    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 * @see PooledObjectFactory
    030 * @see BaseKeyedPooledObjectFactory
    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     * invocation.</p>
    049     *
    050     * @return an instance to be served by the pool, not null.
    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) throws Exception  {
    063        // The default implementation is a no-op.
    064    }
    065
    066    @Override
    067    public PooledObject<T> makeObject() throws Exception {
    068        return wrap(Objects.requireNonNull(create(), () -> String.format("BasePooledObjectFactory(%s).create() = null", getClass().getName())));
    069    }
    070
    071    /**
    072     *  No-op.
    073     *
    074     * @param p ignored
    075     */
    076    @Override
    077    public void passivateObject(final PooledObject<T> p) throws Exception {
    078        // The default implementation is a no-op.
    079    }
    080
    081    /**
    082     * Always returns {@code true}.
    083     *
    084     * @param p ignored
    085     * @return {@code true}
    086     */
    087    @Override
    088    public boolean validateObject(final PooledObject<T> p) {
    089        return true;
    090    }
    091
    092    /**
    093     * Wraps the provided instance with an implementation of
    094     * {@link PooledObject}.
    095     *
    096     * @param obj the instance to wrap, should not be null.
    097     * @return The provided instance, wrapped by a {@link PooledObject}
    098     */
    099    public abstract PooledObject<T> wrap(T obj);
    100}