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