    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.proxy;
    018
    019import org.apache.commons.pool2.ObjectPool;
    020import org.apache.commons.pool2.UsageTracking;
    021
    022/**
    023 * Create a new object pool where the pooled objects are wrapped in proxies
    024 * allowing better control of pooled objects and in particular the prevention
    025 * of the continued use of an object by a client after that client returns the
    026 * object to the pool.
    027 *
    028 * @param <T> type of the pooled object
    029 *
    030 * @since 2.0
    031 */
    032public class ProxiedObjectPool<T> implements ObjectPool<T> {
    033
    034    private final ObjectPool<T> pool;
    035    private final ProxySource<T> proxySource;
    036
    037
    038    /**
    039     * Constructs a new proxied object pool.
    040     *
    041     * @param pool  The object pool to wrap
    042     * @param proxySource The source of the proxy objects
    043     */
    044    public ProxiedObjectPool(final ObjectPool<T> pool, final ProxySource<T> proxySource) {
    045        this.pool = pool;
    046        this.proxySource = proxySource;
    047    }
    048
    049    @Override
    050    public void addObject() throws Exception {
    051        pool.addObject();
    052    }
    053
    054
    055    @SuppressWarnings("unchecked")
    056    @Override
    057    public T borrowObject() throws Exception {
    058        UsageTracking<T> usageTracking = null;
    059        if (pool instanceof UsageTracking) {
    060            usageTracking = (UsageTracking<T>) pool;
    061        }
    062        return proxySource.createProxy(pool.borrowObject(), usageTracking);
    063    }
    064
    065
    066    @Override
    067    public void clear() throws Exception {
    068        pool.clear();
    069    }
    070
    071
    072    @Override
    073    public void close() {
    074        pool.close();
    075    }
    076
    077
    078    @Override
    079    public int getNumActive() {
    080        return pool.getNumActive();
    081    }
    082
    083
    084    @Override
    085    public int getNumIdle() {
    086        return pool.getNumIdle();
    087    }
    088
    089
    090    @Override
    091    public void invalidateObject(final T proxy) throws Exception {
    092        pool.invalidateObject(proxySource.resolveProxy(proxy));
    093    }
    094
    095
    096    @Override
    097    public void returnObject(final T proxy) throws Exception {
    098        pool.returnObject(proxySource.resolveProxy(proxy));
    099    }
    100
    101    /**
    102     * @since 2.4.3
    103     */
    104    @Override
    105    public String toString() {
    106        final StringBuilder builder = new StringBuilder();
    107        builder.append("ProxiedObjectPool [pool=");
    108        builder.append(pool);
    109        builder.append(", proxySource=");
    110        builder.append(proxySource);
    111        builder.append("]");
    112        return builder.toString();
    113    }
    114}