Java tutorial
/* * Copyright 2001-2005 (C) MetaStuff, Ltd. All Rights Reserved. * * This software is open source. * See the bottom of this file for the licence. */ package org.dom4j.io; import java.util.ArrayList; import java.util.List; import org.dom4j.*; import org.dom4j.dom.DOMAttribute; import org.dom4j.tree.NamespaceStack; /** * <p> * <code>DOMReader</code> navigates a W3C DOM tree and creates a DOM4J tree * from it. * </p> * * @author <a href="mailto:jstrachan@apache.org">James Strachan </a> * @version $Revision: 1.17 $ */ public class DOMReader { /** <code>DocumentFactory</code> used to create new document objects */ private DocumentFactory factory; /** stack of <code>Namespace</code> and <code>QName</code> objects */ private NamespaceStack namespaceStack; public DOMReader() { this.factory = DocumentFactory.getInstance(); this.namespaceStack = new NamespaceStack(factory); } public DOMReader(DocumentFactory factory) { this.factory = factory; this.namespaceStack = new NamespaceStack(factory); } /** * DOCUMENT ME! * * @return the <code>DocumentFactory</code> used to create document * objects */ public DocumentFactory getDocumentFactory() { return factory; } /** * <p> * This sets the <code>DocumentFactory</code> used to create new * documents. This method allows the building of custom DOM4J tree objects * to be implemented easily using a custom derivation of * {@link DocumentFactory} * </p> * * @param docFactory * <code>DocumentFactory</code> used to create DOM4J objects */ public void setDocumentFactory(DocumentFactory docFactory) { this.factory = docFactory; this.namespaceStack.setDocumentFactory(factory); } public Document read(org.w3c.dom.Document domDocument) { if (domDocument instanceof Document) { return (Document) domDocument; } Document document = createDocument(); clearNamespaceStack(); org.w3c.dom.NodeList nodeList = domDocument.getChildNodes(); for (int i = 0, size = nodeList.getLength(); i < size; i++) { readTree(nodeList.item(i), document); } return document; } // Implementation methods protected void readTree(org.w3c.dom.Node node, Branch current) { Element element = null; Document document = null; if (current instanceof Element) { element = (Element) current; } else { document = (Document) current; } switch (node.getNodeType()) { case org.w3c.dom.Node.ELEMENT_NODE: readElement(node, current); break; case org.w3c.dom.Node.PROCESSING_INSTRUCTION_NODE: if (current instanceof Element) { Element currentEl = (Element) current; currentEl.addProcessingInstruction(node.getNodeName(), node.getNodeValue()); } else { Document currentDoc = (Document) current; currentDoc.addProcessingInstruction(node.getNodeName(), node.getNodeValue()); } break; case org.w3c.dom.Node.COMMENT_NODE: if (current instanceof Element) { ((Element) current).addComment(node.getNodeValue()); } else { ((Document) current).addComment(node.getNodeValue()); } break; case org.w3c.dom.Node.DOCUMENT_TYPE_NODE: org.w3c.dom.DocumentType domDocType = (org.w3c.dom.DocumentType) node; document.addDocType(domDocType.getName(), domDocType.getPublicId(), domDocType.getSystemId()); break; case org.w3c.dom.Node.TEXT_NODE: element.addText(node.getNodeValue()); break; case org.w3c.dom.Node.CDATA_SECTION_NODE: element.addCDATA(node.getNodeValue()); break; case org.w3c.dom.Node.ENTITY_REFERENCE_NODE: // is there a better way to get the value of an entity? org.w3c.dom.Node firstChild = node.getFirstChild(); if (firstChild != null) { element.addEntity(node.getNodeName(), firstChild.getNodeValue()); } else { element.addEntity(node.getNodeName(), ""); } break; case org.w3c.dom.Node.ENTITY_NODE: element.addEntity(node.getNodeName(), node.getNodeValue()); break; default: System.out.println("WARNING: Unknown DOM node type: " + node.getNodeType()); } } protected void readElement(org.w3c.dom.Node node, Branch current) { int previouslyDeclaredNamespaces = namespaceStack.size(); String namespaceUri = node.getNamespaceURI(); String elementPrefix = node.getPrefix(); if (elementPrefix == null) { elementPrefix = ""; } org.w3c.dom.NamedNodeMap attributeList = node.getAttributes(); if ((attributeList != null) && (namespaceUri == null)) { // test if we have an "xmlns" attribute org.w3c.dom.Node attribute = attributeList.getNamedItem("xmlns"); if (attribute != null) { namespaceUri = attribute.getNodeValue(); elementPrefix = ""; } } QName qName = namespaceStack.getQName(namespaceUri, node.getLocalName(), node.getNodeName()); Element element = current.addElement(qName); if (attributeList != null) { int size = attributeList.getLength(); List<org.w3c.dom.Node> attributes = new ArrayList<org.w3c.dom.Node>(size); for (int i = 0; i < size; i++) { org.w3c.dom.Node attribute = attributeList.item(i); // Define all namespaces first then process attributes later String name = attribute.getNodeName(); if (name.startsWith("xmlns")) { String prefix = getPrefix(name); String uri = attribute.getNodeValue(); Namespace namespace = namespaceStack.addNamespace(prefix, uri); element.add(namespace); } else { attributes.add(attribute); } } // now add the attributes, the namespaces should be available size = attributes.size(); for (int i = 0; i < size; i++) { org.w3c.dom.Node attribute = (org.w3c.dom.Node) attributes.get(i); QName attributeQName = namespaceStack.getQName(attribute.getNamespaceURI(), attribute.getLocalName(), attribute.getNodeName()); element.addAttribute(attributeQName, attribute.getNodeValue()); } } // Recurse on child nodes org.w3c.dom.NodeList children = node.getChildNodes(); for (int i = 0, size = children.getLength(); i < size; i++) { org.w3c.dom.Node child = children.item(i); readTree(child, element); } // pop namespaces from the stack while (namespaceStack.size() > previouslyDeclaredNamespaces) { namespaceStack.pop(); } } protected Namespace getNamespace(String prefix, String uri) { return getDocumentFactory().createNamespace(prefix, uri); } protected Document createDocument() { return getDocumentFactory().createDocument(); } protected void clearNamespaceStack() { namespaceStack.clear(); if (!namespaceStack.contains(Namespace.XML_NAMESPACE)) { namespaceStack.push(Namespace.XML_NAMESPACE); } } private String getPrefix(String xmlnsDecl) { int index = xmlnsDecl.indexOf(':', 5); if (index != -1) { return xmlnsDecl.substring(index + 1); } else { return ""; } } } /* * Redistribution and use of this software and associated documentation * ("Software"), with or without modification, are permitted provided that the * following conditions are met: * * 1. Redistributions of source code must retain copyright statements and * notices. Redistributions must also contain a copy of this document. * * 2. Redistributions in binary form must reproduce the above copyright notice, * this list of conditions and the following disclaimer in the documentation * and/or other materials provided with the distribution. * * 3. The name "DOM4J" must not be used to endorse or promote products derived * from this Software without prior written permission of MetaStuff, Ltd. For * written permission, please contact dom4j-info@metastuff.com. * * 4. Products derived from this Software may not be called "DOM4J" nor may * "DOM4J" appear in their names without prior written permission of MetaStuff, * Ltd. DOM4J is a registered trademark of MetaStuff, Ltd. * * 5. Due credit should be given to the DOM4J Project - http://www.dom4j.org * * THIS SOFTWARE IS PROVIDED BY METASTUFF, LTD. AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL METASTUFF, LTD. OR ITS CONTRIBUTORS BE * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. * * Copyright 2001-2005 (C) MetaStuff, Ltd. All Rights Reserved. */