/*
* 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.xpath;
import java.io.Serializable;
import java.util.Collections;
import java.util.Comparator;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import org.dom4j.InvalidXPathException;
import org.dom4j.Node;
import org.dom4j.NodeFilter;
import org.dom4j.XPathException;
import org.jaxen.FunctionContext;
import org.jaxen.JaxenException;
import org.jaxen.NamespaceContext;
import org.jaxen.SimpleNamespaceContext;
import org.jaxen.VariableContext;
import org.jaxen.XPath;
import org.jaxen.dom4j.Dom4jXPath;
/**
* <p>
* Default implementation of {@link org.dom4j.XPath}which uses the <a
* href="http://jaxen.org">Jaxen </a> project.
* </p>
*
* @author bob mcwhirter
* @author <a href="mailto:jstrachan@apache.org">James Strachan </a>
*/
public class DefaultXPath implements org.dom4j.XPath, NodeFilter, Serializable {
private String text;
private XPath xpath;
private NamespaceContext namespaceContext;
/**
* Construct an XPath
*
* @param text
* DOCUMENT ME!
*
* @throws InvalidXPathException
* DOCUMENT ME!
*/
public DefaultXPath(String text) throws InvalidXPathException {
this.text = text;
this.xpath = parse(text);
}
public String toString() {
return "[XPath: " + xpath + "]";
}
// XPath interface
/**
* Retrieve the textual XPath string used to initialize this Object
*
* @return The XPath string
*/
public String getText() {
return text;
}
public FunctionContext getFunctionContext() {
return xpath.getFunctionContext();
}
public void setFunctionContext(FunctionContext functionContext) {
xpath.setFunctionContext(functionContext);
}
public NamespaceContext getNamespaceContext() {
return namespaceContext;
}
public void setNamespaceURIs(Map map) {
setNamespaceContext(new SimpleNamespaceContext(map));
}
public void setNamespaceContext(NamespaceContext namespaceContext) {
this.namespaceContext = namespaceContext;
xpath.setNamespaceContext(namespaceContext);
}
public VariableContext getVariableContext() {
return xpath.getVariableContext();
}
public void setVariableContext(VariableContext variableContext) {
xpath.setVariableContext(variableContext);
}
public Object evaluate(Object context) {
try {
setNSContext(context);
List answer = xpath.selectNodes(context);
if ((answer != null) && (answer.size() == 1)) {
return answer.get(0);
}
return answer;
} catch (JaxenException e) {
handleJaxenException(e);
return null;
}
}
public Object selectObject(Object context) {
return evaluate(context);
}
public List selectNodes(Object context) {
try {
setNSContext(context);
return xpath.selectNodes(context);
} catch (JaxenException e) {
handleJaxenException(e);
return Collections.EMPTY_LIST;
}
}
public List selectNodes(Object context, org.dom4j.XPath sortXPath) {
List answer = selectNodes(context);
sortXPath.sort(answer);
return answer;
}
public List selectNodes(Object context, org.dom4j.XPath sortXPath,
boolean distinct) {
List answer = selectNodes(context);
sortXPath.sort(answer, distinct);
return answer;
}
public Node selectSingleNode(Object context) {
try {
setNSContext(context);
Object answer = xpath.selectSingleNode(context);
if (answer instanceof Node) {
return (Node) answer;
}
if (answer == null) {
return null;
}
throw new XPathException("The result of the XPath expression is "
+ "not a Node. It was: " + answer + " of type: "
+ answer.getClass().getName());
} catch (JaxenException e) {
handleJaxenException(e);
return null;
}
}
public String valueOf(Object context) {
try {
setNSContext(context);
return xpath.stringValueOf(context);
} catch (JaxenException e) {
handleJaxenException(e);
return "";
}
}
public Number numberValueOf(Object context) {
try {
setNSContext(context);
return xpath.numberValueOf(context);
} catch (JaxenException e) {
handleJaxenException(e);
return null;
}
}
public boolean booleanValueOf(Object context) {
try {
setNSContext(context);
return xpath.booleanValueOf(context);
} catch (JaxenException e) {
handleJaxenException(e);
return false;
}
}
/**
* <p>
* <code>sort</code> sorts the given List of Nodes using this XPath
* expression as a {@link Comparator}.
* </p>
*
* @param list
* is the list of Nodes to sort
*/
public void sort(List list) {
sort(list, false);
}
/**
* <p>
* <code>sort</code> sorts the given List of Nodes using this XPath
* expression as a {@link Comparator}and optionally removing duplicates.
* </p>
*
* @param list
* is the list of Nodes to sort
* @param distinct
* if true then duplicate values (using the sortXPath for
* comparisions) will be removed from the List
*/
public void sort(List list, boolean distinct) {
if ((list != null) && !list.isEmpty()) {
int size = list.size();
HashMap sortValues = new HashMap(size);
for (int i = 0; i < size; i++) {
Object object = list.get(i);
if (object instanceof Node) {
Node node = (Node) object;
Object expression = getCompareValue(node);
sortValues.put(node, expression);
}
}
sort(list, sortValues);
if (distinct) {
removeDuplicates(list, sortValues);
}
}
}
public boolean matches(Node node) {
try {
setNSContext(node);
List answer = xpath.selectNodes(node);
if ((answer != null) && (answer.size() > 0)) {
Object item = answer.get(0);
if (item instanceof Boolean) {
return ((Boolean) item).booleanValue();
}
return answer.contains(node);
}
return false;
} catch (JaxenException e) {
handleJaxenException(e);
return false;
}
}
/**
* Sorts the list based on the sortValues for each node
*
* @param list
* DOCUMENT ME!
* @param sortValues
* DOCUMENT ME!
*/
protected void sort(List list, final Map sortValues) {
Collections.sort(list, new Comparator() {
public int compare(Object o1, Object o2) {
o1 = sortValues.get(o1);
o2 = sortValues.get(o2);
if (o1 == o2) {
return 0;
} else if (o1 instanceof Comparable) {
Comparable c1 = (Comparable) o1;
return c1.compareTo(o2);
} else if (o1 == null) {
return 1;
} else if (o2 == null) {
return -1;
} else {
return o1.equals(o2) ? 0 : (-1);
}
}
});
}
// Implementation methods
/**
* Removes items from the list which have duplicate values
*
* @param list
* DOCUMENT ME!
* @param sortValues
* DOCUMENT ME!
*/
protected void removeDuplicates(List list, Map sortValues) {
// remove distinct
HashSet distinctValues = new HashSet();
for (Iterator iter = list.iterator(); iter.hasNext();) {
Object node = iter.next();
Object value = sortValues.get(node);
if (distinctValues.contains(value)) {
iter.remove();
} else {
distinctValues.add(value);
}
}
}
/**
* DOCUMENT ME!
*
* @param node
* DOCUMENT ME!
*
* @return the node expression used for sorting comparisons
*/
protected Object getCompareValue(Node node) {
return valueOf(node);
}
protected static XPath parse(String text) {
try {
return new Dom4jXPath(text);
} catch (JaxenException e) {
throw new InvalidXPathException(text, e.getMessage());
} catch (Throwable t) {
throw new InvalidXPathException(text, t);
}
}
protected void setNSContext(Object context) {
if (namespaceContext == null) {
xpath.setNamespaceContext(DefaultNamespaceContext.create(context));
}
}
protected void handleJaxenException(JaxenException exception)
throws XPathException {
throw new XPathException(text, exception);
}
}
/*
* 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.
*/