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    @Override
055    public void addObject(final K key) throws Exception, IllegalStateException,
056            UnsupportedOperationException {
057        pool.addObject(key);
058    }
059
060    @SuppressWarnings("unchecked")
061    @Override
062    public V borrowObject(final K key) throws Exception, NoSuchElementException,
063            IllegalStateException {
064        UsageTracking<V> usageTracking = null;
065        if (pool instanceof UsageTracking) {
066            usageTracking = (UsageTracking<V>) pool;
067        }
068        final V pooledObject = pool.borrowObject(key);
069        return proxySource.createProxy(pooledObject, usageTracking);
070    }
071
072    @Override
073    public void clear() throws Exception, UnsupportedOperationException {
074        pool.clear();
075    }
076
077    @Override
078    public void clear(final K key) throws Exception, UnsupportedOperationException {
079        pool.clear(key);
080    }
081
082    @Override
083    public void close() {
084        pool.close();
085    }
086
087    @Override
088    public int getNumActive() {
089        return pool.getNumActive();
090    }
091
092    @Override
093    public int getNumActive(final K key) {
094        return pool.getNumActive(key);
095    }
096
097    @Override
098    public int getNumIdle() {
099        return pool.getNumIdle();
100    }
101
102    @Override
103    public int getNumIdle(final K key) {
104        return pool.getNumIdle(key);
105    }
106
107    @Override
108    public void invalidateObject(final K key, final V proxy) throws Exception {
109        final V pooledObject = proxySource.resolveProxy(proxy);
110        pool.invalidateObject(key, pooledObject);
111    }
112
113    @Override
114    public void returnObject(final K key, final V proxy) throws Exception {
115        final V pooledObject = proxySource.resolveProxy(proxy);
116        pool.returnObject(key, pooledObject);
117    }
118
119
120    /**
121     * @since 2.4.3
122     */
123    @Override
124    public String toString() {
125        final StringBuilder builder = new StringBuilder();
126        builder.append("ProxiedKeyedObjectPool [pool=");
127        builder.append(pool);
128        builder.append(", proxySource=");
129        builder.append(proxySource);
130        builder.append("]");
131        return builder.toString();
132    }
133}