/**
* 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.activemq.filter;
import java.io.StringReader;
import javax.jms.BytesMessage;
import javax.jms.JMSException;
import javax.jms.TextMessage;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.xpath.XPath;
import org.w3c.dom.Document;
import org.w3c.dom.traversal.NodeIterator;
import org.xml.sax.InputSource;
import org.apache.activemq.command.Message;
import org.apache.activemq.util.ByteArrayInputStream;
import org.apache.xpath.CachedXPathAPI;
import org.apache.xpath.objects.XObject;
public class XalanXPathEvaluator implements XPathExpression.XPathEvaluator {
private final String xpath;
public XalanXPathEvaluator(String xpath) {
this.xpath = xpath;
}
public boolean evaluate(Message m) throws JMSException {
if (m instanceof TextMessage) {
String text = ((TextMessage)m).getText();
return evaluate(text);
} else if (m instanceof BytesMessage) {
BytesMessage bm = (BytesMessage)m;
byte data[] = new byte[(int)bm.getBodyLength()];
bm.readBytes(data);
return evaluate(data);
}
return false;
}
private boolean evaluate(byte[] data) {
try {
InputSource inputSource = new InputSource(new ByteArrayInputStream(data));
DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
factory.setNamespaceAware(true);
DocumentBuilder dbuilder = factory.newDocumentBuilder();
Document doc = dbuilder.parse(inputSource);
CachedXPathAPI cachedXPathAPI = new CachedXPathAPI();
XObject result = cachedXPathAPI.eval(doc, xpath);
if (result.bool())
return true;
else {
NodeIterator iterator = cachedXPathAPI.selectNodeIterator(doc, xpath);
return (iterator.nextNode() != null);
}
} catch (Throwable e) {
return false;
}
}
private boolean evaluate(String text) {
try {
InputSource inputSource = new InputSource(new StringReader(text));
DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
factory.setNamespaceAware(true);
DocumentBuilder dbuilder = factory.newDocumentBuilder();
Document doc = dbuilder.parse(inputSource);
//An XPath expression could return a true or false value instead of a node.
//eval() is a better way to determine the boolean value of the exp.
//For compliance with legacy behavior where selecting an empty node returns true,
//selectNodeIterator is attempted in case of a failure.
CachedXPathAPI cachedXPathAPI = new CachedXPathAPI();
XObject result = cachedXPathAPI.eval(doc, xpath);
if (result.bool())
return true;
else {
NodeIterator iterator = cachedXPathAPI.selectNodeIterator(doc, xpath);
return (iterator.nextNode() != null);
}
} catch (Throwable e) {
return false;
}
}
}