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.UsageTracking;
020
021import net.sf.cglib.proxy.Enhancer;
022import net.sf.cglib.proxy.Factory;
023
024/**
025 * cglib is unmaintained and does not work well (or possibly at all?) in newer JDKs, particularly JDK17+; see https://github.com/cglib/cglib
026 * <p>
027 * Provides proxy objects using CGLib.
028 * </p>
029 *
030 * @param <T> type of the pooled object to be proxied
031 * @since 2.0
032 */
033public class CglibProxySource<T> implements ProxySource<T> {
034
035    private final Class<? extends T> superclass;
036
037    /**
038     * Constructs a new proxy source for the given class.
039     *
040     * @param superclass The class to proxy
041     */
042    public CglibProxySource(final Class<? extends T> superclass) {
043        this.superclass = superclass;
044    }
045
046    @SuppressWarnings("unchecked") // Case to T on return
047    @Override
048    public T createProxy(final T pooledObject, final UsageTracking<T> usageTracking) {
049        final Enhancer enhancer = new Enhancer();
050        enhancer.setSuperclass(superclass);
051
052        final CglibProxyHandler<T> proxyInterceptor =
053                new CglibProxyHandler<>(pooledObject, usageTracking);
054        enhancer.setCallback(proxyInterceptor);
055
056        return (T) enhancer.create();
057    }
058
059    @Override
060    public T resolveProxy(final T proxy) {
061        @SuppressWarnings("unchecked")
062        final
063        CglibProxyHandler<T> cglibProxyHandler =
064                (CglibProxyHandler<T>) ((Factory) proxy).getCallback(0);
065        return cglibProxyHandler.disableProxy();
066    }
067
068    /**
069     * @since 2.4.3
070     */
071    @Override
072    public String toString() {
073        final StringBuilder builder = new StringBuilder();
074        builder.append("CglibProxySource [superclass=");
075        builder.append(superclass);
076        builder.append("]");
077        return builder.toString();
078    }
079}