Java tutorial
/******************************************************************************* * Copyright (c) 2009-2013 CWI * 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: * * Tijs van der Storm - Tijs.van.der.Storm@cwi.nl * * Mark Hills - Mark.Hills@cwi.nl (CWI) *******************************************************************************/ package org.rascalmpl.library.lang.xml; import java.io.CharArrayReader; import java.io.IOException; import java.io.StringWriter; import java.io.Writer; import org.jdom2.Attribute; import org.jdom2.CDATA; import org.jdom2.Comment; import org.jdom2.Content; import org.jdom2.Document; import org.jdom2.Element; import org.jdom2.EntityRef; import org.jdom2.JDOMException; import org.jdom2.Namespace; import org.jdom2.ProcessingInstruction; import org.jdom2.Text; import org.jdom2.input.SAXBuilder; import org.jdom2.output.Format; import org.jdom2.output.XMLOutputter; import org.rascalmpl.value.IConstructor; import org.rascalmpl.value.IInteger; import org.rascalmpl.value.IList; import org.rascalmpl.value.IListWriter; import org.rascalmpl.value.IString; import org.rascalmpl.value.IValue; import org.rascalmpl.value.IValueFactory; public class DOM { private final IValueFactory vf; public DOM(IValueFactory vf) { this.vf = vf; } private static class Skip extends Exception { private static final long serialVersionUID = -6330585199877497106L; } public IConstructor parseXMLDOMTrim(IString str) throws IOException, JDOMException { return parseXMLDOM(str, true); } public IConstructor parseXMLDOM(IString str) throws IOException, JDOMException { return parseXMLDOM(str, false); } public IString xmlRaw(IConstructor node) throws IOException { return xmlToString(node, Format.getRawFormat()); } public IString xmlPretty(IConstructor node) throws IOException { return xmlToString(node, Format.getPrettyFormat()); } public IString xmlCompact(IConstructor node) throws IOException { return xmlToString(node, Format.getCompactFormat()); } private IConstructor parseXMLDOM(IString str, boolean trim) throws JDOMException, IOException { SAXBuilder builder = new SAXBuilder(); CharArrayReader reader = new CharArrayReader(str.getValue().toCharArray()); Document doc = builder.build(reader); return convertDocument(doc, trim); } private IString xmlToString(IConstructor node, Format format) throws IOException { StringWriter writer = new StringWriter(); writeXML(writer, nodeToDocument(node), format); return vf.string(writer.toString()); } private void writeXML(Writer writer, Document document, Format format) throws IOException { XMLOutputter outputter = new XMLOutputter(format); outputter.output(document, writer); writer.close(); } private Document nodeToDocument(IConstructor node) { if (node.getType() != Factory.Node) { wellformednessError(); } if (node.getConstructorType() != Factory.Node_document && node.getConstructorType() != Factory.Node_element) { wellformednessError(); } if (node.getConstructorType() == Factory.Node_document) { return new Document(nodeToElement((IConstructor) node.get(0))); } return new Document(nodeToElement(node)); } private Element nodeToElement(IConstructor elt) { IConstructor ns = (IConstructor) elt.get(0); IString name = (IString) elt.get(1); IList kids = (IList) elt.get(2); Element e = new Element(name.getValue(), namespaceToNamespace(ns)); for (IValue k : kids) { IConstructor n = (IConstructor) k; if (n.getConstructorType() == Factory.Node_attribute) { e.setAttribute(nodeToAttribute(n)); } else { e.addContent(nodeToContent(n)); } } return e; } private Content nodeToContent(IConstructor n) { if (n.getConstructorType() == Factory.Node_element) { return nodeToElement(n); } if (n.getConstructorType() == Factory.Node_pi) { IString target = (IString) n.get(0); IString data = (IString) n.get(1); return new ProcessingInstruction(target.getValue(), data.getValue()); } if (n.getConstructorType() == Factory.Node_charRef) { IInteger code = (IInteger) n.get(0); int c = java.lang.Integer.parseInt(code.getStringRepresentation()); return new Text(new java.lang.String(Character.toChars(c))); } if (n.getConstructorType() == Factory.Node_entityRef) { return new EntityRef(((IString) n.get(0)).getValue()); } java.lang.String text = ((IString) n.get(0)).getValue(); if (n.getConstructorType() == Factory.Node_cdata) { return new CDATA(text); } if (n.getConstructorType() == Factory.Node_charData) { return new Text(text); } if (n.getConstructorType() == Factory.Node_comment) { return new Comment(text); } wellformednessError(); return null; } private Attribute nodeToAttribute(IConstructor n) { IConstructor ns = (IConstructor) n.get(0); IString name = (IString) n.get(1); IString data = (IString) n.get(2); return new Attribute(name.getValue(), data.getValue(), namespaceToNamespace(ns)); } private Namespace namespaceToNamespace(IConstructor ns) { if (ns.getConstructorType() == Factory.Namespace_none) { return Namespace.NO_NAMESPACE; } IString prefix = (IString) ns.get(0); IString uri = (IString) ns.get(1); return Namespace.getNamespace(prefix.getValue(), uri.getValue()); } private void wellformednessError() { throw new RuntimeException("Nonwellformed XML node (TODO: make Rascal runtime exception)"); } private IConstructor convertDocument(Document doc, boolean trim) { IConstructor root = convertElement(doc.getRootElement(), trim); return vf.constructor(Factory.Node_document, root); } private IConstructor convertElement(Element e, boolean trim) { IListWriter kids = vf.listWriter(Factory.Node); for (Object o : e.getAttributes()) { Attribute attr = (Attribute) o; IString key = vf.string(attr.getName()); IString val = vf.string(attr.getValue()); kids.insert(vf.constructor(Factory.Node_attribute, convertNamespace(attr.getNamespace()), key, val)); } int len = e.getContentSize(); for (int i = 0; i < len; i++) { try { kids.append(convertContent(e.getContent(i), trim)); } catch (Skip c) { // Ugh, terrible, but I'm in hurry continue; } } IString name = vf.string(e.getName()); return vf.constructor(Factory.Node_element, convertNamespace(e.getNamespace()), name, kids.done()); } private IConstructor convertNamespace(Namespace ns) { if (ns == Namespace.NO_NAMESPACE) { return vf.constructor(Factory.Namespace_none); } IString prefix = vf.string(ns.getPrefix()); IString uri = vf.string(ns.getURI()); IConstructor nscon = vf.constructor(Factory.Namespace_namespace, prefix, uri); return nscon; } private IConstructor convertContent(Content content, boolean trim) throws Skip { if (content instanceof Element) { return convertElement((Element) content, trim); } if (content instanceof CDATA) { // CDATA first (is subtype of Text) CDATA cdata = (CDATA) content; return vf.constructor(Factory.Node_cdata, getString(trim, cdata)); } if (content instanceof Text) { Text text = (Text) content; return vf.constructor(Factory.Node_charData, getString(trim, text)); } if (content instanceof Comment) { Comment comment = (Comment) content; IString data = vf.string(comment.getText()); return vf.constructor(Factory.Node_comment, data); } if (content instanceof ProcessingInstruction) { ProcessingInstruction pi = (ProcessingInstruction) content; IString data = vf.string(pi.getData()); return vf.constructor(Factory.Node_pi, data); } if (content instanceof EntityRef) { EntityRef er = (EntityRef) content; IString data = vf.string(er.getName()); return vf.constructor(Factory.Node_entityRef, data); } throw new AssertionError("cannot convert JDOM content type " + content.getClass()); } private IString getString(boolean trim, Text text) throws Skip { if (trim) { java.lang.String s = text.getTextTrim(); if ("".equals(s)) { throw new Skip(); } return vf.string(s); } return vf.string(text.getText()); } }