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 PoolableObjectFactory}.
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 * @param <T> Type of element managed in this factory.
027 *
028 * @see PooledObjectFactory
029 * @see BaseKeyedPooledObjectFactory
030 *
031 * @since 2.0
032 */
033public abstract class BasePooledObjectFactory<T> extends BaseObject implements PooledObjectFactory<T> {
034
035    /**
036     *  No-op.
037     *
038     *  @param p ignored
039     */
040    @Override
041    public void activateObject(final PooledObject<T> p) throws Exception {
042        // The default implementation is a no-op.
043    }
044
045    /**
046     * Creates an object instance, to be wrapped in a {@link PooledObject}.
047     * <p>This method <strong>must</strong> support concurrent, multi-threaded
048     * activation.</p>
049     *
050     * @return an instance to be served by the pool
051     *
052     * @throws Exception if there is a problem creating a new instance,
053     *    this will be propagated to the code requesting an object.
054     */
055    public abstract T create() throws Exception;
056
057    /**
058     *  No-op.
059     *
060     *  @param p ignored
061     */
062    @Override
063    public void destroyObject(final PooledObject<T> p)
064        throws Exception  {
065        // The default implementation is a no-op.
066    }
067
068    @Override
069    public PooledObject<T> makeObject() throws Exception {
070        return wrap(create());
071    }
072
073    /**
074     *  No-op.
075     *
076     * @param p ignored
077     */
078    @Override
079    public void passivateObject(final PooledObject<T> p)
080        throws Exception {
081        // The default implementation is a no-op.
082    }
083
084    /**
085     * Always returns {@code true}.
086     *
087     * @param p ignored
088     *
089     * @return {@code true}
090     */
091    @Override
092    public boolean validateObject(final PooledObject<T> p) {
093        return true;
094    }
095
096    /**
097     * Wraps the provided instance with an implementation of
098     * {@link PooledObject}.
099     *
100     * @param obj the instance to wrap
101     *
102     * @return The provided instance, wrapped by a {@link PooledObject}
103     */
104    public abstract PooledObject<T> wrap(T obj);
105}