001 /** 002 * Licensed to the Apache Software Foundation (ASF) under one or more 003 * contributor license agreements. See the NOTICE file distributed with 004 * this work for additional information regarding copyright ownership. 005 * The ASF licenses this file to You under the Apache License, Version 2.0 006 * (the "License"); you may not use this file except in compliance with 007 * the License. You may obtain a copy of the License at 008 * 009 * http://www.apache.org/licenses/LICENSE-2.0 010 * 011 * Unless required by applicable law or agreed to in writing, software 012 * distributed under the License is distributed on an "AS IS" BASIS, 013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 014 * See the License for the specific language governing permissions and 015 * limitations under the License. 016 */ 017 018 package org.apache.activemq.filter; 019 020 import java.io.StringReader; 021 022 import javax.jms.BytesMessage; 023 import javax.jms.JMSException; 024 import javax.jms.TextMessage; 025 import javax.xml.parsers.DocumentBuilder; 026 import javax.xml.parsers.DocumentBuilderFactory; 027 import javax.xml.xpath.XPath; 028 029 import org.w3c.dom.Document; 030 import org.w3c.dom.traversal.NodeIterator; 031 import org.xml.sax.InputSource; 032 033 import org.apache.activemq.command.Message; 034 import org.apache.activemq.util.ByteArrayInputStream; 035 import org.apache.xpath.CachedXPathAPI; 036 import org.apache.xpath.objects.XObject; 037 038 039 public class XalanXPathEvaluator implements XPathExpression.XPathEvaluator { 040 041 private final String xpath; 042 043 public XalanXPathEvaluator(String xpath) { 044 this.xpath = xpath; 045 } 046 047 public boolean evaluate(Message m) throws JMSException { 048 if (m instanceof TextMessage) { 049 String text = ((TextMessage)m).getText(); 050 return evaluate(text); 051 } else if (m instanceof BytesMessage) { 052 BytesMessage bm = (BytesMessage)m; 053 byte data[] = new byte[(int)bm.getBodyLength()]; 054 bm.readBytes(data); 055 return evaluate(data); 056 } 057 return false; 058 } 059 060 private boolean evaluate(byte[] data) { 061 try { 062 063 InputSource inputSource = new InputSource(new ByteArrayInputStream(data)); 064 065 DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance(); 066 factory.setNamespaceAware(true); 067 DocumentBuilder dbuilder = factory.newDocumentBuilder(); 068 Document doc = dbuilder.parse(inputSource); 069 070 CachedXPathAPI cachedXPathAPI = new CachedXPathAPI(); 071 XObject result = cachedXPathAPI.eval(doc, xpath); 072 if (result.bool()) 073 return true; 074 else { 075 NodeIterator iterator = cachedXPathAPI.selectNodeIterator(doc, xpath); 076 return (iterator.nextNode() != null); 077 } 078 079 } catch (Throwable e) { 080 return false; 081 } 082 } 083 084 private boolean evaluate(String text) { 085 try { 086 InputSource inputSource = new InputSource(new StringReader(text)); 087 088 DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance(); 089 factory.setNamespaceAware(true); 090 DocumentBuilder dbuilder = factory.newDocumentBuilder(); 091 Document doc = dbuilder.parse(inputSource); 092 093 //An XPath expression could return a true or false value instead of a node. 094 //eval() is a better way to determine the boolean value of the exp. 095 //For compliance with legacy behavior where selecting an empty node returns true, 096 //selectNodeIterator is attempted in case of a failure. 097 098 CachedXPathAPI cachedXPathAPI = new CachedXPathAPI(); 099 XObject result = cachedXPathAPI.eval(doc, xpath); 100 if (result.bool()) 101 return true; 102 else { 103 NodeIterator iterator = cachedXPathAPI.selectNodeIterator(doc, xpath); 104 return (iterator.nextNode() != null); 105 } 106 107 } catch (Throwable e) { 108 return false; 109 } 110 } 111 }