| /** |
| * 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.hadoop.vaidya.util; |
| |
| import java.io.IOException; |
| import java.io.File; |
| import java.io.InputStream; |
| import javax.xml.parsers.DocumentBuilderFactory; |
| import javax.xml.parsers.ParserConfigurationException; |
| import javax.xml.parsers.DocumentBuilder; |
| import javax.xml.transform.TransformerConfigurationException; |
| import javax.xml.transform.TransformerException; |
| import javax.xml.transform.Source; |
| import javax.xml.transform.dom.DOMSource; |
| import javax.xml.transform.Result; |
| import javax.xml.transform.stream.StreamResult; |
| import javax.xml.transform.Transformer; |
| import javax.xml.transform.TransformerFactory; |
| |
| import org.xml.sax.SAXParseException; |
| import org.xml.sax.SAXException; |
| |
| import org.w3c.dom.Document; |
| import org.w3c.dom.Element; |
| import org.w3c.dom.NamedNodeMap; |
| import org.w3c.dom.Node; |
| import org.w3c.dom.NodeList; |
| |
| |
| /** |
| * Sample Utility class to work with DOM document |
| */ |
| public class XMLUtils { |
| |
| /** Prints the specified node, then prints all of its children. */ |
| |
| public static void printDOM(Node node) { |
| |
| int type = node.getNodeType(); |
| |
| switch (type) { |
| |
| // print the document element |
| case Node.DOCUMENT_NODE: { |
| System.out.print("<?xml version=\"1.0\" ?>"); |
| printDOM(((Document)node).getDocumentElement()); |
| break; |
| } |
| |
| // print element with attributes |
| case Node.ELEMENT_NODE: { |
| System.out.println(); |
| System.out.print("<"); |
| System.out.print(node.getNodeName()); |
| NamedNodeMap attrs = node.getAttributes(); |
| for (int i = 0; i < attrs.getLength(); i++) { |
| Node attr = attrs.item(i); |
| System.out.print(" " + attr.getNodeName().trim() + |
| "=\"" + attr.getNodeValue().trim() + |
| "\""); |
| } |
| System.out.print(">"); |
| NodeList children = node.getChildNodes(); |
| |
| if (children != null) { |
| int len = children.getLength(); |
| for (int i = 0; i < len; i++) |
| printDOM(children.item(i)); |
| } |
| break; |
| } |
| |
| // handle entity reference nodes |
| |
| case Node.ENTITY_REFERENCE_NODE: { |
| System.out.print("&"); |
| System.out.print(node.getNodeName().trim()); |
| System.out.print(";"); |
| break; |
| } |
| |
| // print cdata sections |
| case Node.CDATA_SECTION_NODE: { |
| System.out.print("<![CDATA["); |
| System.out.print(node.getNodeValue().trim()); |
| System.out.print("]]>"); |
| break; |
| } |
| |
| // print text |
| case Node.TEXT_NODE: { |
| System.out.println(); |
| System.out.print(node.getNodeValue().trim()); |
| break; |
| } |
| |
| // print processing instruction |
| |
| case Node.PROCESSING_INSTRUCTION_NODE: { |
| System.out.print("<?"); |
| System.out.print(node.getNodeName().trim()); |
| String data = node.getNodeValue().trim(); { |
| System.out.print(" "); |
| System.out.print(data); |
| } |
| System.out.print("?>"); |
| break; |
| } |
| } |
| |
| if (type == Node.ELEMENT_NODE) { |
| System.out.println(); |
| System.out.print("</"); |
| System.out.print(node.getNodeName().trim()); |
| System.out.print('>'); |
| } |
| } |
| |
| /* |
| * Get the value of the first (or only) element given its node name |
| */ |
| public static String getElementValue(String elementName, Element element) throws Exception { |
| String value = null; |
| NodeList childNodes = element.getElementsByTagName(elementName); |
| Element cn = (Element)childNodes.item(0); |
| value = cn.getFirstChild().getNodeValue().trim(); |
| //value = childNodes.item(0).getNodeValue().trim(); |
| if (value == null) { |
| throw new Exception ("No element found with given name:"+elementName); |
| } |
| return value; |
| } |
| |
| /** |
| * Parse the XML file and create Document |
| * @param fileName |
| * @return Document |
| */ |
| public static Document parse(InputStream fs) { |
| Document document = null; |
| // Initiate DocumentBuilderFactory |
| DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance(); |
| |
| // To get a validating parser |
| factory.setValidating(false); |
| |
| // To get one that understands namespaces |
| factory.setNamespaceAware(true); |
| try { |
| // Get DocumentBuilder |
| DocumentBuilder builder = factory.newDocumentBuilder(); |
| |
| // Parse and load into memory the Document |
| //document = builder.parse( new File(fileName)); |
| document = builder.parse(fs); |
| return document; |
| } catch (SAXParseException spe) { |
| // Error generated by the parser |
| System.err.println("\n** Parsing error , line " + spe.getLineNumber() |
| + ", uri " + spe.getSystemId()); |
| System.err.println(" " + spe.getMessage() ); |
| // Use the contained exception, if any |
| Exception x = spe; |
| if (spe.getException() != null) |
| x = spe.getException(); |
| x.printStackTrace(); |
| } catch (SAXException sxe) { |
| // Error generated during parsing |
| Exception x = sxe; |
| if (sxe.getException() != null) |
| x = sxe.getException(); |
| x.printStackTrace(); |
| } catch (ParserConfigurationException pce) { |
| // Parser with specified options can't be built |
| pce.printStackTrace(); |
| } catch (IOException ioe) { |
| // I/O error |
| ioe.printStackTrace(); |
| } |
| |
| return null; |
| } |
| |
| /** |
| * This method writes a DOM document to a file |
| * @param filename |
| * @param document |
| */ |
| public static void writeXmlToFile(String filename, Document document) { |
| try { |
| // Prepare the DOM document for writing |
| Source source = new DOMSource(document); |
| |
| // Prepare the output file |
| File file = new File(filename); |
| Result result = new StreamResult(file); |
| |
| // Write the DOM document to the file |
| // Get Transformer |
| Transformer xformer = TransformerFactory.newInstance().newTransformer(); |
| |
| // Write to a file |
| xformer.transform(source, result); |
| |
| } catch (TransformerConfigurationException e) { |
| System.err.println("TransformerConfigurationException: " + e); |
| } catch (TransformerException e) { |
| System.err.println("TransformerException: " + e); |
| } |
| } |
| |
| /** |
| * Count Elements in Document by Tag Name |
| * @param tag |
| * @param document |
| * @return number elements by Tag Name |
| */ |
| public static int countByTagName(String tag, Document document){ |
| NodeList list = document.getElementsByTagName(tag); |
| return list.getLength(); |
| } |
| } |