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: XMLReaderManager.java 468655 2006-10-28 07:12:06Z minchau $ 209f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson */ 219f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilsonpackage org.apache.xml.utils; 229f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 239f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilsonimport java.util.Hashtable; 249f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 259f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilsonimport javax.xml.parsers.FactoryConfigurationError; 269f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilsonimport javax.xml.parsers.ParserConfigurationException; 279f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilsonimport javax.xml.parsers.SAXParserFactory; 289f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 299f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilsonimport org.xml.sax.XMLReader; 309f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilsonimport org.xml.sax.helpers.XMLReaderFactory; 319f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilsonimport org.xml.sax.SAXException; 329f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 339f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson/** 349f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * Creates XMLReader objects and caches them for re-use. 359f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * This class follows the singleton pattern. 369f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson */ 379f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilsonpublic class XMLReaderManager { 389f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 399f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson private static final String NAMESPACES_FEATURE = 409f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson "http://xml.org/sax/features/namespaces"; 419f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson private static final String NAMESPACE_PREFIXES_FEATURE = 429f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson "http://xml.org/sax/features/namespace-prefixes"; 439f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson private static final XMLReaderManager m_singletonManager = 449f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson new XMLReaderManager(); 459f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 469f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson /** 479f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * Parser factory to be used to construct XMLReader objects 489f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson */ 499f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson private static SAXParserFactory m_parserFactory; 509f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 519f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson /** 529f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * Cache of XMLReader objects 539f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson */ 549f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson private ThreadLocal m_readers; 559f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 569f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson /** 579f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * Keeps track of whether an XMLReader object is in use. 589f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson */ 599f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson private Hashtable m_inUse; 609f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 619f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson /** 629f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * Hidden constructor 639f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson */ 649f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson private XMLReaderManager() { 659f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson } 669f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 679f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson /** 689f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * Retrieves the singleton reader manager 699f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson */ 709f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson public static XMLReaderManager getInstance() { 719f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson return m_singletonManager; 729f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson } 739f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 749f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson /** 759f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * Retrieves a cached XMLReader for this thread, or creates a new 769f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * XMLReader, if the existing reader is in use. When the caller no 779f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * longer needs the reader, it must release it with a call to 789f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * {@link #releaseXMLReader}. 799f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson */ 809f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson public synchronized XMLReader getXMLReader() throws SAXException { 819f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson XMLReader reader; 829f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson boolean readerInUse; 839f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 849f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson if (m_readers == null) { 859f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson // When the m_readers.get() method is called for the first time 869f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson // on a thread, a new XMLReader will automatically be created. 879f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson m_readers = new ThreadLocal(); 889f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson } 899f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 909f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson if (m_inUse == null) { 919f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson m_inUse = new Hashtable(); 929f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson } 939f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 949f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson // If the cached reader for this thread is in use, construct a new 959f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson // one; otherwise, return the cached reader. 969f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson reader = (XMLReader) m_readers.get(); 979f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson boolean threadHasReader = (reader != null); 989f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson if (!threadHasReader || m_inUse.get(reader) == Boolean.TRUE) { 999f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson try { 1009f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson try { 1019f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson // According to JAXP 1.2 specification, if a SAXSource 1029f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson // is created using a SAX InputSource the Transformer or 1039f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson // TransformerFactory creates a reader via the 1049f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson // XMLReaderFactory if setXMLReader is not used 1059f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson reader = XMLReaderFactory.createXMLReader(); 1069f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson } catch (Exception e) { 1079f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson try { 1089f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson // If unable to create an instance, let's try to use 1099f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson // the XMLReader from JAXP 1109f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson if (m_parserFactory == null) { 1119f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson m_parserFactory = SAXParserFactory.newInstance(); 1129f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson m_parserFactory.setNamespaceAware(true); 1139f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson } 1149f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 1159f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson reader = m_parserFactory.newSAXParser().getXMLReader(); 1169f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson } catch (ParserConfigurationException pce) { 1179f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson throw pce; // pass along pce 1189f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson } 1199f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson } 1209f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson try { 1219f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson reader.setFeature(NAMESPACES_FEATURE, true); 1229f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson reader.setFeature(NAMESPACE_PREFIXES_FEATURE, false); 1239f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson } catch (SAXException se) { 1249f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson // Try to carry on if we've got a parser that 1259f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson // doesn't know about namespace prefixes. 1269f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson } 1279f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson } catch (ParserConfigurationException ex) { 1289f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson throw new SAXException(ex); 1299f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson } catch (FactoryConfigurationError ex1) { 1309f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson throw new SAXException(ex1.toString()); 1319f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson } catch (NoSuchMethodError ex2) { 1329f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson } catch (AbstractMethodError ame) { 1339f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson } 1349f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 1359f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson // Cache the XMLReader if this is the first time we've created 1369f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson // a reader for this thread. 1379f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson if (!threadHasReader) { 1389f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson m_readers.set(reader); 1399f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson m_inUse.put(reader, Boolean.TRUE); 1409f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson } 1419f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson } else { 1429f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson m_inUse.put(reader, Boolean.TRUE); 1439f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson } 1449f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 1459f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson return reader; 1469f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson } 1479f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 1489f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson /** 1499f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * Mark the cached XMLReader as available. If the reader was not 1509f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * actually in the cache, do nothing. 1519f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * 1529f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * @param reader The XMLReader that's being released. 1539f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson */ 1549f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson public synchronized void releaseXMLReader(XMLReader reader) { 1559f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson // If the reader that's being released is the cached reader 1569f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson // for this thread, remove it from the m_isUse list. 1579f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson if (m_readers.get() == reader && reader != null) { 1589f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson m_inUse.remove(reader); 1599f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson } 1609f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson } 1619f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson} 162