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.dom; import org.dom4j.*; import org.w3c.dom.DOMException; import org.w3c.dom.NamedNodeMap; import org.w3c.dom.NodeList; import java.util.List; /** * <p> * <code>DOMNodeHelper</code> contains a collection of utility methods for use * across Node implementations. * </p> * * @author <a href="mailto:james.strachan@metastuff.com">James Strachan </a> * @version $Revision: 1.20 $ */ public class DOMNodeHelper { public static final NodeList EMPTY_NODE_LIST = new EmptyNodeList(); protected DOMNodeHelper() { } // Node API // ------------------------------------------------------------------------- public static boolean supports(Node node, String feature, String version) { return false; } public static String getNamespaceURI(Node node) { return null; } public static String getPrefix(Node node) { return null; } public static String getLocalName(Node node) { return null; } public static void setPrefix(Node node, String prefix) throws DOMException { notSupported(); } public static String getNodeValue(Node node) throws DOMException { return node.getText(); } public static void setNodeValue(Node node, String nodeValue) throws DOMException { node.setText(nodeValue); } public static org.w3c.dom.Node getParentNode(Node node) { return asDOMNode(node.getParent()); } public static NodeList getChildNodes(Node node) { return EMPTY_NODE_LIST; } public static org.w3c.dom.Node getFirstChild(Node node) { return null; } public static org.w3c.dom.Node getLastChild(Node node) { return null; } public static org.w3c.dom.Node getPreviousSibling(Node node) { Element parent = node.getParent(); if (parent != null) { int index = parent.indexOf(node); if (index > 0) { Node previous = parent.node(index - 1); return asDOMNode(previous); } } return null; } public static org.w3c.dom.Node getNextSibling(Node node) { Element parent = node.getParent(); if (parent != null) { int index = parent.indexOf(node); if (index >= 0) { if (++index < parent.nodeCount()) { Node next = parent.node(index); return asDOMNode(next); } } } return null; } public static NamedNodeMap getAttributes(Node node) { return null; } public static org.w3c.dom.Document getOwnerDocument(Node node) { return asDOMDocument(node.getDocument()); } public static org.w3c.dom.Node insertBefore(Node node, org.w3c.dom.Node newChild, org.w3c.dom.Node refChild) throws DOMException { if (node instanceof Branch) { assert newChild instanceof Node; Branch branch = (Branch) node; List<Node> list = branch.content(); int index = list.indexOf(refChild); if (index < 0) { branch.add((Node) newChild); } else { list.add(index, (Node) newChild); } return newChild; } else { throw new DOMException(DOMException.HIERARCHY_REQUEST_ERR, "Children not allowed for this node: " + node); } } public static org.w3c.dom.Node replaceChild(Node node, org.w3c.dom.Node newChild, org.w3c.dom.Node oldChild) throws DOMException { if (node instanceof Branch) { Branch branch = (Branch) node; List<Node> list = branch.content(); assert newChild instanceof Node; int index = list.indexOf(oldChild); if (index < 0) { throw new DOMException(DOMException.NOT_FOUND_ERR, "Tried to replace a non existing child " + "for node: " + node); } list.set(index, (Node) newChild); return oldChild; } else { throw new DOMException(DOMException.HIERARCHY_REQUEST_ERR, "Children not allowed for this node: " + node); } } public static org.w3c.dom.Node removeChild(Node node, org.w3c.dom.Node oldChild) throws DOMException { if (node instanceof Branch) { Branch branch = (Branch) node; branch.remove((Node) oldChild); return oldChild; } throw new DOMException(DOMException.HIERARCHY_REQUEST_ERR, "Children not allowed for this node: " + node); } public static org.w3c.dom.Node appendChild(Node node, org.w3c.dom.Node newChild) throws DOMException { if (node instanceof Branch) { Branch branch = (Branch) node; org.w3c.dom.Node previousParent = newChild.getParentNode(); if (previousParent != null) { previousParent.removeChild(newChild); } branch.add((Node) newChild); return newChild; } throw new DOMException(DOMException.HIERARCHY_REQUEST_ERR, "Children not allowed for this node: " + node); } public static boolean hasChildNodes(Node node) { return false; } public static org.w3c.dom.Node cloneNode(Node node, boolean deep) { return asDOMNode((Node) node.clone()); } public static void normalize(Node node) { notSupported(); } public static boolean isSupported(Node n, String feature, String version) { return false; } public static boolean hasAttributes(Node node) { if ((node != null) && node instanceof Element) { return ((Element) node).attributeCount() > 0; } else { return false; } } // CharacterData API // ------------------------------------------------------------------------- public static String getData(CharacterData charData) throws DOMException { return charData.getText(); } public static void setData(CharacterData charData, String data) throws DOMException { charData.setText(data); } public static int getLength(CharacterData charData) { String text = charData.getText(); return (text != null) ? text.length() : 0; } public static String substringData(CharacterData charData, int offset, int count) throws DOMException { if (count < 0) { throw new DOMException(DOMException.INDEX_SIZE_ERR, "Illegal value for count: " + count); } String text = charData.getText(); int length = (text != null) ? text.length() : 0; if ((offset < 0) || (offset >= length)) { throw new DOMException(DOMException.INDEX_SIZE_ERR, "No text at offset: " + offset); } if ((offset + count) > length) { return text.substring(offset); } return text.substring(offset, offset + count); } public static void appendData(CharacterData charData, String arg) throws DOMException { if (charData.isReadOnly()) { throw new DOMException(DOMException.NO_MODIFICATION_ALLOWED_ERR, "CharacterData node is read only: " + charData); } else { String text = charData.getText(); if (text == null) { charData.setText(arg); } else { charData.setText(text + arg); } } } public static void insertData(CharacterData data, int offset, String arg) throws DOMException { if (data.isReadOnly()) { throw new DOMException(DOMException.NO_MODIFICATION_ALLOWED_ERR, "CharacterData node is read only: " + data); } else { String text = data.getText(); if (text == null) { data.setText(arg); } else { int length = text.length(); if ((offset < 0) || (offset > length)) { throw new DOMException(DOMException.INDEX_SIZE_ERR, "No text at offset: " + offset); } else { StringBuilder buffer = new StringBuilder(text); buffer.insert(offset, arg); data.setText(buffer.toString()); } } } } public static void deleteData(CharacterData charData, int offset, int count) throws DOMException { if (charData.isReadOnly()) { throw new DOMException(DOMException.NO_MODIFICATION_ALLOWED_ERR, "CharacterData node is read only: " + charData); } else { if (count < 0) { throw new DOMException(DOMException.INDEX_SIZE_ERR, "Illegal value for count: " + count); } String text = charData.getText(); if (text != null) { int length = text.length(); if ((offset < 0) || (offset >= length)) { throw new DOMException(DOMException.INDEX_SIZE_ERR, "No text at offset: " + offset); } else { StringBuilder buffer = new StringBuilder(text); buffer.delete(offset, offset + count); charData.setText(buffer.toString()); } } } } public static void replaceData(CharacterData charData, int offset, int count, String arg) throws DOMException { if (charData.isReadOnly()) { throw new DOMException(DOMException.NO_MODIFICATION_ALLOWED_ERR, "CharacterData node is read only: " + charData); } else { if (count < 0) { throw new DOMException(DOMException.INDEX_SIZE_ERR, "Illegal value for count: " + count); } String text = charData.getText(); if (text != null) { int length = text.length(); if ((offset < 0) || (offset >= length)) { throw new DOMException(DOMException.INDEX_SIZE_ERR, "No text at offset: " + offset); } else { StringBuilder buffer = new StringBuilder(text); buffer.replace(offset, offset + count, arg); charData.setText(buffer.toString()); } } } } // Branch API // ------------------------------------------------------------------------- public static void appendElementsByTagName(List<? super Element> list, Branch parent, String name) { final boolean isStar = "*".equals(name); for (int i = 0, size = parent.nodeCount(); i < size; i++) { Node node = parent.node(i); if (node instanceof Element) { Element element = (Element) node; if (isStar || name.equals(element.getName())) { list.add(element); } appendElementsByTagName(list, element, name); } } } public static void appendElementsByTagNameNS(List<? super Element> list, Branch parent, String namespace, String localName) { final boolean isStarNS = "*".equals(namespace); final boolean isStar = "*".equals(localName); for (int i = 0, size = parent.nodeCount(); i < size; i++) { Node node = parent.node(i); if (node instanceof Element) { Element element = (Element) node; if ((isStarNS || (((namespace == null) || (namespace.length() == 0)) && ((element.getNamespaceURI() == null) || (element.getNamespaceURI().length() == 0))) || ((namespace != null) && namespace.equals(element.getNamespaceURI()))) && (isStar || localName.equals(element.getName()))) { list.add(element); } appendElementsByTagNameNS(list, element, namespace, localName); } } } // Helper methods // ------------------------------------------------------------------------- public static NodeList createNodeList(final List<Node> list) { return new NodeList() { public org.w3c.dom.Node item(int index) { if (index >= getLength()) { /* * From the NodeList specification: If index is greater than * or equal to the number of nodes in the list, this returns * null. */ return null; } else { return DOMNodeHelper.asDOMNode(list.get(index)); } } public int getLength() { return list.size(); } }; } public static org.w3c.dom.Node asDOMNode(Node node) { if (node == null) { return null; } if (node instanceof org.w3c.dom.Node) { return (org.w3c.dom.Node) node; } else { // Use DOMWriter? System.out.println("Cannot convert: " + node + " into a W3C DOM Node"); notSupported(); return null; } } public static org.w3c.dom.Document asDOMDocument(Document document) { if (document == null) { return null; } if (document instanceof org.w3c.dom.Document) { return (org.w3c.dom.Document) document; } else { // Use DOMWriter? notSupported(); return null; } } public static org.w3c.dom.DocumentType asDOMDocumentType(DocumentType dt) { if (dt == null) { return null; } if (dt instanceof org.w3c.dom.DocumentType) { return (org.w3c.dom.DocumentType) dt; } else { // Use DOMWriter? notSupported(); return null; } } public static org.w3c.dom.Text asDOMText(CharacterData text) { if (text == null) { return null; } if (text instanceof org.w3c.dom.Text) { return (org.w3c.dom.Text) text; } else { // Use DOMWriter? notSupported(); return null; } } public static org.w3c.dom.Element asDOMElement(Node element) { if (element == null) { return null; } if (element instanceof org.w3c.dom.Element) { return (org.w3c.dom.Element) element; } else { // Use DOMWriter? notSupported(); return null; } } public static org.w3c.dom.Attr asDOMAttr(Node attribute) { if (attribute == null) { return null; } if (attribute instanceof org.w3c.dom.Attr) { return (org.w3c.dom.Attr) attribute; } else { // Use DOMWriter? notSupported(); return null; } } /** * Called when a method has not been implemented yet * * @throws DOMException * DOCUMENT ME! */ public static void notSupported() { throw new DOMException(DOMException.NOT_SUPPORTED_ERR, "Not supported yet"); } public static class EmptyNodeList implements NodeList { public org.w3c.dom.Node item(int index) { return null; } public int getLength() { return 0; } } public static boolean isStringEquals(String string1, String string2) { if (string1 == null && string2 == null) { return true; } if (string1 == null || string2 == null) { return false; } return string1.equals(string2); } public static boolean isNodeEquals(org.w3c.dom.Node node1, org.w3c.dom.Node node2) { if (node1 == null && node2 == null) { return true; } if (node1 == null || node2 == null) { return false; } if (node1.getNodeType() != node2.getNodeType()) { return false; } if (!isStringEquals(node1.getNodeName(), node2.getNodeName())) { return false; } if (!isStringEquals(node1.getLocalName(), node2.getLocalName())) { return false; } if (!isStringEquals(node1.getNamespaceURI(), node2.getNamespaceURI())) { return false; } if (!isStringEquals(node1.getPrefix(), node2.getPrefix())) { return false; } if (!isStringEquals(node1.getNodeValue(), node2.getNodeValue())) { return false; } return true; } public static boolean isNodeSame(org.w3c.dom.Node node1, org.w3c.dom.Node node2) { return node1 == node2; } } /* * 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. */