    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
    019import java.util.Objects;
    020
    021/**
    022 * A base implementation of {@code PoolableObjectFactory}.
    023 * <p>
    024 * All operations defined here are essentially no-op's.
    025 * <p>
    026 * This class is immutable, and therefore thread-safe
    027 *
    028 * @param <T> Type of element managed in this factory.
    029 *
    030 * @see PooledObjectFactory
    031 * @see BaseKeyedPooledObjectFactory
    032 *
    033 * @since 2.0
    034 */
    035public abstract class BasePooledObjectFactory<T> extends BaseObject implements PooledObjectFactory<T> {
    036
    037    /**
    038     *  No-op.
    039     *
    040     *  @param p ignored
    041     */
    042    @Override
    043    public void activateObject(final PooledObject<T> p) throws Exception {
    044        // The default implementation is a no-op.
    045    }
    046
    047    /**
    048     * Creates an object instance, to be wrapped in a {@link PooledObject}.
    049     * <p>This method <strong>must</strong> support concurrent, multi-threaded
    050     * invocation.</p>
    051     *
    052     * @return an instance to be served by the pool, not null.
    053     *
    054     * @throws Exception if there is a problem creating a new instance,
    055     *    this will be propagated to the code requesting an object.
    056     */
    057    public abstract T create() throws Exception;
    058
    059    /**
    060     *  No-op.
    061     *
    062     *  @param p ignored
    063     */
    064    @Override
    065    public void destroyObject(final PooledObject<T> p) throws Exception  {
    066        // The default implementation is a no-op.
    067    }
    068
    069    @Override
    070    public PooledObject<T> makeObject() throws Exception {
    071        return wrap(Objects.requireNonNull(create(), () -> String.format("BasePooledObjectFactory(%s).create() = null", getClass().getName())));
    072    }
    073
    074    /**
    075     *  No-op.
    076     *
    077     * @param p ignored
    078     */
    079    @Override
    080    public void passivateObject(final PooledObject<T> p) 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, should not be null.
    101     *
    102     * @return The provided instance, wrapped by a {@link PooledObject}
    103     */
    104    public abstract PooledObject<T> wrap(T obj);
    105}