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.util; import java.util.Comparator; import org.dom4j.Attribute; import org.dom4j.Branch; import org.dom4j.CDATA; import org.dom4j.CharacterData; import org.dom4j.Comment; import org.dom4j.Document; import org.dom4j.DocumentType; import org.dom4j.Element; import org.dom4j.Entity; import org.dom4j.Namespace; import org.dom4j.Node; import org.dom4j.ProcessingInstruction; import org.dom4j.QName; import org.dom4j.Text; /** * <p> * <code>NodeComparator</code> is a {@link Comparator}of Node instances which * is capable of comparing Nodes for equality based on their values. * </p> * * @author <a href="mailto:jstrachan@apache.org">James Strachan </a> * @version $Revision: 1.10 $ */ public class NodeComparator implements Comparator<Node> { public int compare(Node n1, Node n2) { int nodeType1 = n1.getNodeType(); int nodeType2 = n2.getNodeType(); int answer = nodeType1 - nodeType2; if (answer != 0) { return answer; } else { switch (nodeType1) { case Node.ELEMENT_NODE: return compare((Element) n1, (Element) n2); case Node.DOCUMENT_NODE: return compare((Document) n1, (Document) n2); case Node.ATTRIBUTE_NODE: return compare((Attribute) n1, (Attribute) n2); case Node.TEXT_NODE: return compare((Text) n1, (Text) n2); case Node.CDATA_SECTION_NODE: return compare((CDATA) n1, (CDATA) n2); case Node.ENTITY_REFERENCE_NODE: return compare((Entity) n1, (Entity) n2); case Node.PROCESSING_INSTRUCTION_NODE: return compare((ProcessingInstruction) n1, (ProcessingInstruction) n2); case Node.COMMENT_NODE: return compare((Comment) n1, (Comment) n2); case Node.DOCUMENT_TYPE_NODE: return compare((DocumentType) n1, (DocumentType) n2); case Node.NAMESPACE_NODE: return compare((Namespace) n1, (Namespace) n2); default: throw new RuntimeException("Invalid node types. node1: " + n1 + " and node2: " + n2); } } } public int compare(Document n1, Document n2) { int answer = compare(n1.getDocType(), n2.getDocType()); if (answer == 0) { answer = compareContent(n1, n2); } return answer; } public int compare(Element n1, Element n2) { int answer = compare(n1.getQName(), n2.getQName()); if (answer == 0) { // lets compare attributes int c1 = n1.attributeCount(); int c2 = n2.attributeCount(); answer = c1 - c2; if (answer == 0) { for (int i = 0; i < c1; i++) { Attribute a1 = n1.attribute(i); Attribute a2 = n2.attribute(a1.getQName()); answer = compare(a1, a2); if (answer != 0) { return answer; } } answer = compareContent(n1, n2); } } return answer; } public int compare(Attribute n1, Attribute n2) { int answer = compare(n1.getQName(), n2.getQName()); if (answer == 0) { answer = compare(n1.getValue(), n2.getValue()); } return answer; } public int compare(QName n1, QName n2) { int answer = compare(n1.getNamespaceURI(), n2.getNamespaceURI()); if (answer == 0) { answer = compare(n1.getQualifiedName(), n2.getQualifiedName()); } return answer; } public int compare(Namespace n1, Namespace n2) { int answer = compare(n1.getURI(), n2.getURI()); if (answer == 0) { answer = compare(n1.getPrefix(), n2.getPrefix()); } return answer; } public int compare(CharacterData t1, CharacterData t2) { return compare(t1.getText(), t2.getText()); } public int compare(DocumentType o1, DocumentType o2) { if (o1 == o2) { return 0; } else if (o1 == null) { // null is less return -1; } else if (o2 == null) { return 1; } int answer = compare(o1.getPublicID(), o2.getPublicID()); if (answer == 0) { answer = compare(o1.getSystemID(), o2.getSystemID()); if (answer == 0) { answer = compare(o1.getName(), o2.getName()); } } return answer; } public int compare(Entity n1, Entity n2) { int answer = compare(n1.getName(), n2.getName()); if (answer == 0) { answer = compare(n1.getText(), n2.getText()); } return answer; } public int compare(ProcessingInstruction n1, ProcessingInstruction n2) { int answer = compare(n1.getTarget(), n2.getTarget()); if (answer == 0) { answer = compare(n1.getText(), n2.getText()); } return answer; } public int compareContent(Branch b1, Branch b2) { int c1 = b1.nodeCount(); int c2 = b2.nodeCount(); int answer = c1 - c2; if (answer == 0) { for (int i = 0; i < c1; i++) { Node n1 = b1.node(i); Node n2 = b2.node(i); answer = compare(n1, n2); if (answer != 0) { break; } } } return answer; } public int compare(String o1, String o2) { if (o1 == o2) { return 0; } else if (o1 == null) { // null is less return -1; } else if (o2 == null) { return 1; } return o1.compareTo(o2); } } /* * 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. */