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; 018 019/** 020 * A base implementation of <code>KeyedPooledObjectFactory</code>. 021 * <p> 022 * All operations defined here are essentially no-op's. 023 * </p> 024 * <p> 025 * This class is immutable, and therefore thread-safe. 026 * </p> 027 * 028 * @see KeyedPooledObjectFactory 029 * 030 * @param <K> The type of keys managed by this factory. 031 * @param <V> Type of element managed by this factory. 032 * 033 * @since 2.0 034 */ 035public abstract class BaseKeyedPooledObjectFactory<K, V> extends BaseObject 036 implements KeyedPooledObjectFactory<K, V> { 037 038 /** 039 * Create an instance that can be served by the pool. 040 * 041 * @param key the key used when constructing the object 042 * @return an instance that can be served by the pool 043 * 044 * @throws Exception if there is a problem creating a new instance, 045 * this will be propagated to the code requesting an object. 046 */ 047 public abstract V create(K key) 048 throws Exception; 049 050 /** 051 * Wrap the provided instance with an implementation of 052 * {@link PooledObject}. 053 * 054 * @param value the instance to wrap 055 * 056 * @return The provided instance, wrapped by a {@link PooledObject} 057 */ 058 public abstract PooledObject<V> wrap(V value); 059 060 @Override 061 public PooledObject<V> makeObject(final K key) throws Exception { 062 return wrap(create(key)); 063 } 064 065 /** 066 * Destroy an instance no longer needed by the pool. 067 * <p> 068 * The default implementation is a no-op. 069 * </p> 070 * 071 * @param key the key used when selecting the instance 072 * @param p a {@code PooledObject} wrapping the instance to be destroyed 073 */ 074 @Override 075 public void destroyObject(final K key, final PooledObject<V> p) 076 throws Exception { 077 // The default implementation is a no-op. 078 } 079 080 /** 081 * Ensures that the instance is safe to be returned by the pool. 082 * <p> 083 * The default implementation always returns {@code true}. 084 * </p> 085 * 086 * @param key the key used when selecting the object 087 * @param p a {@code PooledObject} wrapping the instance to be validated 088 * @return always <code>true</code> in the default implementation 089 */ 090 @Override 091 public boolean validateObject(final K key, final PooledObject<V> p) { 092 return true; 093 } 094 095 /** 096 * Reinitialize an instance to be returned by the pool. 097 * <p> 098 * The default implementation is a no-op. 099 * </p> 100 * 101 * @param key the key used when selecting the object 102 * @param p a {@code PooledObject} wrapping the instance to be activated 103 */ 104 @Override 105 public void activateObject(final K key, final PooledObject<V> p) 106 throws Exception { 107 // The default implementation is a no-op. 108 } 109 110 /** 111 * Uninitialize an instance to be returned to the idle object pool. 112 * <p> 113 * The default implementation is a no-op. 114 * </p> 115 * 116 * @param key the key used when selecting the object 117 * @param p a {@code PooledObject} wrapping the instance to be passivated 118 */ 119 @Override 120 public void passivateObject(final K key, final PooledObject<V> p) 121 throws Exception { 122 // The default implementation is a no-op. 123 } 124}