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.impl;
018
019import org.apache.commons.pool2.PooledObject;
020
021/**
022 * Provides the default implementation of {@link EvictionPolicy} used by the pools.
023 * <p>
024 * Objects will be evicted if the following conditions are met:
025 * </p>
026 * <ul>
027 * <li>The object has been idle longer than
028 *     {@link GenericObjectPool#getMinEvictableIdleDuration()} /
029 *     {@link GenericKeyedObjectPool#getMinEvictableIdleDuration()}</li>
030 * <li>There are more than {@link GenericObjectPool#getMinIdle()} /
031 *     {@link GenericKeyedObjectPoolConfig#getMinIdlePerKey()} idle objects in
032 *     the pool and the object has been idle for longer than
033 *     {@link GenericObjectPool#getSoftMinEvictableIdleDuration()} /
034 *     {@link GenericKeyedObjectPool#getSoftMinEvictableIdleDuration()}
035 * </ul>
036 * <p>
037 * This class is immutable and thread-safe.
038 * </p>
039 *
040 * @param <T> the type of objects in the pool.
041 *
042 * @since 2.0
043 */
044public class DefaultEvictionPolicy<T> implements EvictionPolicy<T> {
045
046    @Override
047    public boolean evict(final EvictionConfig config, final PooledObject<T> underTest, final int idleCount) {
048        // @formatter:off
049        return (config.getIdleSoftEvictDuration().compareTo(underTest.getIdleDuration()) < 0 &&
050                config.getMinIdle() < idleCount) ||
051                config.getIdleEvictDuration().compareTo(underTest.getIdleDuration()) < 0;
052        // @formatter:on
053    }
054}