateObject(K key, PooledObject<V> p)
112        throws Exception {
113    }
114}