| /* |
| * 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. |
| */ |
| /* |
| * $Id$ |
| */ |
| // This file uses 4 space indents, no tabs. |
| |
| import java.io.FileInputStream; |
| import java.io.OutputStreamWriter; |
| |
| import javax.xml.parsers.DocumentBuilderFactory; |
| import javax.xml.transform.OutputKeys; |
| import javax.xml.transform.Transformer; |
| import javax.xml.transform.TransformerFactory; |
| import javax.xml.transform.dom.DOMSource; |
| import javax.xml.transform.stream.StreamResult; |
| |
| import org.apache.xpath.domapi.XPathEvaluatorImpl; |
| import org.w3c.dom.Document; |
| import org.w3c.dom.Node; |
| import org.w3c.dom.xpath.XPathEvaluator; |
| import org.w3c.dom.xpath.XPathNSResolver; |
| import org.w3c.dom.xpath.XPathResult; |
| import org.xml.sax.InputSource; |
| |
| /** |
| * Very basic utility for applying the DOM L3 XPath API (currently in Last Call) |
| * to an xml file and printing information about the execution of the XPath object |
| * and the nodes it finds. |
| * Takes 2 arguments: |
| * (1) an xml filename |
| * (2) an XPath expression to apply to the file |
| * Examples: |
| * java ApplyXPathDOM foo.xml / |
| * java ApplyXPathDOM foo.xml /doc/name[1]/@last |
| * |
| *<p>See also the <a href='http://www.w3.org/TR/2004/NOTE-DOM-Level-3-XPath-20040226'>Document Object Model (DOM) Level 3 XPath Specification</a>.</p> |
| * @see XPathEvaluator |
| * |
| */ |
| public class ApplyXPathDOM |
| { |
| protected String filename = null; |
| protected String xpath = null; |
| |
| /** Process input args and execute the XPath. */ |
| public void doMain(String[] args) |
| throws Exception |
| { |
| filename = args[0]; |
| xpath = args[1]; |
| |
| if ((filename != null) && (filename.length() > 0) |
| && (xpath != null) && (xpath.length() > 0)) |
| { |
| // Tell that we're loading classes and parsing, so the time it |
| // takes to do this doesn't get confused with the time to do |
| // the actual query and serialization. |
| System.out.println("Loading classes, parsing "+filename+", and setting up serializer"); |
| |
| // Set up a DOM tree to query. |
| InputSource in = new InputSource(new FileInputStream(filename)); |
| DocumentBuilderFactory dfactory = DocumentBuilderFactory.newInstance(); |
| dfactory.setNamespaceAware(true); |
| Document doc = dfactory.newDocumentBuilder().parse(in); |
| |
| // Set up an identity transformer to use as serializer. |
| Transformer serializer = TransformerFactory.newInstance().newTransformer(); |
| serializer.setOutputProperty(OutputKeys.OMIT_XML_DECLARATION, "yes"); |
| |
| // Use the DOM L3 XPath API to apply the xpath expression to the doc. |
| System.out.println("Querying DOM using "+xpath); |
| |
| // Create an XPath evaluator and pass in the document. |
| XPathEvaluator evaluator = new XPathEvaluatorImpl(doc); |
| XPathNSResolver resolver = evaluator.createNSResolver(doc); |
| |
| // Evaluate the xpath expression |
| XPathResult result = (XPathResult)evaluator.evaluate(xpath, doc, resolver, XPathResult.UNORDERED_NODE_ITERATOR_TYPE, null); |
| |
| |
| // Serialize the found nodes to System.out. |
| System.out.println("<output>"); |
| |
| Node n; |
| while ((n = result.iterateNext())!= null) |
| { |
| if (isTextNode(n)) { |
| // DOM may have more than one node corresponding to a |
| // single XPath text node. Coalesce all contiguous text nodes |
| // at this level |
| StringBuffer sb = new StringBuffer(n.getNodeValue()); |
| for ( |
| Node nn = n.getNextSibling(); |
| isTextNode(nn); |
| nn = nn.getNextSibling() |
| ) { |
| sb.append(nn.getNodeValue()); |
| } |
| System.out.print(sb); |
| } |
| else { |
| serializer.transform(new DOMSource(n), new StreamResult(new OutputStreamWriter(System.out))); |
| } |
| System.out.println(); |
| } |
| System.out.println("</output>"); |
| } |
| else |
| { |
| System.out.println("Bad input args: " + filename + ", " + xpath); |
| } |
| } |
| |
| /** Decide if the node is text, and so must be handled specially */ |
| static boolean isTextNode(Node n) { |
| if (n == null) |
| return false; |
| short nodeType = n.getNodeType(); |
| return nodeType == Node.CDATA_SECTION_NODE || nodeType == Node.TEXT_NODE; |
| } |
| |
| /** Main method to run from the command line. */ |
| public static void main (String[] args) |
| throws Exception |
| { |
| if (args.length != 2) |
| { |
| System.out.println("java ApplyXPathDOM filename.xml xpath\n" |
| + "Reads filename.xml and applies the xpath; prints the nodelist found."); |
| return; |
| } |
| |
| ApplyXPathDOM app = new ApplyXPathDOM(); |
| app.doMain(args); |
| } |
| |
| } // end of class ApplyXPathDOM |
| |