Java tutorial
/******************************************************************************* * Copyright (c) 2010-2014 SAP AG and others. * All rights reserved. This program and the accompanying materials * are made available under the terms of the Eclipse Public License v1.0 * which accompanies this distribution, and is available at * http://www.eclipse.org/legal/epl-v10.html * * Contributors: * SAP AG - initial API and implementation *******************************************************************************/ package org.eclipse.skalli.commons; import java.io.ByteArrayInputStream; import java.io.ByteArrayOutputStream; import java.io.File; import java.io.FileNotFoundException; import java.io.FileOutputStream; import java.io.IOException; import java.io.InputStream; import java.io.StringReader; import java.io.StringWriter; import java.net.URL; import javax.xml.parsers.DocumentBuilder; import javax.xml.parsers.DocumentBuilderFactory; import javax.xml.parsers.ParserConfigurationException; import javax.xml.transform.OutputKeys; 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.commons.io.IOUtils; import org.w3c.dom.Document; import org.xml.sax.InputSource; import org.xml.sax.SAXException; public class XMLUtils { /** Namespace prefix (<tt>{@value}</tt>) */ public static final String XMLNS = "xmlns"; //$NON-NLS-1$ /** XML Schema namespace prefix (<tt>{@value}</tt>) */ public static final String XMLNS_XSI = "xmlns:xsi"; //$NON-NLS-1$ /** XML Schema Instance namespace (<tt>{@value}</tt>) */ public static final String XSI_INSTANCE_NS = "http://www.w3.org/2001/XMLSchema-instance"; //$NON-NLS-1$ /** XML Schema Location attribute (<tt>{@value}</tt>) */ public static final String XSI_SCHEMA_LOCATION = "xsi:schemaLocation"; //$NON-NLS-1$ // no instances, please! private XMLUtils() { } /** * Returns a new, empty XML document. * @throws ParserConfigurationException a serious serious configuration error occured. */ public static Document newDocument() throws ParserConfigurationException { return getDocumentBuilder().newDocument(); } /** * Reads and parses an XML document from a given file. * * @param file the file to read and parse. * @return an XML document parsed from the given file. * * @throws SAXException if a parsing error occurd. * @throws IOException if an i/o error occured. * @throws ParserConfigurationException a serious serious configuration error occured. */ public static Document documentFromFile(File file) throws SAXException, IOException, ParserConfigurationException { DocumentBuilder docBuilder = getDocumentBuilder(); Document doc = docBuilder.parse(file); return doc; } /** * Reads and parses an XML document from a resource file loaded with * the bundle classloader of the given class. * * @param c the class. * @param filename the path and filename of the requested resource relative to the bundle root * of the bundle containg the given class. * * @return an XML document parsed from the given file, or <code>null</code> if the requested * resource was not found. * * @throws SAXException if a parsing error occurd. * @throws IOException if an i/o error occured. * @throws ParserConfigurationException a serious serious configuration error occured. */ public static Document documentFromResource(Class<?> c, String filename) throws SAXException, IOException, ParserConfigurationException { URL urlBefore = c.getResource(filename); if (urlBefore == null) { return null; } InputStream isBefore = null; try { isBefore = urlBefore.openStream(); DocumentBuilder docBuilder = getDocumentBuilder(); Document doc = docBuilder.parse(isBefore); return doc; } finally { if (isBefore != null) { isBefore.close(); } } } /** * Reads and parses an XML document from a given stream. * * @param in the stream to read and parse. * @return an XML document parsed from the given stream. * * @throws SAXException if a parsing error occurd. * @throws IOException if an i/o error occured. * @throws ParserConfigurationException a serious serious configuration error occured. */ public static Document documentFromStream(InputStream in) throws SAXException, IOException, ParserConfigurationException { DocumentBuilder docBuilder = getDocumentBuilder(); Document doc = docBuilder.parse(in); return doc; } /** * Reads and parses an XML document from a given string. * * @param xml the string to read and parse. * @return an XML document parsed from the given string. * * @throws SAXException if a parsing error occurd. * @throws IOException if an i/o error occured. * @throws ParserConfigurationException a serious serious configuration error occured. */ public static Document documentFromString(String xml) throws SAXException, IOException, ParserConfigurationException { DocumentBuilder docBuilder = getDocumentBuilder(); Document doc = docBuilder.parse(new InputSource(new StringReader(xml))); return doc; } /** * Transforms the given XML document into its textual representation. * * @param doc the document to transform. * @return the XML document transformed to a string. * * @throws TransformerException if the transformation failed. */ public static String documentToString(Document doc) throws TransformerException { StreamResult result = new StreamResult(new StringWriter()); transform(doc, result); String xmlString = result.getWriter().toString(); return xmlString; } /** * Transforms the given XML document into its textual representation and * writes the result to a file. * * @param doc the document to transform. * @param file the target file. * * @throws TransformerException if the transformation failed. * @throws FileNotFoundException if a folder with the same name exists, * or the file cannot be created or opened. */ public static void documentToFile(Document doc, File file) throws TransformerException, FileNotFoundException { FileOutputStream fos = new FileOutputStream(file); try { StreamResult result = new StreamResult(fos); transform(doc, result); } finally { IOUtils.closeQuietly(fos); } } /** * Transforms the given XML document into its textual representation and * provides the result as input stream. * * @param doc the document to transform. * @return an input stream from which the textual representation of the XML document can be read. * * @throws TransformerException if the transformation failed. */ public static InputStream documentToStream(Document doc) throws TransformerException { ByteArrayOutputStream os = new ByteArrayOutputStream(); try { StreamResult result = new StreamResult(os); transform(doc, result); return new ByteArrayInputStream(os.toByteArray()); } finally { IOUtils.closeQuietly(os); } } private static DocumentBuilder getDocumentBuilder() throws ParserConfigurationException { DocumentBuilderFactory docFactory = DocumentBuilderFactory.newInstance(); DocumentBuilder docBuilder = docFactory.newDocumentBuilder(); return docBuilder; } private static void transform(Document doc, StreamResult result) throws TransformerException { DOMSource source = new DOMSource(doc); Transformer transformer = TransformerFactory.newInstance().newTransformer(); transformer.setOutputProperty(OutputKeys.INDENT, "yes"); //$NON-NLS-1$ transformer.transform(source, result); } }