DefaultEvictionPolicy.java

  1. /*
  2.  * Licensed to the Apache Software Foundation (ASF) under one or more
  3.  * contributor license agreements.  See the NOTICE file distributed with
  4.  * this work for additional information regarding copyright ownership.
  5.  * The ASF licenses this file to You under the Apache License, Version 2.0
  6.  * (the "License"); you may not use this file except in compliance with
  7.  * the License.  You may obtain a copy of the License at
  8.  *
  9.  *      http://www.apache.org/licenses/LICENSE-2.0
  10.  *
  11.  * Unless required by applicable law or agreed to in writing, software
  12.  * distributed under the License is distributed on an "AS IS" BASIS,
  13.  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  14.  * See the License for the specific language governing permissions and
  15.  * limitations under the License.
  16.  */
  17. package org.apache.commons.pool2.impl;

  18. import org.apache.commons.pool2.PooledObject;

  19. /**
  20.  * Provides the default implementation of {@link EvictionPolicy} used by the pools.
  21.  * <p>
  22.  * Objects will be evicted if the following conditions are met:
  23.  * </p>
  24.  * <ul>
  25.  * <li>The object has been idle longer than
  26.  *     {@link GenericObjectPool#getMinEvictableIdleDuration()} /
  27.  *     {@link GenericKeyedObjectPool#getMinEvictableIdleDuration()}</li>
  28.  * <li>There are more than {@link GenericObjectPool#getMinIdle()} /
  29.  *     {@link GenericKeyedObjectPoolConfig#getMinIdlePerKey()} idle objects in
  30.  *     the pool and the object has been idle for longer than
  31.  *     {@link GenericObjectPool#getSoftMinEvictableIdleDuration()} /
  32.  *     {@link GenericKeyedObjectPool#getSoftMinEvictableIdleDuration()}
  33.  * </ul>
  34.  * <p>
  35.  * This class is immutable and thread-safe.
  36.  * </p>
  37.  *
  38.  * @param <T> the type of objects in the pool.
  39.  * @since 2.0
  40.  */
  41. public class DefaultEvictionPolicy<T> implements EvictionPolicy<T> {

  42.     /**
  43.      * Constructs a new instance.
  44.      */
  45.     public DefaultEvictionPolicy() {
  46.         // empty
  47.     }

  48.     @Override
  49.     public boolean evict(final EvictionConfig config, final PooledObject<T> underTest, final int idleCount) {
  50.         // @formatter:off
  51.         return config.getIdleSoftEvictDuration().compareTo(underTest.getIdleDuration()) < 0 &&
  52.                 config.getMinIdle() < idleCount ||
  53.                 config.getIdleEvictDuration().compareTo(underTest.getIdleDuration()) < 0;
  54.         // @formatter:on
  55.     }
  56. }