/*
* Copyright 2005-2014 the original author or authors.
*
* Licensed 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.springframework.xml.xpath;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import javax.xml.namespace.QName;
import javax.xml.xpath.XPath;
import javax.xml.xpath.XPathConstants;
import javax.xml.xpath.XPathExpressionException;
import javax.xml.xpath.XPathFactory;
import org.w3c.dom.DOMException;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.springframework.xml.namespace.SimpleNamespaceContext;
/**
* JAXP 1.3-specific factory creating {@link XPathExpression} objects.
*
* @author Arjen Poutsma
* @see #createXPathExpression(String)
* @since 1.0.0
*/
abstract class Jaxp13XPathExpressionFactory {
private static XPathFactory xpathFactory = XPathFactory.newInstance();
/**
* Creates a JAXP 1.3 {@code XPathExpression} from the given string expression.
*
* @param expression the XPath expression
* @return the compiled {@code XPathExpression}
* @throws XPathParseException when the given expression cannot be parsed
*/
static XPathExpression createXPathExpression(String expression) {
try {
XPath xpath = createXPath();
javax.xml.xpath.XPathExpression xpathExpression = xpath.compile(expression);
return new Jaxp13XPathExpression(xpathExpression);
}
catch (XPathExpressionException ex) {
throw new org.springframework.xml.xpath.XPathParseException(
"Could not compile [" + expression + "] to a XPathExpression: " + ex.getMessage(), ex);
}
}
/**
* Creates a JAXP 1.3 {@code XPathExpression} from the given string expression and namespaces.
*
* @param expression the XPath expression
* @param namespaces the namespaces
* @return the compiled {@code XPathExpression}
* @throws XPathParseException when the given expression cannot be parsed
*/
public static XPathExpression createXPathExpression(String expression, Map<String, String> namespaces) {
try {
XPath xpath = createXPath();
SimpleNamespaceContext namespaceContext = new SimpleNamespaceContext();
namespaceContext.setBindings(namespaces);
xpath.setNamespaceContext(namespaceContext);
javax.xml.xpath.XPathExpression xpathExpression = xpath.compile(expression);
return new Jaxp13XPathExpression(xpathExpression);
}
catch (XPathExpressionException ex) {
throw new org.springframework.xml.xpath.XPathParseException(
"Could not compile [" + expression + "] to a XPathExpression: " + ex.getMessage(), ex);
}
}
private static synchronized XPath createXPath() {
return xpathFactory.newXPath();
}
/** JAXP 1.3 implementation of the {@code XPathExpression} interface. */
private static class Jaxp13XPathExpression implements XPathExpression {
private final javax.xml.xpath.XPathExpression xpathExpression;
private Jaxp13XPathExpression(javax.xml.xpath.XPathExpression xpathExpression) {
this.xpathExpression = xpathExpression;
}
@Override
public String evaluateAsString(Node node) {
return (String) evaluate(node, XPathConstants.STRING);
}
@Override
public List<Node> evaluateAsNodeList(Node node) {
NodeList nodeList = (NodeList) evaluate(node, XPathConstants.NODESET);
return toNodeList(nodeList);
}
private Object evaluate(Node node, QName returnType) {
try {
// XPathExpression is not thread-safe
synchronized (xpathExpression) {
return xpathExpression.evaluate(node, returnType);
}
}
catch (XPathExpressionException ex) {
throw new XPathException("Could not evaluate XPath expression:" + ex.getMessage(), ex);
}
}
private List<Node> toNodeList(NodeList nodeList) {
List<Node> result = new ArrayList<Node>(nodeList.getLength());
for (int i = 0; i < nodeList.getLength(); i++) {
result.add(nodeList.item(i));
}
return result;
}
@Override
public double evaluateAsNumber(Node node) {
return (Double) evaluate(node, XPathConstants.NUMBER);
}
@Override
public boolean evaluateAsBoolean(Node node) {
return (Boolean) evaluate(node, XPathConstants.BOOLEAN);
}
@Override
public Node evaluateAsNode(Node node) {
return (Node) evaluate(node, XPathConstants.NODE);
}
@Override
public <T> T evaluateAsObject(Node node, NodeMapper<T> nodeMapper) throws XPathException {
Node result = (Node) evaluate(node, XPathConstants.NODE);
if (result != null) {
try {
return nodeMapper.mapNode(result, 0);
}
catch (DOMException ex) {
throw new XPathException("Mapping resulted in DOMException", ex);
}
}
else {
return null;
}
}
@Override
public <T> List<T> evaluate(Node node, NodeMapper<T> nodeMapper) throws XPathException {
NodeList nodes = (NodeList) evaluate(node, XPathConstants.NODESET);
List<T> results = new ArrayList<T>(nodes.getLength());
for (int i = 0; i < nodes.getLength(); i++) {
try {
results.add(nodeMapper.mapNode(nodes.item(i), i));
}
catch (DOMException ex) {
throw new XPathException("Mapping resulted in DOMException", ex);
}
}
return results;
}
}
}