org.apache.xml.security.utils.JDKXPathAPI Maven / Gradle / Ivy
/**
* 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.xml.security.utils;
import javax.xml.XMLConstants;
import javax.xml.transform.TransformerException;
import javax.xml.xpath.XPath;
import javax.xml.xpath.XPathConstants;
import javax.xml.xpath.XPathExpression;
import javax.xml.xpath.XPathExpressionException;
import javax.xml.xpath.XPathFactory;
import javax.xml.xpath.XPathFactoryConfigurationException;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
/**
* An implementation for XPath evaluation that uses the JDK API.
*/
public class JDKXPathAPI implements XPathAPI {
private XPathFactory xpf;
private String xpathStr;
private XPathExpression xpathExpression;
/**
* Use an XPath string to select a nodelist.
* XPath namespace prefixes are resolved from the namespaceNode.
*
* @param contextNode The node to start searching from.
* @param xpathnode
* @param str
* @param namespaceNode The node from which prefixes in the XPath will be resolved to namespaces.
* @return A NodeIterator, should never be null.
*
* @throws TransformerException
*/
public NodeList selectNodeList(
Node contextNode, Node xpathnode, String str, Node namespaceNode
) throws TransformerException {
if (!str.equals(xpathStr) || xpathExpression == null) {
if (xpf == null) {
xpf = XPathFactory.newInstance();
try {
xpf.setFeature(XMLConstants.FEATURE_SECURE_PROCESSING, Boolean.TRUE);
} catch (XPathFactoryConfigurationException ex) {
throw new TransformerException(ex);
}
}
XPath xpath = xpf.newXPath();
xpath.setNamespaceContext(new DOMNamespaceContext(namespaceNode));
xpathStr = str;
try {
xpathExpression = xpath.compile(xpathStr);
} catch (XPathExpressionException ex) {
throw new TransformerException(ex);
}
}
try {
return (NodeList)xpathExpression.evaluate(contextNode, XPathConstants.NODESET);
} catch (XPathExpressionException ex) {
throw new TransformerException(ex);
}
}
/**
* Evaluate an XPath string and return true if the output is to be included or not.
* @param contextNode The node to start searching from.
* @param xpathnode The XPath node
* @param str The XPath expression
* @param namespaceNode The node from which prefixes in the XPath will be resolved to namespaces.
*/
public boolean evaluate(Node contextNode, Node xpathnode, String str, Node namespaceNode)
throws TransformerException {
if (!str.equals(xpathStr) || xpathExpression == null) {
if (xpf == null) {
xpf = XPathFactory.newInstance();
try {
xpf.setFeature(XMLConstants.FEATURE_SECURE_PROCESSING, Boolean.TRUE);
} catch (XPathFactoryConfigurationException ex) {
throw new TransformerException(ex);
}
}
XPath xpath = xpf.newXPath();
xpath.setNamespaceContext(new DOMNamespaceContext(namespaceNode));
xpathStr = str;
try {
xpathExpression = xpath.compile(xpathStr);
} catch (XPathExpressionException ex) {
throw new TransformerException(ex);
}
}
try {
return (Boolean)xpathExpression.evaluate(contextNode, XPathConstants.BOOLEAN);
} catch (XPathExpressionException ex) {
throw new TransformerException(ex);
}
}
/**
* Clear any context information from this object
*/
public void clear() {
xpathStr = null;
xpathExpression = null;
xpf = null;
}
}