    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 * To provide a custom eviction policy (i.e. something other than {@link
    023 * DefaultEvictionPolicy} for a pool, users must provide an implementation of
    024 * this interface that provides the required eviction policy.
    025 *
    026 * @param <T> the type of objects in the pool
    027 *
    028 * @version $Revision: $
    029 *
    030 * @since 2.0
    031 */
    032public interface EvictionPolicy<T> {
    033
    034    /**
    035     * This method is called to test if an idle object in the pool should be
    036     * evicted or not.
    037     *
    038     * @param config    The pool configuration settings related to eviction
    039     * @param underTest The pooled object being tested for eviction
    040     * @param idleCount The current number of idle objects in the pool including
    041     *                      the object under test
    042     * @return <code>true</code> if the object should be evicted, otherwise
    043     *             <code>false</code>
    044     */
    045    boolean evict(EvictionConfig config, PooledObject<T> underTest,
    046            int idleCount);
    047}