QNameCache.java
/*
* Copyright 2001-2005 (C) MetaStuff, Ltd. All Rights Reserved.
*
* This software is open source.
* See the bottom of this file for the licence.
*/
package org.dom4j.tree;
import org.dom4j.DocumentFactory;
import org.dom4j.Namespace;
import org.dom4j.QName;
import java.util.*;
/**
* <p>
* <code>QNameCache</code> caches instances of <code>QName</code> for reuse
* both across documents and within documents.
*
* @author <a href="mailto:james.strachan@metastuff.com">James Strachan </a>
* @version $Revision: 1.16 $
*
*/
public class QNameCache {
/** Cache of {@link QName}instances with no namespace */
protected Map<String, QName> noNamespaceCache = Collections.synchronizedMap(new WeakHashMap<String, QName>());
/**
* Cache of {@link Map}instances indexed by namespace which contain caches
* of {@link QName}for each name
*/
protected Map<Namespace, Map<String, QName>> namespaceCache = Collections.synchronizedMap(new WeakHashMap<Namespace, Map<String, QName>>());
/**
* The document factory associated with new QNames instances in this cache
* or null if no instances should be associated by default
*/
private DocumentFactory documentFactory;
public QNameCache() {
}
public QNameCache(DocumentFactory documentFactory) {
this.documentFactory = documentFactory;
}
/**
* Returns a list of all the QName instances currently used
*
* @return DOCUMENT ME!
*/
public List<QName> getQNames() {
List<QName> answer = new ArrayList<QName>();
synchronized(noNamespaceCache) {
answer.addAll(noNamespaceCache.values());
}
synchronized(namespaceCache) {
for (Map<String, QName> map : namespaceCache.values()) {
answer.addAll(map.values());
}
}
return answer;
}
/**
* DOCUMENT ME!
*
* @param name
* DOCUMENT ME!
*
* @return the QName for the given name and no namepsace
*/
public QName get(String name) {
QName answer = null;
if (name != null) {
answer = noNamespaceCache.get(name);
} else {
name = "";
}
if (answer == null) {
answer = createQName(name);
answer.setDocumentFactory(documentFactory);
noNamespaceCache.put(name, answer);
}
return answer;
}
/**
* DOCUMENT ME!
*
* @param name
* DOCUMENT ME!
* @param namespace
* DOCUMENT ME!
*
* @return the QName for the given local name and namepsace
*/
public QName get(String name, Namespace namespace) {
Map<String, QName> cache = getNamespaceCache(namespace);
QName answer = null;
if (name != null) {
answer = cache.get(name);
} else {
name = "";
}
if (answer == null) {
answer = createQName(name, namespace);
answer.setDocumentFactory(documentFactory);
cache.put(name, answer);
}
return answer;
}
/**
* DOCUMENT ME!
*
* @param localName
* DOCUMENT ME!
* @param namespace
* DOCUMENT ME!
* @param qName
* DOCUMENT ME!
*
* @return the QName for the given local name, qualified name and namepsace
*/
public QName get(String localName, Namespace namespace, String qName) {
Map<String, QName> cache = getNamespaceCache(namespace);
QName answer = null;
if (localName != null) {
answer = cache.get(localName);
} else {
localName = "";
}
if (answer == null) {
answer = createQName(localName, namespace, qName);
answer.setDocumentFactory(documentFactory);
cache.put(localName, answer);
}
return answer;
}
public QName get(String qualifiedName, String uri) {
int index = qualifiedName.indexOf(':');
if (index < 0) {
return get(qualifiedName, Namespace.get(uri));
} else if (index == 0){
throw new IllegalArgumentException("Qualified name cannot start with ':'.");
} else {
String name = qualifiedName.substring(index + 1);
String prefix = qualifiedName.substring(0, index);
return get(name, Namespace.get(prefix, uri));
}
}
/**
* DOCUMENT ME!
*
* @param qname
* DOCUMENT ME!
*
* @return the cached QName instance if there is one or adds the given qname
* to the cache if not
*/
public QName intern(QName qname) {
return get(qname.getName(), qname.getNamespace(), qname
.getQualifiedName());
}
/**
* DOCUMENT ME!
*
* @param namespace
* DOCUMENT ME!
*
* @return the cache for the given namespace. If one does not currently
* exist it is created.
*/
protected Map<String, QName> getNamespaceCache(Namespace namespace) {
if (namespace == Namespace.NO_NAMESPACE) {
return noNamespaceCache;
}
Map<String, QName> answer = null;
if (namespace != null) {
answer = namespaceCache.get(namespace);
}
if (answer == null) {
answer = createMap();
namespaceCache.put(namespace, answer);
}
return answer;
}
/**
* A factory method
*
* @return a newly created {@link Map}instance.
*/
protected Map<String, QName> createMap() {
return Collections.synchronizedMap(new HashMap<String, QName>());
}
/**
* Factory method to create a new QName object which can be overloaded to
* create derived QName instances
*
* @param name
* DOCUMENT ME!
*
* @return DOCUMENT ME!
*/
protected QName createQName(String name) {
return new QName(name);
}
/**
* Factory method to create a new QName object which can be overloaded to
* create derived QName instances
*
* @param name
* DOCUMENT ME!
* @param namespace
* DOCUMENT ME!
*
* @return DOCUMENT ME!
*/
protected QName createQName(String name, Namespace namespace) {
return new QName(name, namespace);
}
/**
* Factory method to create a new QName object which can be overloaded to
* create derived QName instances
*
* @param name
* DOCUMENT ME!
* @param namespace
* DOCUMENT ME!
* @param qualifiedName
* DOCUMENT ME!
*
* @return DOCUMENT ME!
*/
protected QName createQName(String name, Namespace namespace,
String qualifiedName) {
return new QName(name, namespace, qualifiedName);
}
}
/*
* Redistribution and use of this software and associated documentation
* ("Software"), with or without modification, are permitted provided that the
* following conditions are met:
*
* 1. Redistributions of source code must retain copyright statements and
* notices. Redistributions must also contain a copy of this document.
*
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* 3. The name "DOM4J" must not be used to endorse or promote products derived
* from this Software without prior written permission of MetaStuff, Ltd. For
* written permission, please contact dom4j-info@metastuff.com.
*
* 4. Products derived from this Software may not be called "DOM4J" nor may
* "DOM4J" appear in their names without prior written permission of MetaStuff,
* Ltd. DOM4J is a registered trademark of MetaStuff, Ltd.
*
* 5. Due credit should be given to the DOM4J Project - http://www.dom4j.org
*
* THIS SOFTWARE IS PROVIDED BY METASTUFF, LTD. AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL METASTUFF, LTD. OR ITS CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
* Copyright 2001-2005 (C) MetaStuff, Ltd. All Rights Reserved.
*/