    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 java.util.NoSuchElementException;
    020
    021import org.apache.commons.pool2.KeyedObjectPool;
    022import org.apache.commons.pool2.UsageTracking;
    023
    024/**
    025 * Create a new keyed object pool where the pooled objects are wrapped in
    026 * proxies allowing better control of pooled objects and in particular the
    027 * prevention of the continued use of an object by a client after that client
    028 * returns the object to the pool.
    029 *
    030 * @param <K> type of the key
    031 * @param <V> type of the pooled object
    032 *
    033 * @since 2.0
    034 */
    035public class ProxiedKeyedObjectPool<K, V> implements KeyedObjectPool<K, V> {
    036
    037    private final KeyedObjectPool<K, V> pool;
    038    private final ProxySource<V> proxySource;
    039
    040
    041    /**
    042     * Create a new proxied object pool.
    043     *
    044     * @param pool  The object pool to wrap
    045     * @param proxySource The source of the proxy objects
    046     */
    047    public ProxiedKeyedObjectPool(final KeyedObjectPool<K, V> pool,
    048            final ProxySource<V> proxySource) {
    049        this.pool = pool;
    050        this.proxySource = proxySource;
    051    }
    052
    053
    054    @SuppressWarnings("unchecked")
    055    @Override
    056    public V borrowObject(final K key) throws Exception, NoSuchElementException,
    057            IllegalStateException {
    058        UsageTracking<V> usageTracking = null;
    059        if (pool instanceof UsageTracking) {
    060            usageTracking = (UsageTracking<V>) pool;
    061        }
    062        final V pooledObject = pool.borrowObject(key);
    063        final V proxy = proxySource.createProxy(pooledObject, usageTracking);
    064        return proxy;
    065    }
    066
    067    @Override
    068    public void returnObject(final K key, final V proxy) throws Exception {
    069        final V pooledObject = proxySource.resolveProxy(proxy);
    070        pool.returnObject(key, pooledObject);
    071    }
    072
    073    @Override
    074    public void invalidateObject(final K key, final V proxy) throws Exception {
    075        final V pooledObject = proxySource.resolveProxy(proxy);
    076        pool.invalidateObject(key, pooledObject);
    077    }
    078
    079    @Override
    080    public void addObject(final K key) throws Exception, IllegalStateException,
    081            UnsupportedOperationException {
    082        pool.addObject(key);
    083    }
    084
    085    @Override
    086    public int getNumIdle(final K key) {
    087        return pool.getNumIdle(key);
    088    }
    089
    090    @Override
    091    public int getNumActive(final K key) {
    092        return pool.getNumActive(key);
    093    }
    094
    095    @Override
    096    public int getNumIdle() {
    097        return pool.getNumIdle();
    098    }
    099
    100    @Override
    101    public int getNumActive() {
    102        return pool.getNumActive();
    103    }
    104
    105    @Override
    106    public void clear() throws Exception, UnsupportedOperationException {
    107        pool.clear();
    108    }
    109
    110    @Override
    111    public void clear(final K key) throws Exception, UnsupportedOperationException {
    112        pool.clear(key);
    113    }
    114
    115    @Override
    116    public void close() {
    117        pool.close();
    118    }
    119
    120
    121    /**
    122     * @since 2.4.3
    123     */
    124    @Override
    125    public String toString() {
    126        final StringBuilder builder = new StringBuilder();
    127        builder.append("ProxiedKeyedObjectPool [pool=");
    128        builder.append(pool);
    129        builder.append(", proxySource=");
    130        builder.append(proxySource);
    131        builder.append("]");
    132        return builder.toString();
    133    }
    134}