openjpa-lib/src/main/java/org/apache/openjpa/lib/meta/XMLMetaDataParser.java - openjpa - Git at Google

 /*
  * Licensed to the Apache Software Foundation (ASF) under one
  * or more contributor license agreements.  See the NOTICE file
  * distributed with this work for additional information
  * regarding copyright ownership.  The ASF licenses this file
  * to you under the Apache License, Version 2.0 (the
  * "License"); you may not use this file except in compliance
  * with the License.  You may obtain a copy of the License at
  *
  * http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing,
  * software distributed under the License is distributed on an
  * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
  * KIND, either express or implied.  See the License for the
  * specific language governing permissions and limitations
  * under the License.
  */
 package org.apache.openjpa.lib.meta;

 import java.io.File;
 import java.io.IOException;
 import java.io.InputStreamReader;
 import java.io.Reader;
 import java.net.URL;
 import java.security.AccessController;
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.LinkedList;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;

 import javax.xml.parsers.SAXParser;

 import org.apache.openjpa.lib.log.Log;
 import org.apache.openjpa.lib.util.J2DoPrivHelper;
 import org.apache.openjpa.lib.util.Localizer;
 import org.apache.openjpa.lib.util.Localizer.Message;
 import org.apache.openjpa.lib.xml.Commentable;
 import org.apache.openjpa.lib.xml.DocTypeReader;
 import org.apache.openjpa.lib.xml.Location;
 import org.apache.openjpa.lib.xml.XMLFactory;
 import org.xml.sax.Attributes;
 import org.xml.sax.InputSource;
 import org.xml.sax.Locator;
 import org.xml.sax.SAXException;
 import org.xml.sax.SAXParseException;
 import org.xml.sax.ext.LexicalHandler;
 import org.xml.sax.helpers.DefaultHandler;

 /**
  * Custom SAX parser used by the system to quickly parse metadata files.
  * Subclasses should handle the processing of the content.
  *
  * @author Abe White
  */
 public abstract class XMLMetaDataParser extends DefaultHandler
     implements LexicalHandler, MetaDataParser {

     private static final Localizer _loc = Localizer.forPackage
         (XMLMetaDataParser.class);
     private static boolean _schemaBug;

     private static final String OPENJPA_NAMESPACE = "http://openjpa.apache.org/ns/orm";
     protected int _extendedNamespace = 0;
     protected int _openjpaNamespace = 0;

     static {
         try {
             // check for Xerces version 2.0.2 to see if we need to disable
             // schema validation, which works around the bug reported at:
             // http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=4708859
             _schemaBug = "Xerces-J 2.0.2".equals(Class.forName
                 ("org.apache.xerces.impl.Version").getField("fVersion").
                 get(null));
         } catch (Throwable t) {
             // Xerces might not be available
             _schemaBug = false;
         }
     }

     // map of classloaders to sets of parsed locations, so that we don't parse
     // the same resource multiple times for the same class
     private Map<ClassLoader, Set<String>> _parsed = null;

     private Log _log = null;
     private boolean _validating = true;
     private boolean _systemId = true;
     private boolean _caching = true;
     private boolean _parseText = true;
     private boolean _parseComments = true;
     private String _suffix = null;
     private ClassLoader _loader = null;
     private ClassLoader _curLoader = null;

     // state for current parse
     private final Collection _curResults = new LinkedList();
     private List _results = null;
     private String _sourceName = null;
     private File _sourceFile = null;
     private StringBuffer _text = null;
     private List<String> _comments = null;
     private Location _location = new Location();
     private LexicalHandler _lh = null;
     private int _depth = -1;
     private int _ignore = Integer.MAX_VALUE;

     private boolean _parsing = false;

     private boolean _overrideContextClassloader = true;

     public boolean getOverrideContextClassloader() {
         return _overrideContextClassloader;
     }

     public void setOverrideContextClassloader(boolean overrideCCL) {
         _overrideContextClassloader = overrideCCL;
     }

     /*
      * Whether the parser is currently parsing.
      */
     public boolean isParsing() {
         return _parsing;
     }

     /*
      * Whether the parser is currently parsing.
      */
     public void setParsing(boolean parsing) {
         this._parsing = parsing;
     }

     /**
      * Whether to parse element text.
      */
     public boolean getParseText() {
         return _parseText;
     }

     /**
      * Whether to parse element text.
      */
     public void setParseText(boolean text) {
         _parseText = text;
     }

     /**
      * Whether to parse element comments.
      */
     public boolean getParseComments() {
         return _parseComments;
     }

     /**
      * Whether to parse element comments.
      */
     public void setParseComments(boolean comments) {
         _parseComments = comments;
     }

     /**
      * The XML document location.
      */
     public Location getLocation() {
         return _location;
     }

     /**
      * The lexical handler that should be registered with the SAX parser used
      * by this class. Since the <code>org.xml.sax.ext</code> package is not
      * a required part of SAX2, this handler might not be used by the parser.
      */
     public LexicalHandler getLexicalHandler() {
         return _lh;
     }

     /**
      * The lexical handler that should be registered with the SAX parser used
      * by this class. Since the <code>org.xml.sax.ext</code> package is not
      * a required part of SAX2, this handler might not be used by the parser.
      */
     public void setLexicalHandler(LexicalHandler lh) {
         _lh = lh;
     }

     /**
      * The XML document location.
      */
     public void setLocation(Location location) {
         _location = location;
     }

     /**
      * Whether to use the source name as the XML system id.
      */
     public boolean getSourceIsSystemId() {
         return _systemId;
     }

     /**
      * Whether to use the source name as the XML system id.
      */
     public void setSourceIsSystemId(boolean systemId) {
         _systemId = systemId;
     }

     /**
      * Whether this is a validating parser.
      */
     public boolean isValidating() {
         return _validating;
     }

     /**
      * Whether this is a validating parser.
      */
     public void setValidating(boolean validating) {
         _validating = validating;
     }

     /**
      * Expected suffix for metadata resources, or null if unknown.
      */
     public String getSuffix() {
         return _suffix;
     }

     /**
      * Expected suffix for metadata resources, or null if unknown.
      */
     public void setSuffix(String suffix) {
         _suffix = suffix;
     }

     /**
      * Whether parsed resource names are cached to avoid duplicate parsing.
      */
     public boolean isCaching() {
         return _caching;
     }

     /**
      * Whether parsed resource names are cached to avoid duplicate parsing.
      */
     public void setCaching(boolean caching) {
         _caching = caching;
         if (!caching)
             clear();
     }

     /**
      * The log to write to.
      */
     public Log getLog() {
         return _log;
     }

     /**
      * The log to write to.
      */
     public void setLog(Log log) {
         _log = log;
     }

     /**
      * Classloader to use for class name resolution.
      */
     public ClassLoader getClassLoader() {
         return _loader;
     }

     /**
      * Classloader to use for class name resolution.
      */
     @Override
     public void setClassLoader(ClassLoader loader) {
         _loader = loader;
     }

     @Override
     public List getResults() {
         if (_results == null)
             return Collections.emptyList();
         return _results;
     }

     @Override
     public void parse(String rsrc) throws IOException {
         if (rsrc != null)
             parse(new ResourceMetaDataIterator(rsrc, _loader));
     }

     @Override
     public void parse(URL url) throws IOException {
         if (url != null)
             parse(new URLMetaDataIterator(url));
     }

     @Override
     public void parse(File file) throws IOException {
         if (file == null)
             return;
         if (!AccessController.doPrivileged(J2DoPrivHelper
                 .isDirectoryAction(file)))
             parse(new FileMetaDataIterator(file));
         else {
             String suff = (_suffix == null) ? "" : _suffix;
             parse(new FileMetaDataIterator(file,
                 new SuffixMetaDataFilter(suff)));
         }
     }

     @Override
     public void parse(Class cls, boolean topDown) throws IOException {
         String suff = (_suffix == null) ? "" : _suffix;
         parse(new ClassMetaDataIterator(cls, suff, topDown), !topDown);
     }

     @Override
     public void parse(Reader xml, String sourceName) throws IOException {
         if (xml != null && (sourceName == null || !parsed(sourceName)))
             parseNewResource(xml, sourceName);
     }

     @Override
     public void parse(MetaDataIterator itr) throws IOException {
         parse(itr, false);
     }

     /**
      * Parse the resources returned by the given iterator, optionally stopping
      * when the first valid resource is found.
      */
     private void parse(MetaDataIterator itr, boolean stopFirst)
         throws IOException {
         if (itr == null)
             return;
         try {
             String sourceName;
             while (itr.hasNext()) {
                 sourceName = itr.next().toString();
                 if (parsed(sourceName)) {
                     if (stopFirst)
                         break;
                     continue;
                 }

                 // individual files of the resource might already be parsed
                 _sourceFile = itr.getFile();
                 parseNewResource(new InputStreamReader(itr.getInputStream()),
                     sourceName);
                 if (stopFirst)
                     break;
             }
         }
         finally {
             itr.close();
         }
     }

     /**
      * Parse a previously-unseen source. All parsing methods delegate
      * to this one.
      */
     protected void parseNewResource(Reader xml, String sourceName)
         throws IOException {
         if (_log != null && _log.isTraceEnabled())
             _log.trace(_loc.get("start-parse", sourceName));

         // even if we want to validate, specify that it won't happen
         // if we have neither a DocType not a Schema
         Object schemaSource = getSchemaSource();
         if (schemaSource != null && _schemaBug) {
             if (_log != null && _log.isTraceEnabled())
                 _log.trace(_loc.get("parser-schema-bug"));
             schemaSource = null;
         }
         boolean validating = _validating && (getDocType() != null
             || schemaSource != null);

         // parse the metadata with a SAX parser
         try {
             setParsing(true);
             _sourceName = sourceName;

             SAXParser parser = null;
             boolean overrideCL = _overrideContextClassloader;
             ClassLoader oldLoader = null;
             ClassLoader newLoader = null;

             try {
                 if (overrideCL) {
                     oldLoader =
                         (ClassLoader) AccessController.doPrivileged(J2DoPrivHelper.getContextClassLoaderAction());
                     newLoader = XMLMetaDataParser.class.getClassLoader();
                     AccessController.doPrivileged(J2DoPrivHelper.setContextClassLoaderAction(newLoader));

                     if (_log != null && _log.isTraceEnabled()) {
                         _log.trace(_loc.get("override-contextclassloader-begin", oldLoader, newLoader));
                     }
                 }

                 parser = XMLFactory.getSAXParser(validating, true);
                 Object schema = null;
                 if (validating) {
                     schema = schemaSource;
                     if (schema == null && getDocType() != null)
                         xml = new DocTypeReader(xml, getDocType());
                 }

                 if (_parseComments || _lh != null)
                     parser.setProperty
                         ("http://xml.org/sax/properties/lexical-handler", this);

                 if (schema != null) {
                     parser.setProperty
                         ("http://java.sun.com/xml/jaxp/properties/schemaLanguage",
                             "http://www.w3.org/2001/XMLSchema");
                     parser.setProperty
                         ("http://java.sun.com/xml/jaxp/properties/schemaSource",
                             schema);
                 }

                 InputSource is = new InputSource(xml);
                 if (_systemId && sourceName != null)
                     is.setSystemId(sourceName);
                 parser.parse(is, this);
                 finish();
             } catch (SAXException se) {
                 IOException ioe = new IOException(se.toString(), se);
                 throw ioe;
             } finally {
                 if (overrideCL) {
                     // Restore the old ContextClassloader
                     try {
                         if (_log != null && _log.isTraceEnabled()) {
                             _log.trace(_loc.get("override-contextclassloader-end", newLoader, oldLoader));
                         }
                         AccessController.doPrivileged(J2DoPrivHelper.setContextClassLoaderAction(oldLoader));
                     } catch (Throwable t) {
                         if (_log != null && _log.isWarnEnabled()) {
                             _log.warn(_loc.get("restore-contextclassloader-failed"));
                         }
                     }
                 }
             }
         } finally {
             reset();
         }
     }

     /**
      * Return true if the given source is parsed. Otherwise, record that
      * it will be parsed.
      */
     protected boolean parsed(String src) {
         if (!_caching)
             return false;
         if (_parsed == null)
             _parsed = new HashMap<>();

         ClassLoader loader = currentClassLoader();
         Set<String> set = _parsed.get(loader);
         if (set == null) {
             set = new HashSet<>();
             _parsed.put(loader, set);
         }
         boolean added = set.add(src);
         if (!added && _log != null && _log.isTraceEnabled())
             _log.trace(_loc.get("already-parsed", src));
         return !added;
     }

     @Override
     public void clear() {
         if (_log != null && _log.isTraceEnabled())
             _log.trace(_loc.get("clear-parser", this));
         if (_parsed != null)
             _parsed.clear();
     }

     @Override
     public void error(SAXParseException se) throws SAXException {
         throw getException(se.toString());
     }

     @Override
     public void fatalError(SAXParseException se) throws SAXException {
         throw getException(se.toString());
     }

     @Override
     public void setDocumentLocator(Locator locator) {
         _location.setLocator(locator);
     }

     @Override
     public void startElement(String uri, String name, String qName,
         Attributes attrs) throws SAXException {
         _depth++;
         if (_depth <= _ignore){
             if (uri.equals(OPENJPA_NAMESPACE)) {
                 _extendedNamespace++;
                 _openjpaNamespace++;
             }
             if (!startElement(qName, attrs))
                 ignoreContent(true);
         }
     }

     @Override
     public void endElement(String uri, String name, String qName)
         throws SAXException {
         if (_depth < _ignore) {
             endElement(qName);
             _extendedNamespace = (_extendedNamespace > 0) ? _extendedNamespace - 1 : 0;
             _openjpaNamespace = (_openjpaNamespace > 0) ? _openjpaNamespace - 1 : 0;
         }
         else if (_depth ==_ignore) {
             _extendedNamespace = (_extendedNamespace > 0) ? _extendedNamespace - 1 : 0;
             _openjpaNamespace = (_openjpaNamespace > 0) ? _openjpaNamespace - 1 : 0;
         }

         _text = null;
         if (_comments != null)
             _comments.clear();
         if (_depth == _ignore)
             _ignore = Integer.MAX_VALUE;
         _depth--;
     }

     @Override
     public void characters(char[] ch, int start, int length) {
         if (_parseText && _depth <= _ignore) {
             if (_text == null)
                 _text = new StringBuffer();
             _text.append(ch, start, length);
         }
     }

     @Override
     public void comment(char[] ch, int start, int length) throws SAXException {
         if (_parseComments && _depth <= _ignore) {
             if (_comments == null)
                 _comments = new ArrayList<>(3);
             _comments.add(String.valueOf(ch, start, length));
         }
         if (_lh != null)
             _lh.comment(ch, start, length);
     }

     @Override
     public void startCDATA() throws SAXException {
         if (_lh != null)
             _lh.startCDATA();
     }

     @Override
     public void endCDATA() throws SAXException {
         if (_lh != null)
             _lh.endCDATA();
     }

     @Override
     public void startDTD(String name, String publicId, String systemId)
         throws SAXException {
         if (_lh != null)
             _lh.startDTD(name, publicId, systemId);
     }

     @Override
     public void endDTD() throws SAXException {
         if (_lh != null)
             _lh.endDTD();
     }

     @Override
     public void startEntity(String name) throws SAXException {
         if (_lh != null)
             _lh.startEntity(name);
     }

     @Override
     public void endEntity(String name) throws SAXException {
         if (_lh != null)
             _lh.endEntity(name);
     }

     /**
      * Override this method marking the start of some element. If this method
      * returns false, the content of the element and the end element event will
      * be ignored.
      */
     protected abstract boolean startElement(String name, Attributes attrs)
         throws SAXException;

     /**
      * Override this method marking the end of some element.
      */
     protected abstract void endElement(String name) throws SAXException;

     /**
      * Add a result to be returned from the current parse.
      */
     protected void addResult(Object result) {
         if (_log != null && _log.isTraceEnabled())
             _log.trace(_loc.get("add-result", result));
         _curResults.add(result);
     }

     /**
      * Override this method to finish up after a parse; this is only
      * called if no errors are encountered during parsing. Subclasses should
      * call <code>super.finish()</code> to resolve superclass state.
      */
     protected void finish() {
         if (_log != null && _log.isTraceEnabled())
             _log.trace(_loc.get("end-parse", getSourceName()));
         _results = new ArrayList(_curResults);
     }

     /**
      * Override this method to clear any state and ready the parser for
      * a new document. Subclasses should call
      * <code>super.reset()</code> to clear superclass state.
      */
     protected void reset() {
         _curResults.clear();
         _curLoader = null;
         _sourceName = null;
         _sourceFile = null;
         _depth = -1;
         _ignore = Integer.MAX_VALUE;
         if (_comments != null)
             _comments.clear();
         clearDeferredMetaData();
         setParsing(false);
     }

     /**
      * Implement to return the XML schema source for the document. Returns
      * null by default. May return:
      * <ul>
      * <li><code>String</code> pointing to schema URI.</li>
      * <li><code>InputStream</code> containing schema contents.</li>
      * <li><code>InputSource</code> containing schema contents.</li>
      * <li><code>File</code> containing schema contents.</li>
      * <li>Array of any of the above elements.</li>
      * </ul>
      */
     protected Object getSchemaSource() throws IOException {
         return null;
     }

     /**
      * Override this method to return any <code>DOCTYPE</code> declaration
      * that should be dynamically included in xml documents that will be
      * validated. Returns null by default.
      */
     protected Reader getDocType() throws IOException {
         return null;
     }

     /**
      * Return the name of the source file being parsed.
      */
     protected String getSourceName() {
         return _sourceName;
     }

     /**
      * Return the file of the source being parsed.
      */
     protected File getSourceFile() {
         return _sourceFile;
     }

     /**
      * Add current comments to the given entity. By default, assumes entity
      * is {@link Commentable}.
      */
     protected void addComments(Object obj) {
         String[] comments = currentComments();
         if (comments.length > 0 && obj instanceof Commentable)
             ((Commentable) obj).setComments(comments);
     }

     /**
      * Array of comments for the current node, or empty array if none.
      */
     protected String[] currentComments() {
         if (_comments == null || _comments.isEmpty())
             return Commentable.EMPTY_COMMENTS;
         return _comments.toArray(new String[_comments.size()]);
     }

     /**
      * Return the text value within the current node.
      */
     protected String currentText() {
         if (_text == null)
             return "";
         return _text.toString().trim();
     }

     /**
      * Return the current location within the source file.
      */
     protected String currentLocation() {
         return " [" + _loc.get("loc-prefix") + _location.getLocation() + "]";
     }

     /**
      * Return the parse depth. Within the root element, the depth is 0,
      * within the first nested element, it is 1, and so forth.
      */
     protected int currentDepth() {
         return _depth;
     }

     /**
      * Return the class loader to use when resolving resources and loading
      * classes.
      */
     protected ClassLoader currentClassLoader() {
         if (_loader != null)
             return _loader;
         if (_curLoader == null)
             _curLoader = AccessController.doPrivileged(
                 J2DoPrivHelper.getContextClassLoaderAction());
         return _curLoader;
     }

     /**
      * Ignore all content below the current element.
      *
      * @param ignoreEnd whether to ignore the end element event
      */
     protected void ignoreContent(boolean ignoreEnd) {
         _ignore = _depth;
         if (!ignoreEnd)
             _ignore++;
     }

     /**
      * Returns a SAXException with the source file name and the given error
      * message.
      */
     protected SAXException getException(String msg) {
         return new SAXException(getSourceName() + currentLocation() +
             ": " + msg);
     }

     /**
      * Returns a SAXException with the source file name and the given error
      * message.
      */
     protected SAXException getException(Message msg) {
         return new SAXException(getSourceName() + currentLocation() +
             ": " + msg.getMessage());
     }

     /**
      * Returns a SAXException with the source file name and the given error
      * message.
      */
     protected SAXException getException(Message msg, Throwable cause) {
         if (cause != null && _log != null && _log.isTraceEnabled())
             _log.trace(_loc.get("sax-exception",
                 getSourceName(), _location.getLocation()), cause);
         SAXException e = new SAXException(getSourceName() + currentLocation() +
             ": " + msg + " [" + cause + "]");
         e.initCause(cause);
         return e;
     }

     protected void clearDeferredMetaData() {
     }
 }
	/*
	* Licensed to the Apache Software Foundation (ASF) under one
	* or more contributor license agreements. See the NOTICE file
	* distributed with this work for additional information
	* regarding copyright ownership. The ASF licenses this file
	* to you under the Apache License, Version 2.0 (the
	* "License"); you may not use this file except in compliance
	* with the License. You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing,
	* software distributed under the License is distributed on an
	* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
	* KIND, either express or implied. See the License for the
	* specific language governing permissions and limitations
	* under the License.
	*/
	package org.apache.openjpa.lib.meta;

	import java.io.File;
	import java.io.IOException;
	import java.io.InputStreamReader;
	import java.io.Reader;
	import java.net.URL;
	import java.security.AccessController;
	import java.util.ArrayList;
	import java.util.Collection;
	import java.util.Collections;
	import java.util.HashMap;
	import java.util.HashSet;
	import java.util.LinkedList;
	import java.util.List;
	import java.util.Map;
	import java.util.Set;

	import javax.xml.parsers.SAXParser;

	import org.apache.openjpa.lib.log.Log;
	import org.apache.openjpa.lib.util.J2DoPrivHelper;
	import org.apache.openjpa.lib.util.Localizer;
	import org.apache.openjpa.lib.util.Localizer.Message;
	import org.apache.openjpa.lib.xml.Commentable;
	import org.apache.openjpa.lib.xml.DocTypeReader;
	import org.apache.openjpa.lib.xml.Location;
	import org.apache.openjpa.lib.xml.XMLFactory;
	import org.xml.sax.Attributes;
	import org.xml.sax.InputSource;
	import org.xml.sax.Locator;
	import org.xml.sax.SAXException;
	import org.xml.sax.SAXParseException;
	import org.xml.sax.ext.LexicalHandler;
	import org.xml.sax.helpers.DefaultHandler;

	/**
	* Custom SAX parser used by the system to quickly parse metadata files.
	* Subclasses should handle the processing of the content.
	*
	* @author Abe White
	*/
	public abstract class XMLMetaDataParser extends DefaultHandler
	implements LexicalHandler, MetaDataParser {

	private static final Localizer _loc = Localizer.forPackage
	(XMLMetaDataParser.class);
	private static boolean _schemaBug;

	private static final String OPENJPA_NAMESPACE = "http://openjpa.apache.org/ns/orm";
	protected int _extendedNamespace = 0;
	protected int _openjpaNamespace = 0;

	static {
	try {
	// check for Xerces version 2.0.2 to see if we need to disable
	// schema validation, which works around the bug reported at:
	// http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=4708859
	_schemaBug = "Xerces-J 2.0.2".equals(Class.forName
	("org.apache.xerces.impl.Version").getField("fVersion").
	get(null));
	} catch (Throwable t) {
	// Xerces might not be available
	_schemaBug = false;
	}
	}

	// map of classloaders to sets of parsed locations, so that we don't parse
	// the same resource multiple times for the same class
	private Map<ClassLoader, Set<String>> _parsed = null;

	private Log _log = null;
	private boolean _validating = true;
	private boolean _systemId = true;
	private boolean _caching = true;
	private boolean _parseText = true;
	private boolean _parseComments = true;
	private String _suffix = null;
	private ClassLoader _loader = null;
	private ClassLoader _curLoader = null;

	// state for current parse
	private final Collection _curResults = new LinkedList();
	private List _results = null;
	private String _sourceName = null;
	private File _sourceFile = null;
	private StringBuffer _text = null;
	private List<String> _comments = null;
	private Location _location = new Location();
	private LexicalHandler _lh = null;
	private int _depth = -1;
	private int _ignore = Integer.MAX_VALUE;

	private boolean _parsing = false;

	private boolean _overrideContextClassloader = true;

	public boolean getOverrideContextClassloader() {
	return _overrideContextClassloader;
	}

	public void setOverrideContextClassloader(boolean overrideCCL) {
	_overrideContextClassloader = overrideCCL;
	}

	/*
	* Whether the parser is currently parsing.
	*/
	public boolean isParsing() {
	return _parsing;
	}

	/*
	* Whether the parser is currently parsing.
	*/
	public void setParsing(boolean parsing) {
	this._parsing = parsing;
	}

	/**
	* Whether to parse element text.
	*/
	public boolean getParseText() {
	return _parseText;
	}

	/**
	* Whether to parse element text.
	*/
	public void setParseText(boolean text) {
	_parseText = text;
	}

	/**
	* Whether to parse element comments.
	*/
	public boolean getParseComments() {
	return _parseComments;
	}

	/**
	* Whether to parse element comments.
	*/
	public void setParseComments(boolean comments) {
	_parseComments = comments;
	}

	/**
	* The XML document location.
	*/
	public Location getLocation() {
	return _location;
	}

	/**
	* The lexical handler that should be registered with the SAX parser used
	* by this class. Since the <code>org.xml.sax.ext</code> package is not
	* a required part of SAX2, this handler might not be used by the parser.
	*/
	public LexicalHandler getLexicalHandler() {
	return _lh;
	}

	/**
	* The lexical handler that should be registered with the SAX parser used
	* by this class. Since the <code>org.xml.sax.ext</code> package is not
	* a required part of SAX2, this handler might not be used by the parser.
	*/
	public void setLexicalHandler(LexicalHandler lh) {
	_lh = lh;
	}

	/**
	* The XML document location.
	*/
	public void setLocation(Location location) {
	_location = location;
	}

	/**
	* Whether to use the source name as the XML system id.
	*/
	public boolean getSourceIsSystemId() {
	return _systemId;
	}

	/**
	* Whether to use the source name as the XML system id.
	*/
	public void setSourceIsSystemId(boolean systemId) {
	_systemId = systemId;
	}

	/**
	* Whether this is a validating parser.
	*/
	public boolean isValidating() {
	return _validating;
	}

	/**
	* Whether this is a validating parser.
	*/
	public void setValidating(boolean validating) {
	_validating = validating;
	}

	/**
	* Expected suffix for metadata resources, or null if unknown.
	*/
	public String getSuffix() {
	return _suffix;
	}

	/**
	* Expected suffix for metadata resources, or null if unknown.
	*/
	public void setSuffix(String suffix) {
	_suffix = suffix;
	}

	/**
	* Whether parsed resource names are cached to avoid duplicate parsing.
	*/
	public boolean isCaching() {
	return _caching;
	}

	/**
	* Whether parsed resource names are cached to avoid duplicate parsing.
	*/
	public void setCaching(boolean caching) {
	_caching = caching;
	if (!caching)
	clear();
	}

	/**
	* The log to write to.
	*/
	public Log getLog() {
	return _log;
	}

	/**
	* The log to write to.
	*/
	public void setLog(Log log) {
	_log = log;
	}

	/**
	* Classloader to use for class name resolution.
	*/
	public ClassLoader getClassLoader() {
	return _loader;
	}

	/**
	* Classloader to use for class name resolution.
	*/
	@Override
	public void setClassLoader(ClassLoader loader) {
	_loader = loader;
	}

	@Override
	public List getResults() {
	if (_results == null)
	return Collections.emptyList();
	return _results;
	}

	@Override
	public void parse(String rsrc) throws IOException {
	if (rsrc != null)
	parse(new ResourceMetaDataIterator(rsrc, _loader));
	}

	@Override
	public void parse(URL url) throws IOException {
	if (url != null)
	parse(new URLMetaDataIterator(url));
	}

	@Override
	public void parse(File file) throws IOException {
	if (file == null)
	return;
	if (!AccessController.doPrivileged(J2DoPrivHelper
	.isDirectoryAction(file)))
	parse(new FileMetaDataIterator(file));
	else {
	String suff = (_suffix == null) ? "" : _suffix;
	parse(new FileMetaDataIterator(file,
	new SuffixMetaDataFilter(suff)));
	}
	}

	@Override
	public void parse(Class cls, boolean topDown) throws IOException {
	String suff = (_suffix == null) ? "" : _suffix;
	parse(new ClassMetaDataIterator(cls, suff, topDown), !topDown);
	}

	@Override
	public void parse(Reader xml, String sourceName) throws IOException {
	if (xml != null && (sourceName == null \|\| !parsed(sourceName)))
	parseNewResource(xml, sourceName);
	}

	@Override
	public void parse(MetaDataIterator itr) throws IOException {
	parse(itr, false);
	}

	/**
	* Parse the resources returned by the given iterator, optionally stopping
	* when the first valid resource is found.
	*/
	private void parse(MetaDataIterator itr, boolean stopFirst)
	throws IOException {
	if (itr == null)
	return;
	try {
	String sourceName;
	while (itr.hasNext()) {
	sourceName = itr.next().toString();
	if (parsed(sourceName)) {
	if (stopFirst)
	break;
	continue;
	}

	// individual files of the resource might already be parsed
	_sourceFile = itr.getFile();
	parseNewResource(new InputStreamReader(itr.getInputStream()),
	sourceName);
	if (stopFirst)
	break;
	}
	}
	finally {
	itr.close();
	}
	}

	/**
	* Parse a previously-unseen source. All parsing methods delegate
	* to this one.
	*/
	protected void parseNewResource(Reader xml, String sourceName)
	throws IOException {
	if (_log != null && _log.isTraceEnabled())
	_log.trace(_loc.get("start-parse", sourceName));

	// even if we want to validate, specify that it won't happen
	// if we have neither a DocType not a Schema
	Object schemaSource = getSchemaSource();
	if (schemaSource != null && _schemaBug) {
	if (_log != null && _log.isTraceEnabled())
	_log.trace(_loc.get("parser-schema-bug"));
	schemaSource = null;
	}
	boolean validating = _validating && (getDocType() != null
	\|\| schemaSource != null);

	// parse the metadata with a SAX parser
	try {
	setParsing(true);
	_sourceName = sourceName;

	SAXParser parser = null;
	boolean overrideCL = _overrideContextClassloader;
	ClassLoader oldLoader = null;
	ClassLoader newLoader = null;

	try {
	if (overrideCL) {
	oldLoader =
	(ClassLoader) AccessController.doPrivileged(J2DoPrivHelper.getContextClassLoaderAction());
	newLoader = XMLMetaDataParser.class.getClassLoader();
	AccessController.doPrivileged(J2DoPrivHelper.setContextClassLoaderAction(newLoader));

	if (_log != null && _log.isTraceEnabled()) {
	_log.trace(_loc.get("override-contextclassloader-begin", oldLoader, newLoader));
	}
	}

	parser = XMLFactory.getSAXParser(validating, true);
	Object schema = null;
	if (validating) {
	schema = schemaSource;
	if (schema == null && getDocType() != null)
	xml = new DocTypeReader(xml, getDocType());
	}

	if (_parseComments \|\| _lh != null)
	parser.setProperty
	("http://xml.org/sax/properties/lexical-handler", this);

	if (schema != null) {
	parser.setProperty
	("http://java.sun.com/xml/jaxp/properties/schemaLanguage",
	"http://www.w3.org/2001/XMLSchema");
	parser.setProperty
	("http://java.sun.com/xml/jaxp/properties/schemaSource",
	schema);
	}

	InputSource is = new InputSource(xml);
	if (_systemId && sourceName != null)
	is.setSystemId(sourceName);
	parser.parse(is, this);
	finish();
	} catch (SAXException se) {
	IOException ioe = new IOException(se.toString(), se);
	throw ioe;
	} finally {
	if (overrideCL) {
	// Restore the old ContextClassloader
	try {
	if (_log != null && _log.isTraceEnabled()) {
	_log.trace(_loc.get("override-contextclassloader-end", newLoader, oldLoader));
	}
	AccessController.doPrivileged(J2DoPrivHelper.setContextClassLoaderAction(oldLoader));
	} catch (Throwable t) {
	if (_log != null && _log.isWarnEnabled()) {
	_log.warn(_loc.get("restore-contextclassloader-failed"));
	}
	}
	}
	}
	} finally {
	reset();
	}
	}

	/**
	* Return true if the given source is parsed. Otherwise, record that
	* it will be parsed.
	*/
	protected boolean parsed(String src) {
	if (!_caching)
	return false;
	if (_parsed == null)
	_parsed = new HashMap<>();

	ClassLoader loader = currentClassLoader();
	Set<String> set = _parsed.get(loader);
	if (set == null) {
	set = new HashSet<>();
	_parsed.put(loader, set);
	}
	boolean added = set.add(src);
	if (!added && _log != null && _log.isTraceEnabled())
	_log.trace(_loc.get("already-parsed", src));
	return !added;
	}

	@Override
	public void clear() {
	if (_log != null && _log.isTraceEnabled())
	_log.trace(_loc.get("clear-parser", this));
	if (_parsed != null)
	_parsed.clear();
	}

	@Override
	public void error(SAXParseException se) throws SAXException {
	throw getException(se.toString());
	}

	@Override
	public void fatalError(SAXParseException se) throws SAXException {
	throw getException(se.toString());
	}

	@Override
	public void setDocumentLocator(Locator locator) {
	_location.setLocator(locator);
	}

	@Override
	public void startElement(String uri, String name, String qName,
	Attributes attrs) throws SAXException {
	_depth++;
	if (_depth <= _ignore){
	if (uri.equals(OPENJPA_NAMESPACE)) {
	_extendedNamespace++;
	_openjpaNamespace++;
	}
	if (!startElement(qName, attrs))
	ignoreContent(true);
	}
	}

	@Override
	public void endElement(String uri, String name, String qName)
	throws SAXException {
	if (_depth < _ignore) {
	endElement(qName);
	_extendedNamespace = (_extendedNamespace > 0) ? _extendedNamespace - 1 : 0;
	_openjpaNamespace = (_openjpaNamespace > 0) ? _openjpaNamespace - 1 : 0;
	}
	else if (_depth ==_ignore) {
	_extendedNamespace = (_extendedNamespace > 0) ? _extendedNamespace - 1 : 0;
	_openjpaNamespace = (_openjpaNamespace > 0) ? _openjpaNamespace - 1 : 0;
	}

	_text = null;
	if (_comments != null)
	_comments.clear();
	if (_depth == _ignore)
	_ignore = Integer.MAX_VALUE;
	_depth--;
	}

	@Override
	public void characters(char[] ch, int start, int length) {
	if (_parseText && _depth <= _ignore) {
	if (_text == null)
	_text = new StringBuffer();
	_text.append(ch, start, length);
	}
	}

	@Override
	public void comment(char[] ch, int start, int length) throws SAXException {
	if (_parseComments && _depth <= _ignore) {
	if (_comments == null)
	_comments = new ArrayList<>(3);
	_comments.add(String.valueOf(ch, start, length));
	}
	if (_lh != null)
	_lh.comment(ch, start, length);
	}

	@Override
	public void startCDATA() throws SAXException {
	if (_lh != null)
	_lh.startCDATA();
	}

	@Override
	public void endCDATA() throws SAXException {
	if (_lh != null)
	_lh.endCDATA();
	}

	@Override
	public void startDTD(String name, String publicId, String systemId)
	throws SAXException {
	if (_lh != null)
	_lh.startDTD(name, publicId, systemId);
	}

	@Override
	public void endDTD() throws SAXException {
	if (_lh != null)
	_lh.endDTD();
	}

	@Override
	public void startEntity(String name) throws SAXException {
	if (_lh != null)
	_lh.startEntity(name);
	}

	@Override
	public void endEntity(String name) throws SAXException {
	if (_lh != null)
	_lh.endEntity(name);
	}

	/**
	* Override this method marking the start of some element. If this method
	* returns false, the content of the element and the end element event will
	* be ignored.
	*/
	protected abstract boolean startElement(String name, Attributes attrs)
	throws SAXException;

	/**
	* Override this method marking the end of some element.
	*/
	protected abstract void endElement(String name) throws SAXException;

	/**
	* Add a result to be returned from the current parse.
	*/
	protected void addResult(Object result) {
	if (_log != null && _log.isTraceEnabled())
	_log.trace(_loc.get("add-result", result));
	_curResults.add(result);
	}

	/**
	* Override this method to finish up after a parse; this is only
	* called if no errors are encountered during parsing. Subclasses should
	* call <code>super.finish()</code> to resolve superclass state.
	*/
	protected void finish() {
	if (_log != null && _log.isTraceEnabled())
	_log.trace(_loc.get("end-parse", getSourceName()));
	_results = new ArrayList(_curResults);
	}

	/**
	* Override this method to clear any state and ready the parser for
	* a new document. Subclasses should call
	* <code>super.reset()</code> to clear superclass state.
	*/
	protected void reset() {
	_curResults.clear();
	_curLoader = null;
	_sourceName = null;
	_sourceFile = null;
	_depth = -1;
	_ignore = Integer.MAX_VALUE;
	if (_comments != null)
	_comments.clear();
	clearDeferredMetaData();
	setParsing(false);
	}

	/**
	* Implement to return the XML schema source for the document. Returns
	* null by default. May return:
	* <ul>
	* <li><code>String</code> pointing to schema URI.</li>
	* <li><code>InputStream</code> containing schema contents.</li>
	* <li><code>InputSource</code> containing schema contents.</li>
	* <li><code>File</code> containing schema contents.</li>
	* <li>Array of any of the above elements.</li>
	* </ul>
	*/
	protected Object getSchemaSource() throws IOException {
	return null;
	}

	/**
	* Override this method to return any <code>DOCTYPE</code> declaration
	* that should be dynamically included in xml documents that will be
	* validated. Returns null by default.
	*/
	protected Reader getDocType() throws IOException {
	return null;
	}

	/**
	* Return the name of the source file being parsed.
	*/
	protected String getSourceName() {
	return _sourceName;
	}

	/**
	* Return the file of the source being parsed.
	*/
	protected File getSourceFile() {
	return _sourceFile;
	}

	/**
	* Add current comments to the given entity. By default, assumes entity
	* is {@link Commentable}.
	*/
	protected void addComments(Object obj) {
	String[] comments = currentComments();
	if (comments.length > 0 && obj instanceof Commentable)
	((Commentable) obj).setComments(comments);
	}

	/**
	* Array of comments for the current node, or empty array if none.
	*/
	protected String[] currentComments() {
	if (_comments == null \|\| _comments.isEmpty())
	return Commentable.EMPTY_COMMENTS;
	return _comments.toArray(new String[_comments.size()]);
	}

	/**
	* Return the text value within the current node.
	*/
	protected String currentText() {
	if (_text == null)
	return "";
	return _text.toString().trim();
	}

	/**
	* Return the current location within the source file.
	*/
	protected String currentLocation() {
	return " [" + _loc.get("loc-prefix") + _location.getLocation() + "]";
	}

	/**
	* Return the parse depth. Within the root element, the depth is 0,
	* within the first nested element, it is 1, and so forth.
	*/
	protected int currentDepth() {
	return _depth;
	}

	/**
	* Return the class loader to use when resolving resources and loading
	* classes.
	*/
	protected ClassLoader currentClassLoader() {
	if (_loader != null)
	return _loader;
	if (_curLoader == null)
	_curLoader = AccessController.doPrivileged(
	J2DoPrivHelper.getContextClassLoaderAction());
	return _curLoader;
	}

	/**
	* Ignore all content below the current element.
	*
	* @param ignoreEnd whether to ignore the end element event
	*/
	protected void ignoreContent(boolean ignoreEnd) {
	_ignore = _depth;
	if (!ignoreEnd)
	_ignore++;
	}

	/**
	* Returns a SAXException with the source file name and the given error
	* message.
	*/
	protected SAXException getException(String msg) {
	return new SAXException(getSourceName() + currentLocation() +
	": " + msg);
	}

	/**
	* Returns a SAXException with the source file name and the given error
	* message.
	*/
	protected SAXException getException(Message msg) {
	return new SAXException(getSourceName() + currentLocation() +
	": " + msg.getMessage());
	}

	/**
	* Returns a SAXException with the source file name and the given error
	* message.
	*/
	protected SAXException getException(Message msg, Throwable cause) {
	if (cause != null && _log != null && _log.isTraceEnabled())
	_log.trace(_loc.get("sax-exception",
	getSourceName(), _location.getLocation()), cause);
	SAXException e = new SAXException(getSourceName() + currentLocation() +
	": " + msg + " [" + cause + "]");
	e.initCause(cause);
	return e;
	}

	protected void clearDeferredMetaData() {
	}
	}