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.tree; import org.dom4j.*; import java.util.ArrayList; import java.util.Collections; import java.util.Iterator; import java.util.List; /** * <p> * <code>DefaultElement</code> is the default DOM4J default implementation of * an XML element. * </p> * * @author <a href="mailto:jstrachan@apache.org">James Strachan </a> * @version $Revision: 1.59 $ */ public class DefaultElement extends AbstractElement { /** The <code>DocumentFactory</code> instance used by default */ private static final transient DocumentFactory DOCUMENT_FACTORY = DocumentFactory.getInstance(); /** The <code>QName</code> for this element */ private QName qname; /** * Stores the parent branch of this node which is either a Document if this * element is the root element in a document, or another Element if it is a * child of the root document, or null if it has not been added to a * document yet. */ private Branch parentBranch; /** * Stores null for no content, a Node for a single content node or a List * for multiple content nodes. The List will be lazily constructed when * required. */ private Object content; /** Lazily constructes list of attributes */ private Object attributes; public DefaultElement(String name) { this.qname = DOCUMENT_FACTORY.createQName(name); } public DefaultElement(QName qname) { this.qname = qname; } public DefaultElement(QName qname, int attributeCount) { this.qname = qname; if (attributeCount > 1) { this.attributes = new ArrayList(attributeCount); } } public DefaultElement(String name, Namespace namespace) { this.qname = DOCUMENT_FACTORY.createQName(name, namespace); } public Element getParent() { Element result = null; if (parentBranch instanceof Element) { result = (Element) parentBranch; } return result; } public void setParent(Element parent) { if (parentBranch instanceof Element || (parent != null)) { parentBranch = parent; } } public Document getDocument() { if (parentBranch instanceof Document) { return (Document) parentBranch; } else if (parentBranch instanceof Element) { Element parent = (Element) parentBranch; return parent.getDocument(); } return null; } public void setDocument(Document document) { if (parentBranch instanceof Document || (document != null)) { parentBranch = document; } } public boolean supportsParent() { return true; } public QName getQName() { return qname; } public void setQName(QName name) { this.qname = name; } public String getText() { final Object contentShadow = content; if (contentShadow instanceof List) { return super.getText(); } else { if (contentShadow != null) { return getContentAsText(contentShadow); } else { return ""; } } } public String getStringValue() { final Object contentShadow = content; if (contentShadow instanceof List) { List<Node> list = (List<Node>) contentShadow; int size = list.size(); if (size > 0) { if (size == 1) { // optimised to avoid StringBuffer creation return getContentAsStringValue(list.get(0)); } else { StringBuilder buffer = new StringBuilder(); for (Node node : list) { String string = getContentAsStringValue(node); if (string.length() > 0) { if (USE_STRINGVALUE_SEPARATOR) { if (buffer.length() > 0) { buffer.append(' '); } } buffer.append(string); } } return buffer.toString(); } } } else { if (contentShadow != null) { return getContentAsStringValue(contentShadow); } } return ""; } public Object clone() { DefaultElement answer = (DefaultElement) super.clone(); if (answer != this) { answer.content = null; answer.attributes = null; answer.appendAttributes(this); answer.appendContent(this); } return answer; } public Namespace getNamespaceForPrefix(String prefix) { if (prefix == null) { prefix = ""; } if (prefix.equals(getNamespacePrefix())) { return getNamespace(); } else if (prefix.equals("xml")) { return Namespace.XML_NAMESPACE; } else { final Object contentShadow = content; if (contentShadow instanceof List) { List<Node> list = (List<Node>) contentShadow; for (Node node : list) { if (node instanceof Namespace) { Namespace namespace = (Namespace) node; if (prefix.equals(namespace.getPrefix())) { return namespace; } } } } else if (contentShadow instanceof Namespace) { Namespace namespace = (Namespace) contentShadow; if (prefix.equals(namespace.getPrefix())) { return namespace; } } } Element parent = getParent(); if (parent != null) { Namespace answer = parent.getNamespaceForPrefix(prefix); if (answer != null) { return answer; } } if ((prefix.length() <= 0)) { return Namespace.NO_NAMESPACE; } return null; } public Namespace getNamespaceForURI(String uri) { if ((uri == null) || (uri.length() <= 0)) { return Namespace.NO_NAMESPACE; } else if (uri.equals(getNamespaceURI())) { return getNamespace(); } else { final Object contentShadow = content; if (contentShadow instanceof List) { List<Node> list = (List<Node>) contentShadow; for (Node node : list) { if (node instanceof Namespace) { Namespace namespace = (Namespace) node; if (uri.equals(namespace.getURI())) { return namespace; } } } } else if (contentShadow instanceof Namespace) { Namespace namespace = (Namespace) contentShadow; if (uri.equals(namespace.getURI())) { return namespace; } } Element parent = getParent(); if (parent != null) { return parent.getNamespaceForURI(uri); } return null; } } public List<Namespace> declaredNamespaces() { BackedList<Namespace> answer = createResultList(); // if (getNamespaceURI().length() > 0) { // // answer.addLocal(getNamespace()); // // } final Object contentShadow = content; if (contentShadow instanceof List) { List<Node> list = (List<Node>) contentShadow; for (Node node : list) { if (node instanceof Namespace) { answer.addLocal((Namespace) node); } } } else { if (contentShadow instanceof Namespace) { answer.addLocal((Namespace) contentShadow); } } return answer; } public List<Namespace> additionalNamespaces() { final Object contentShadow = content; if (contentShadow instanceof List) { List<Node> list = (List<Node>) contentShadow; BackedList<Namespace> answer = createResultList(); for (Node node : list) { if (node instanceof Namespace) { Namespace namespace = (Namespace) node; if (!namespace.equals(getNamespace())) { answer.addLocal(namespace); } } } return answer; } else { if (contentShadow instanceof Namespace) { Namespace namespace = (Namespace) contentShadow; if (namespace.equals(getNamespace())) { return createEmptyList(); } return createSingleResultList(namespace); } else { return createEmptyList(); } } } public List<Namespace> additionalNamespaces(String defaultNamespaceURI) { final Object contentShadow = content; if (contentShadow instanceof List) { List<Node> list = (List<Node>) contentShadow; BackedList<Namespace> answer = createResultList(); for (Node node : list) { if (node instanceof Namespace) { Namespace namespace = (Namespace) node; if (!defaultNamespaceURI.equals(namespace.getURI())) { answer.addLocal(namespace); } } } return answer; } else { if (contentShadow instanceof Namespace) { Namespace namespace = (Namespace) contentShadow; if (!defaultNamespaceURI.equals(namespace.getURI())) { return createSingleResultList(namespace); } } } return createEmptyList(); } // Processing instruction API public List<ProcessingInstruction> processingInstructions() { final Object contentShadow = content; if (contentShadow instanceof List) { List<Node> list = (List<Node>) contentShadow; BackedList<ProcessingInstruction> answer = createResultList(); for (Node node : list) { if (node instanceof ProcessingInstruction) { answer.addLocal((ProcessingInstruction) node); } } return answer; } else { if (contentShadow instanceof ProcessingInstruction) { return createSingleResultList((ProcessingInstruction) contentShadow); } return createEmptyList(); } } public List<ProcessingInstruction> processingInstructions(String target) { final Object shadow = content; if (shadow instanceof List) { List<Node> list = (List<Node>) shadow; BackedList<ProcessingInstruction> answer = createResultList(); for (Node node : list) { if (node instanceof ProcessingInstruction) { ProcessingInstruction pi = (ProcessingInstruction) node; if (target.equals(pi.getName())) { answer.addLocal(pi); } } } return answer; } else { if (shadow instanceof ProcessingInstruction) { ProcessingInstruction pi = (ProcessingInstruction) shadow; if (target.equals(pi.getName())) { return createSingleResultList(pi); } } return createEmptyList(); } } public ProcessingInstruction processingInstruction(String target) { final Object shadow = content; if (shadow instanceof List) { List<Node> list = (List<Node>) shadow; for (Node node : list) { if (node instanceof ProcessingInstruction) { ProcessingInstruction pi = (ProcessingInstruction) node; if (target.equals(pi.getName())) { return pi; } } } } else { if (shadow instanceof ProcessingInstruction) { ProcessingInstruction pi = (ProcessingInstruction) shadow; if (target.equals(pi.getName())) { return pi; } } } return null; } public boolean removeProcessingInstruction(String target) { final Object shadow = content; if (shadow instanceof List) { List<Node> list = (List<Node>) shadow; for (Iterator<Node> iter = list.iterator(); iter.hasNext();) { Node node = iter.next(); if (node instanceof ProcessingInstruction) { ProcessingInstruction pi = (ProcessingInstruction) node; if (target.equals(pi.getName())) { iter.remove(); return true; } } } } else { if (shadow instanceof ProcessingInstruction) { ProcessingInstruction pi = (ProcessingInstruction) shadow; if (target.equals(pi.getName())) { this.content = null; return true; } } } return false; } public Element element(String name) { final Object contentShadow = content; if (contentShadow instanceof List) { List<Node> list = (List<Node>) contentShadow; for (Node node : list) { if (node instanceof Element) { Element element = (Element) node; if (name.equals(element.getName())) { return element; } } } } else { if (contentShadow instanceof Element) { Element element = (Element) contentShadow; if (name.equals(element.getName())) { return element; } } } return null; } public Element element(QName qName) { final Object contentShadow = content; if (contentShadow instanceof List) { List<Node> list = (List<Node>) contentShadow; for (Node node : list) { if (node instanceof Element) { Element element = (Element) node; if (qName.equals(element.getQName())) { return element; } } } } else { if (contentShadow instanceof Element) { Element element = (Element) contentShadow; if (qName.equals(element.getQName())) { return element; } } } return null; } public Element element(String name, Namespace namespace) { return element(getDocumentFactory().createQName(name, namespace)); } public void setContent(List<Node> content) { contentRemoved(); if (content instanceof ContentListFacade) { content = ((ContentListFacade<Node>) content).getBackingList(); } if (content == null) { this.content = null; } else { int size = content.size(); List<Node> newContent = createContentList(size); for (Node node : content) { Element parent = node.getParent(); if ((parent != null) && (parent != this)) { node = (Node) node.clone(); } newContent.add(node); childAdded(node); } this.content = newContent; } } public void clearContent() { if (content != null) { contentRemoved(); content = null; } } public Node node(int index) { if (index >= 0) { final Object contentShadow = content; Node node; if (contentShadow instanceof List) { List<Node> list = (List<Node>) contentShadow; if (index >= list.size()) { return null; } node = list.get(index); } else { node = (index == 0) ? (Node) contentShadow : null; } return node; } return null; } public int indexOf(Node node) { final Object contentShadow = content; if (contentShadow instanceof List) { List<Node> list = (List<Node>) contentShadow; return list.indexOf(node); } else { if ((contentShadow != null) && contentShadow.equals(node)) { return 0; } else { return -1; } } } public int nodeCount() { final Object contentShadow = content; if (contentShadow instanceof List) { List<Node> list = (List<Node>) contentShadow; return list.size(); } else { return (contentShadow != null) ? 1 : 0; } } public Iterator<Node> nodeIterator() { final Object contentShadow = content; if (contentShadow instanceof List) { List<Node> list = (List<Node>) contentShadow; return list.iterator(); } else { if (contentShadow != null) { return createSingleIterator((Node) contentShadow); } else { return Collections.<Node>emptyList().iterator(); } } } public List<Attribute> attributes() { return new ContentListFacade<Attribute>(this, attributeList()); } public void setAttributes(List<Attribute> attributes) { if (attributes instanceof ContentListFacade) { attributes = ((ContentListFacade<Attribute>) attributes).getBackingList(); } this.attributes = attributes; } public Iterator<Attribute> attributeIterator() { final Object attributesShadow = this.attributes; if (attributesShadow instanceof List) { List<Attribute> list = (List<Attribute>) attributesShadow; return list.iterator(); } else if (attributesShadow != null) { return createSingleIterator((Attribute) attributesShadow); } else { return Collections.<Attribute>emptyList().iterator(); } } public Attribute attribute(int index) { final Object attributesShadow = this.attributes; if (attributesShadow instanceof List) { List<Attribute> list = (List<Attribute>) attributesShadow; return (Attribute) list.get(index); } else if ((attributesShadow != null) && (index == 0)) { return (Attribute) attributesShadow; } else { return null; } } public int attributeCount() { final Object attributesShadow = this.attributes; if (attributesShadow instanceof List) { List<Attribute> list = (List<Attribute>) attributesShadow; return list.size(); } else { return (attributesShadow != null) ? 1 : 0; } } public Attribute attribute(String name) { final Object attributesShadow = this.attributes; if (attributesShadow instanceof List) { List<Attribute> list = (List<Attribute>) attributesShadow; for (Attribute attribute : list) { if (name.equals(attribute.getName())) { return attribute; } } } else if (attributesShadow != null) { Attribute attribute = (Attribute) attributesShadow; if (name.equals(attribute.getName())) { return attribute; } } return null; } public Attribute attribute(QName qName) { final Object attributesShadow = this.attributes; if (attributesShadow instanceof List) { List<Attribute> list = (List<Attribute>) attributesShadow; for (Attribute attribute : list) { if (qName.equals(attribute.getQName())) { return attribute; } } } else if (attributesShadow != null) { Attribute attribute = (Attribute) attributesShadow; if (qName.equals(attribute.getQName())) { return attribute; } } return null; } public Attribute attribute(String name, Namespace namespace) { return attribute(getDocumentFactory().createQName(name, namespace)); } public void add(Attribute attribute) { if (attribute.getParent() != null) { String message = "The Attribute already has an existing parent \"" + attribute.getParent().getQualifiedName() + "\""; throw new IllegalAddException(this, attribute, message); } if (attribute.getValue() == null) { // try remove a previous attribute with the same // name since adding an attribute with a null value // is equivalent to removing it. Attribute oldAttribute = attribute(attribute.getQName()); if (oldAttribute != null) { remove(oldAttribute); } } else { if (attributes == null) { attributes = attribute; } else { attributeList().add(attribute); } childAdded(attribute); } } public boolean remove(Attribute attribute) { boolean answer = false; final Object attributesShadow = this.attributes; if (attributesShadow instanceof List) { List<Attribute> list = (List<Attribute>) attributesShadow; answer = list.remove(attribute); if (!answer) { // we may have a copy of the attribute Attribute copy = attribute(attribute.getQName()); if (copy != null) { list.remove(copy); answer = true; } } } else if (attributesShadow != null) { if (attribute.equals(attributesShadow)) { this.attributes = null; answer = true; } else { // we may have a copy of the attribute Attribute other = (Attribute) attributesShadow; if (attribute.getQName().equals(other.getQName())) { attributes = null; answer = true; } } } if (answer) { childRemoved(attribute); } return answer; } // Implementation methods // ------------------------------------------------------------------------- protected void addNewNode(Node node) { final Object contentShadow = content; if (contentShadow == null) { this.content = node; } else { if (contentShadow instanceof List) { List<Node> list = (List<Node>) contentShadow; list.add(node); } else { List<Node> list = createContentList(); list.add((Node) contentShadow); list.add(node); this.content = list; } } childAdded(node); } protected boolean removeNode(Node node) { boolean answer = false; final Object contentShadow = content; if (contentShadow != null) { if (contentShadow == node) { this.content = null; answer = true; } else if (contentShadow instanceof List) { List<Node> list = (List<Node>) contentShadow; answer = list.remove(node); } } if (answer) { childRemoved(node); } return answer; } protected List<Node> contentList() { final Object contentShadow = content; if (contentShadow instanceof List) { return (List<Node>) contentShadow; } else { List<Node> list = createContentList(); if (contentShadow != null) { list.add((Node) contentShadow); } this.content = list; return list; } } protected List<Attribute> attributeList() { final Object attributesShadow = this.attributes; if (attributesShadow instanceof List) { return (List<Attribute>) attributesShadow; } else if (attributesShadow != null) { List<Attribute> list = createAttributeList(); list.add((Attribute) attributesShadow); this.attributes = list; return list; } else { List<Attribute> list = createAttributeList(); this.attributes = list; return list; } } protected List<Attribute> attributeList(int size) { final Object attributesShadow = this.attributes; if (attributesShadow instanceof List) { return (List<Attribute>) attributesShadow; } else if (attributesShadow != null) { List<Attribute> list = createAttributeList(size); list.add((Attribute) attributesShadow); this.attributes = list; return list; } else { List<Attribute> list = createAttributeList(size); this.attributes = list; return list; } } protected void setAttributeList(List<Attribute> attributeList) { this.attributes = attributeList; } protected DocumentFactory getDocumentFactory() { DocumentFactory factory = qname.getDocumentFactory(); return (factory != null) ? factory : DOCUMENT_FACTORY; } } /* * 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. */