14c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson/* 24c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson * Licensed to the Apache Software Foundation (ASF) under one 34c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson * or more contributor license agreements. See the NOTICE file 44c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson * distributed with this work for additional information 54c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson * regarding copyright ownership. The ASF licenses this file 64c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson * to you under the Apache License, Version 2.0 (the "License"); 74c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson * you may not use this file except in compliance with the License. 84c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson * You may obtain a copy of the License at 94c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson * 104c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson * http://www.apache.org/licenses/LICENSE-2.0 114c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson * 124c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson * Unless required by applicable law or agreed to in writing, software 134c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson * distributed under the License is distributed on an "AS IS" BASIS, 144c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 154c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson * See the License for the specific language governing permissions and 164c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson * limitations under the License. 174c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson */ 184c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson/* 194c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson * $Id: ObjectPool.java 475981 2006-11-16 23:35:53Z minchau $ 204c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson */ 214c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilsonpackage org.apache.xml.utils; 224c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson 234c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilsonimport java.util.ArrayList; 244c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson 254c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilsonimport org.apache.xml.res.XMLErrorResources; 264c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilsonimport org.apache.xml.res.XMLMessages; 274c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson 284c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson 294c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson/** 304c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson * Pool of object of a given type to pick from to help memory usage 314c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson * @xsl.usage internal 324c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson */ 334c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilsonpublic class ObjectPool implements java.io.Serializable 344c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson{ 354c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson static final long serialVersionUID = -8519013691660936643L; 364c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson 374c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson /** Type of objects in this pool. 384c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson * @serial */ 394c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson private final Class objectType; 404c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson 414c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson /** Stack of given objects this points to. 424c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson * @serial */ 434c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson private final ArrayList freeStack; 444c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson 454c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson /** 464c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson * Constructor ObjectPool 474c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson * 484c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson * @param type Type of objects for this pool 494c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson */ 504c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson public ObjectPool(Class type) 514c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson { 524c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson objectType = type; 534c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson freeStack = new ArrayList(); 544c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson } 554c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson 564c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson /** 574c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson * Constructor ObjectPool 584c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson * 594c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson * @param className Fully qualified name of the type of objects for this pool. 604c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson */ 614c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson public ObjectPool(String className) 624c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson { 634c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson try 644c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson { 654c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson objectType = ObjectFactory.findProviderClass( 664c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson className, ObjectFactory.findClassLoader(), true); 674c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson } 684c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson catch(ClassNotFoundException cnfe) 694c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson { 704c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson throw new WrappedRuntimeException(cnfe); 714c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson } 724c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson freeStack = new ArrayList(); 734c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson } 744c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson 754c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson 764c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson /** 774c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson * Constructor ObjectPool 784c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson * 794c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson * 804c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson * @param type Type of objects for this pool 814c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson * @param size Size of vector to allocate 824c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson */ 834c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson public ObjectPool(Class type, int size) 844c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson { 854c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson objectType = type; 864c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson freeStack = new ArrayList(size); 874c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson } 884c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson 894c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson /** 904c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson * Constructor ObjectPool 914c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson * 924c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson */ 934c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson public ObjectPool() 944c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson { 954c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson objectType = null; 964c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson freeStack = new ArrayList(); 974c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson } 984c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson 994c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson /** 1004c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson * Get an instance of the given object in this pool if available 1014c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson * 1024c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson * 1034c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson * @return an instance of the given object if available or null 1044c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson */ 1054c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson public synchronized Object getInstanceIfFree() 1064c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson { 1074c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson 1084c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson // Check if the pool is empty. 1094c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson if (!freeStack.isEmpty()) 1104c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson { 1114c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson 1124c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson // Remove object from end of free pool. 1134c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson Object result = freeStack.remove(freeStack.size() - 1); 1144c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson return result; 1154c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson } 1164c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson 1174c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson return null; 1184c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson } 1194c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson 1204c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson /** 1214c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson * Get an instance of the given object in this pool 1224c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson * 1234c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson * 1244c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson * @return An instance of the given object 1254c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson */ 1264c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson public synchronized Object getInstance() 1274c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson { 1284c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson 1294c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson // Check if the pool is empty. 1304c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson if (freeStack.isEmpty()) 1314c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson { 1324c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson 1334c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson // Create a new object if so. 1344c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson try 1354c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson { 1364c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson return objectType.newInstance(); 1374c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson } 1384c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson catch (InstantiationException ex){} 1394c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson catch (IllegalAccessException ex){} 1404c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson 1414c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson // Throw unchecked exception for error in pool configuration. 1424c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson throw new RuntimeException(XMLMessages.createXMLMessage(XMLErrorResources.ER_EXCEPTION_CREATING_POOL, null)); //"exception creating new instance for pool"); 1434c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson } 1444c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson else 1454c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson { 1464c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson 1474c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson // Remove object from end of free pool. 1484c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson Object result = freeStack.remove(freeStack.size() - 1); 1494c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson 1504c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson return result; 1514c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson } 1524c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson } 1534c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson 1544c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson /** 1554c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson * Add an instance of the given object to the pool 1564c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson * 1574c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson * 1584c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson * @param obj Object to add. 1594c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson */ 1604c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson public synchronized void freeInstance(Object obj) 1614c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson { 1624c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson 1634c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson // Make sure the object is of the correct type. 1644c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson // Remove safety. -sb 1654c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson // if (objectType.isInstance(obj)) 1664c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson // { 1674c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson freeStack.add(obj); 1684c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson // } 1694c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson // else 1704c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson // { 1714c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson // throw new IllegalArgumentException("argument type invalid for pool"); 1724c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson // } 1734c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson } 1744c7a0d97cf2b27790e6236965a1d798d710d7ec7Jesse Wilson} 175