19f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson/* 29f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * Licensed to the Apache Software Foundation (ASF) under one 39f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * or more contributor license agreements. See the NOTICE file 49f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * distributed with this work for additional information 59f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * regarding copyright ownership. The ASF licenses this file 69f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * to you under the Apache License, Version 2.0 (the "License"); 79f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * you may not use this file except in compliance with the License. 89f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * You may obtain a copy of the License at 99f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * 109f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * http://www.apache.org/licenses/LICENSE-2.0 119f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * 129f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * Unless required by applicable law or agreed to in writing, software 139f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * distributed under the License is distributed on an "AS IS" BASIS, 149f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 159f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * See the License for the specific language governing permissions and 169f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * limitations under the License. 179f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson */ 189f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson/* 199f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * $Id: ObjectPool.java 475981 2006-11-16 23:35:53Z minchau $ 209f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson */ 219f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilsonpackage org.apache.xml.utils; 229f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 239f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilsonimport java.util.ArrayList; 249f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 259f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilsonimport org.apache.xml.res.XMLErrorResources; 269f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilsonimport org.apache.xml.res.XMLMessages; 279f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 289f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 299f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson/** 309f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * Pool of object of a given type to pick from to help memory usage 319f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * @xsl.usage internal 329f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson */ 339f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilsonpublic class ObjectPool implements java.io.Serializable 349f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson{ 359f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson static final long serialVersionUID = -8519013691660936643L; 369f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 379f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson /** Type of objects in this pool. 389f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * @serial */ 399f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson private final Class objectType; 409f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 419f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson /** Stack of given objects this points to. 429f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * @serial */ 439f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson private final ArrayList freeStack; 449f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 459f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson /** 469f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * Constructor ObjectPool 479f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * 489f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * @param type Type of objects for this pool 499f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson */ 509f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson public ObjectPool(Class type) 519f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson { 529f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson objectType = type; 539f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson freeStack = new ArrayList(); 549f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson } 559f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 569f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson /** 579f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * Constructor ObjectPool 589f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * 599f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * @param className Fully qualified name of the type of objects for this pool. 609f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson */ 619f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson public ObjectPool(String className) 629f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson { 639f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson try 649f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson { 659f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson objectType = ObjectFactory.findProviderClass( 669f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson className, ObjectFactory.findClassLoader(), true); 679f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson } 689f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson catch(ClassNotFoundException cnfe) 699f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson { 709f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson throw new WrappedRuntimeException(cnfe); 719f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson } 729f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson freeStack = new ArrayList(); 739f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson } 749f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 759f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 769f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson /** 779f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * Constructor ObjectPool 789f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * 799f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * 809f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * @param type Type of objects for this pool 819f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * @param size Size of vector to allocate 829f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson */ 839f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson public ObjectPool(Class type, int size) 849f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson { 859f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson objectType = type; 869f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson freeStack = new ArrayList(size); 879f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson } 889f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 899f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson /** 909f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * Constructor ObjectPool 919f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * 929f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson */ 939f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson public ObjectPool() 949f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson { 959f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson objectType = null; 969f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson freeStack = new ArrayList(); 979f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson } 989f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 999f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson /** 1009f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * Get an instance of the given object in this pool if available 1019f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * 1029f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * 1039f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * @return an instance of the given object if available or null 1049f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson */ 1059f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson public synchronized Object getInstanceIfFree() 1069f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson { 1079f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 1089f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson // Check if the pool is empty. 1099f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson if (!freeStack.isEmpty()) 1109f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson { 1119f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 1129f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson // Remove object from end of free pool. 1139f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson Object result = freeStack.remove(freeStack.size() - 1); 1149f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson return result; 1159f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson } 1169f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 1179f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson return null; 1189f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson } 1199f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 1209f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson /** 1219f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * Get an instance of the given object in this pool 1229f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * 1239f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * 1249f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * @return An instance of the given object 1259f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson */ 1269f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson public synchronized Object getInstance() 1279f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson { 1289f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 1299f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson // Check if the pool is empty. 1309f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson if (freeStack.isEmpty()) 1319f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson { 1329f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 1339f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson // Create a new object if so. 1349f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson try 1359f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson { 1369f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson return objectType.newInstance(); 1379f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson } 1389f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson catch (InstantiationException ex){} 1399f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson catch (IllegalAccessException ex){} 1409f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 1419f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson // Throw unchecked exception for error in pool configuration. 1429f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson throw new RuntimeException(XMLMessages.createXMLMessage(XMLErrorResources.ER_EXCEPTION_CREATING_POOL, null)); //"exception creating new instance for pool"); 1439f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson } 1449f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson else 1459f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson { 1469f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 1479f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson // Remove object from end of free pool. 1489f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson Object result = freeStack.remove(freeStack.size() - 1); 1499f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 1509f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson return result; 1519f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson } 1529f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson } 1539f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 1549f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson /** 1559f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * Add an instance of the given object to the pool 1569f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * 1579f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * 1589f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * @param obj Object to add. 1599f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson */ 1609f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson public synchronized void freeInstance(Object obj) 1619f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson { 1629f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 1639f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson // Make sure the object is of the correct type. 1649f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson // Remove safety. -sb 1659f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson // if (objectType.isInstance(obj)) 1669f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson // { 1679f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson freeStack.add(obj); 1689f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson // } 1699f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson // else 1709f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson // { 1719f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson // throw new IllegalArgumentException("argument type invalid for pool"); 1729f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson // } 1739f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson } 1749f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson} 175