/***************************************************************************** * * 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.padaf.xmpbox.parser; import java.io.File; import java.io.IOException; import java.io.InputStream; import java.io.OutputStream; import java.io.StringWriter; import javax.xml.parsers.DocumentBuilder; import javax.xml.parsers.DocumentBuilderFactory; import javax.xml.transform.OutputKeys; import javax.xml.transform.Result; import javax.xml.transform.Transformer; import javax.xml.transform.TransformerException; import javax.xml.transform.TransformerFactory; import javax.xml.transform.dom.DOMSource; import javax.xml.transform.stream.StreamResult; import org.apache.padaf.xmpbox.type.Elementable; import org.w3c.dom.Document; import org.w3c.dom.Element; import org.w3c.dom.Node; import org.w3c.dom.NodeList; import org.w3c.dom.Text; import org.xml.sax.InputSource; /** * This class with handle some simple XML operations. * * @author <a href="mailto:ben@benlitchfield.com">Ben Litchfield</a> * @author <a href="mailto:chris@oezbek.net">Christopher Oezbek</a> * * @version $Revision: 1.2 $ */ public final class XMLUtil { /** * Utility class, should not be instantiated. * */ private XMLUtil() { } /** * This will parse an XML stream and create a DOM document. * * @param is * The stream to get the XML from. * @return The DOM document. * @throws IOException * It there is an error creating the dom. */ public static Document parse(InputStream is) throws IOException { try { DocumentBuilderFactory builderFactory = DocumentBuilderFactory .newInstance(); DocumentBuilder builder = builderFactory.newDocumentBuilder(); return builder.parse(is); } catch (Exception e) { IOException thrown = new IOException(e.getMessage()); throw thrown; } } /** * This will parse an InputSource and create a DOM document. * * @param is * The stream to get the XML from. * @return The DOM document. * @throws IOException * It there is an error creating the dom. */ public static Document parse(InputSource is) throws IOException { try { DocumentBuilderFactory builderFactory = DocumentBuilderFactory .newInstance(); DocumentBuilder builder = builderFactory.newDocumentBuilder(); return builder.parse(is); } catch (Exception e) { IOException thrown = new IOException(e.getMessage()); throw thrown; } } /** * This will parse an XML stream and create a DOM document. * * @param fileName * The file to get the XML from. * @return The DOM document. * @throws IOException * It there is an error creating the dom. */ public static Document parse(String fileName) throws IOException { try { DocumentBuilderFactory builderFactory = DocumentBuilderFactory .newInstance(); DocumentBuilder builder = builderFactory.newDocumentBuilder(); return builder.parse(fileName); } catch (Exception e) { IOException thrown = new IOException(e.getMessage()); throw thrown; } } /** * Create a new blank XML document. * * @return The new blank XML document. * * @throws IOException * If there is an error creating the XML document. */ public static Document newDocument() throws IOException { try { DocumentBuilderFactory builderFactory = DocumentBuilderFactory .newInstance(); DocumentBuilder builder = builderFactory.newDocumentBuilder(); return builder.newDocument(); } catch (Exception e) { IOException thrown = new IOException(e.getMessage()); throw thrown; } } /** * Get the first instance of an element by name. * * @param parent * The parent to get the element from. * @param elementName * The name of the element to look for. * @return The element or null if it is not found. */ public static Element getElement(Element parent, String elementName) { Element retval = null; NodeList children = parent.getElementsByTagName(elementName); if (children.getLength() > 0) { retval = (Element) children.item(0); } return retval; } /** * Get the integer value of a subnode. * * @param parent * The parent element that holds the values. * @param nodeName * The name of the node that holds the integer value. * * @return The integer value of the node. */ public static Integer getIntValue(Element parent, String nodeName) { String intVal = XMLUtil.getStringValue(XMLUtil.getElement(parent, nodeName)); if (intVal != null) { return Integer.valueOf(intVal); } else { return null; } } /** * Set the integer value of an element. * * @param parent * The parent element that will hold this subelement. * @param nodeName * The name of the subelement. * @param intValue * The value to set. */ public static void setIntValue(Element parent, String nodeName, Integer intValue) { Element currentValue = getElement(parent, nodeName); if (intValue == null) { if (currentValue != null) { parent.removeChild(currentValue); } // else it doesn't exist so we don't need to remove it. } else { if (currentValue == null) { currentValue = parent.getOwnerDocument() .createElement(nodeName); parent.appendChild(currentValue); } XMLUtil.setStringValue(currentValue, intValue.toString()); } } /** * Get the value of a subnode. * * @param parent * The parent element that holds the values. * @param nodeName * The name of the node that holds the value. * * @return The value of the sub node. */ public static String getStringValue(Element parent, String nodeName) { return XMLUtil.getStringValue(XMLUtil.getElement(parent, nodeName)); } /** * Set the value of an element. * * @param parent * The parent element that will hold this subelement. * @param nodeName * The name of the subelement. * @param nodeValue * The value to set. */ public static void setStringValue(Element parent, String nodeName, String nodeValue) { Element currentValue = getElement(parent, nodeName); if (nodeValue == null) { if (currentValue != null) { parent.removeChild(currentValue); } // else it doesn't exist so we don't need to remove it. } else { if (currentValue == null) { currentValue = parent.getOwnerDocument() .createElement(nodeName); parent.appendChild(currentValue); } XMLUtil.setStringValue(currentValue, nodeValue); } } /** * This will get the text value of an element. * * @param node * The node to get the text value for. * @return The text of the node. */ public static String getStringValue(Element node) { String retval = ""; NodeList children = node.getChildNodes(); for (int i = 0; i < children.getLength(); i++) { Node next = children.item(i); if (next instanceof Text) { retval = next.getNodeValue(); } } return retval; } /** * This will set the text value of an element. * * @param node * The node to get the text value for. * @param value * The new value to set the node to. */ public static void setStringValue(Element node, String value) { NodeList children = node.getChildNodes(); for (int i = 0; i < children.getLength(); i++) { Node next = children.item(i); if (next instanceof Text) { node.removeChild(next); } } node.appendChild(node.getOwnerDocument().createTextNode(value)); } /** * Set an XML element document. * * @param parent * The parent document to set the value in. * @param name * The name of the XML element to set. * @param node * The node to set or clear. */ public static void setElementableValue(Element parent, String name, Elementable node) { NodeList nodes = parent.getElementsByTagName(name); if (node == null) { for (int i = 0; i < nodes.getLength(); i++) { parent.removeChild(nodes.item(i)); } } else { if (nodes.getLength() == 0) { if (parent.hasChildNodes()) { Node firstChild = parent.getChildNodes().item(0); parent.insertBefore(node.getElement(), firstChild); } else { parent.appendChild(node.getElement()); } } else { Node oldNode = nodes.item(0); parent.replaceChild(node.getElement(), oldNode); } } } /** * Save the XML document to a file. * * @param doc * The XML document to save. * @param file * The file to save the document to. * @param encoding * The encoding to save the file as. * * @throws TransformerException * If there is an error while saving the XML. */ public static void save(Document doc, String file, String encoding) throws TransformerException { Transformer transformer = TransformerFactory.newInstance() .newTransformer(); transformer.setOutputProperty(OutputKeys.INDENT, "yes"); transformer.setOutputProperty(OutputKeys.ENCODING, encoding); transformer.setOutputProperty(OutputKeys.OMIT_XML_DECLARATION, "yes"); // initialize StreamResult with File object to save to file Result result = new StreamResult(new File(file)); DOMSource source = new DOMSource(doc); transformer.transform(source, result); } /** * Save the XML document to an output stream. * * @param doc * The XML document to save. * @param outStream * The stream to save the document to. * @param encoding * The encoding to save the file as. * * @throws TransformerException * If there is an error while saving the XML. */ public static void save(Node doc, OutputStream outStream, String encoding) throws TransformerException { Transformer transformer = TransformerFactory.newInstance() .newTransformer(); transformer.setOutputProperty(OutputKeys.INDENT, "yes"); transformer.setOutputProperty(OutputKeys.ENCODING, encoding); transformer.setOutputProperty(OutputKeys.OMIT_XML_DECLARATION, "yes"); // initialize StreamResult with File object to save to file Result result = new StreamResult(outStream); DOMSource source = new DOMSource(doc); transformer.transform(source, result); } /** * Convert the document to an array of bytes. * * @param doc * The XML document. * @param encoding * The encoding of the output data. * * @return The XML document as an array of bytes. * * @throws TransformerException * If there is an error transforming to text. */ public static byte[] asByteArray(Document doc, String encoding) throws TransformerException { Transformer transformer = TransformerFactory.newInstance() .newTransformer(); transformer.setOutputProperty(OutputKeys.INDENT, "yes"); transformer.setOutputProperty(OutputKeys.ENCODING, encoding); transformer.setOutputProperty(OutputKeys.OMIT_XML_DECLARATION, "yes"); StringWriter writer = new StringWriter(); Result result = new StreamResult(writer); DOMSource source = new DOMSource(doc); transformer.transform(source, result); return writer.getBuffer().toString().getBytes(); } }