Java tutorial
/* =============================================================================== * * Part of the InfoGlue Content Management Platform (www.infoglue.org) * * =============================================================================== * * Copyright (C) * * This program is free software; you can redistribute it and/or modify it under * the terms of the GNU General Public License version 2, as published by the * Free Software Foundation. See the file LICENSE.html for more information. * * This program is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY, including the implied warranty of MERCHANTABILITY or FITNESS * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. * * You should have received a copy of the GNU General Public License along with * this program; if not, write to the Free Software Foundation, Inc. / 59 Temple * Place, Suite 330 / Boston, MA 02111-1307 / USA. * * =============================================================================== */ package org.infoglue.cms.util.dom; import java.io.ByteArrayInputStream; import java.io.ByteArrayOutputStream; import java.io.File; import java.io.FileWriter; import java.io.IOException; import java.io.StringWriter; import java.util.HashMap; import java.util.Map; import org.apache.log4j.Logger; import org.dom4j.Document; import org.dom4j.DocumentHelper; import org.dom4j.Element; import org.dom4j.Node; import org.dom4j.io.DOMReader; import org.dom4j.io.OutputFormat; import org.dom4j.io.SAXReader; import org.dom4j.io.XMLWriter; import org.infoglue.cms.exception.SystemException; import org.infoglue.cms.io.FileHelper; import org.xml.sax.InputSource; /** * This class is a utility-class for handling DOM-objects. * * @author Mattias Bogeblad */ public class DOMBuilder { private final static Logger logger = Logger.getLogger(DOMBuilder.class.getName()); /** * This method creates a new Document. */ public Document createDocument() { return DocumentHelper.createDocument(); } /** * This method creates a new Document from an xml-string. */ public Document getDocument(String xml) throws Exception { return getDocument(xml, false); } /** * This method creates a new Document from an xml-string. */ public Document getDocument(String xml, boolean validateExternalDTD) throws Exception { if (xml == null) return null; try { InputSource xmlSource = new InputSource(new ByteArrayInputStream(xml.getBytes("UTF-8"))); SAXReader xmlReader = new SAXReader(validateExternalDTD); if (!validateExternalDTD) xmlReader.setFeature("http://apache.org/xml/features/nonvalidating/load-external-dtd", false); return xmlReader.read(xmlSource); } catch (Exception e) { throw new SystemException(e); } } /** converts a W3C DOM document into a dom4j document */ public Document buildDocment(org.w3c.dom.Document domDocument) { DOMReader xmlReader = new DOMReader(); return xmlReader.read(domDocument); } /** * This method creates a new Document from a file. */ public Document getDocument(File file) throws Exception { if (file == null) return null; Document document = null; try { String xml = FileHelper.readUTF8FromFile(file); document = getDocument(xml); } catch (Exception e) { e.printStackTrace(); } return document; } /** * A helper method to get nodes that has a namespace. */ public Node selectSingleNode(Node contextNode, String xpathExpression, String namespaceName, String namespaceValue) { Map namespaces = new HashMap(); namespaces.put(namespaceName, namespaceValue); org.dom4j.XPath xpath = contextNode.createXPath(xpathExpression); xpath.setNamespaceURIs(namespaces); return xpath.selectSingleNode(contextNode); } /** * This method adds an element with a given name to a given document. */ public Element addElement(Document document, String elementName) { Element newElement = document.addElement(elementName); return newElement; } /** * This method adds an element with a given name to a given parent element. */ public Element addElement(Element element, String elementName) { Element newElement = element.addElement(elementName); return newElement; } /** * This method adds an element to a given parent element. */ public void insertElement(Element element, Element childElement) { element.content().add(childElement); } /** * This method adds a text-element with a given name to a given parent element. */ public Element addTextElement(Element element, String text) { Element newElement = element.addText(text); return newElement; } /** * This method adds a cdata-element with a given name to a given parent element. */ public Element addCDATAElement(Element element, String text) { Element newElement = element.addCDATA(text); return newElement; } /** * This method adds an attribute with a given name and value to a given element. */ public void addAttribute(Element element, String attributeName, String attributeValue) { element.addAttribute(attributeName, attributeValue); } /** * This method writes a document to file. */ public void write(Document document, String fileName) throws Exception { OutputFormat format = OutputFormat.createCompactFormat(); format.setEncoding("UTF-8"); XMLWriter writer = new XMLWriter(new FileWriter(fileName), format); writer.write(document); writer.close(); } /** * This method writes a document to file nicely. */ public void writePretty(Document document, String fileName) throws IOException { OutputFormat format = OutputFormat.createPrettyPrint(); XMLWriter writer = new XMLWriter(new FileWriter(fileName), format); writer.write(document); writer.close(); } /** * This method writes a document to System.out. */ public void writeDebug(Document document) throws Exception { OutputFormat format = OutputFormat.createPrettyPrint(); XMLWriter writer = new XMLWriter(System.out, format); writer.write(document); } public String encodeString(String value, String encoding) throws Exception { String encodedValue = new String(value.getBytes("UTF-8"), "ISO-8859-1"); return encodedValue; } /** * This method writes a element to System.out. */ public void writeDebug(Element element) throws Exception { OutputFormat format = OutputFormat.createPrettyPrint(); XMLWriter writer = new XMLWriter(System.out, format); writer.write(element); } /** * This method gets the xml as a string with the correct encoding. */ private String getEncodedString(Element element) throws Exception { OutputFormat outFormat = OutputFormat.createCompactFormat(); outFormat.setEncoding("UTF-8"); ByteArrayOutputStream bao = new ByteArrayOutputStream(); XMLWriter out = new XMLWriter(bao, outFormat); out.write(element); out.flush(); String s = bao.toString(); logger.info("OUT: " + s); return s; } public String getFormattedDocument(Document doc, String encoding) { return getFormattedDocument(doc, true, false, encoding); } public String getFormattedDocument(Document doc, boolean compact, boolean supressDecl, String encoding) { OutputFormat format = compact ? OutputFormat.createCompactFormat() : OutputFormat.createPrettyPrint(); format.setSuppressDeclaration(supressDecl); format.setEncoding(encoding); format.setExpandEmptyElements(false); StringWriter stringWriter = new StringWriter(); XMLWriter writer = new XMLWriter(stringWriter, format); try { writer.write(doc); } catch (IOException e) { e.printStackTrace(); } return stringWriter.toString(); } }