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}. 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 * Reinitialize an instance to be returned by the pool. 040 * <p> 041 * The default implementation is a no-op. 042 * </p> 043 * 044 * @param key the key used when selecting the object 045 * @param p a {@code PooledObject} wrapping the instance to be activated 046 */ 047 @Override 048 public void activateObject(final K key, final PooledObject<V> p) 049 throws Exception { 050 // The default implementation is a no-op. 051 } 052 053 /** 054 * Create an instance that can be served by the pool. 055 * 056 * @param key the key used when constructing the object 057 * @return an instance that can be served by the pool 058 * 059 * @throws Exception if there is a problem creating a new instance, 060 * this will be propagated to the code requesting an object. 061 */ 062 public abstract V create(K key) 063 throws Exception; 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 @Override 081 public PooledObject<V> makeObject(final K key) throws Exception { 082 return wrap(create(key)); 083 } 084 085 /** 086 * Uninitialize an instance to be returned to the idle object pool. 087 * <p> 088 * The default implementation is a no-op. 089 * </p> 090 * 091 * @param key the key used when selecting the object 092 * @param p a {@code PooledObject} wrapping the instance to be passivated 093 */ 094 @Override 095 public void passivateObject(final K key, final PooledObject<V> p) 096 throws Exception { 097 // The default implementation is a no-op. 098 } 099 100 /** 101 * Ensures that the instance is safe to be returned by the pool. 102 * <p> 103 * The default implementation always returns {@code true}. 104 * </p> 105 * 106 * @param key the key used when selecting the object 107 * @param p a {@code PooledObject} wrapping the instance to be validated 108 * @return always {@code true} in the default implementation 109 */ 110 @Override 111 public boolean validateObject(final K key, final PooledObject<V> p) { 112 return true; 113 } 114 115 /** 116 * Wrap the provided instance with an implementation of 117 * {@link PooledObject}. 118 * 119 * @param value the instance to wrap 120 * 121 * @return The provided instance, wrapped by a {@link PooledObject} 122 */ 123 public abstract PooledObject<V> wrap(V value); 124}