Java tutorial
/* * Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. * The ASF licenses this file to You under the Apache License, Version 2.0 * (the "License"); you may not use this file except in compliance with * the License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ import java.io.Serializable; import java.util.Hashtable; import javax.swing.JTree; import javax.swing.tree.DefaultMutableTreeNode; import javax.swing.tree.DefaultTreeModel; import javax.swing.tree.MutableTreeNode; import org.w3c.dom.Document; import org.w3c.dom.NamedNodeMap; import org.w3c.dom.Node; import org.w3c.dom.NodeList; /** * Displays a DOM document in a tree control. * * @author Andy Clark, IBM * @version $Id: DOMTree.java 447689 2006-09-19 02:40:36Z mrglavas $ */ public class DOMTree extends JTree { private static final long serialVersionUID = 3977582510937224497L; // // Constructors // /** Default constructor. */ public DOMTree() { this(null); } /** Constructs a tree with the specified document. */ public DOMTree(Document document) { super(new Model()); // set tree properties setRootVisible(false); // set properties setDocument(document); } // <init>() // // Public methods // /** Sets the document. */ public void setDocument(Document document) { ((Model) getModel()).setDocument(document); expandRow(0); } /** Returns the document. */ public Document getDocument() { return ((Model) getModel()).getDocument(); } /** get the org.w3c.Node for a MutableTreeNode. */ public Node getNode(Object treeNode) { return ((Model) getModel()).getNode(treeNode); } // // Classes // /** * DOM tree model. * * @author Andy Clark, IBM * @version */ static class Model extends DefaultTreeModel implements Serializable { private static final long serialVersionUID = 3257286915924571186L; // // Data // /** Document. */ private Document document; /** Node Map. */ private Hashtable nodeMap = new Hashtable(); // // Constructors // /** Default constructor. */ public Model() { this(null); } /** Constructs a model from the specified document. */ public Model(Document document) { super(new DefaultMutableTreeNode()); setDocument(document); } // // Public methods // /** Sets the document. */ public synchronized void setDocument(Document document) { // save document this.document = document; // clear tree and re-populate ((DefaultMutableTreeNode) getRoot()).removeAllChildren(); nodeMap.clear(); buildTree(); fireTreeStructureChanged(this, new Object[] { getRoot() }, new int[0], new Object[0]); } // setDocument(Document) /** Returns the document. */ public Document getDocument() { return document; } /** get the org.w3c.Node for a MutableTreeNode. */ public Node getNode(Object treeNode) { return (Node) nodeMap.get(treeNode); } // // Private methods // /** Builds the tree. */ private void buildTree() { // is there anything to do? if (document == null) { return; } // iterate over children of this node NodeList nodes = document.getChildNodes(); int len = (nodes != null) ? nodes.getLength() : 0; MutableTreeNode root = (MutableTreeNode) getRoot(); for (int i = 0; i < len; i++) { Node node = nodes.item(i); switch (node.getNodeType()) { case Node.DOCUMENT_NODE: { root = insertDocumentNode(node, root); break; } case Node.ELEMENT_NODE: { insertElementNode(node, root); break; } default: // ignore } // switch } // for } // buildTree() /** Inserts a node and returns a reference to the new node. */ private MutableTreeNode insertNode(String what, MutableTreeNode where) { MutableTreeNode node = new DefaultMutableTreeNode(what); insertNodeInto(node, where, where.getChildCount()); return node; } // insertNode(Node,MutableTreeNode):MutableTreeNode /** Inserts the document node. */ private MutableTreeNode insertDocumentNode(Node what, MutableTreeNode where) { MutableTreeNode treeNode = insertNode("<" + what.getNodeName() + '>', where); nodeMap.put(treeNode, what); return treeNode; } /** Inserts an element node. */ private MutableTreeNode insertElementNode(Node what, MutableTreeNode where) { // build up name StringBuffer name = new StringBuffer(); name.append('<'); name.append(what.getNodeName()); NamedNodeMap attrs = what.getAttributes(); int attrCount = (attrs != null) ? attrs.getLength() : 0; for (int i = 0; i < attrCount; i++) { Node attr = attrs.item(i); name.append(' '); name.append(attr.getNodeName()); name.append("=\""); name.append(attr.getNodeValue()); name.append('"'); } name.append('>'); // insert element node MutableTreeNode element = insertNode(name.toString(), where); nodeMap.put(element, what); // gather up attributes and children nodes NodeList children = what.getChildNodes(); int len = (children != null) ? children.getLength() : 0; for (int i = 0; i < len; i++) { Node node = children.item(i); switch (node.getNodeType()) { case Node.CDATA_SECTION_NODE: { insertCDataSectionNode(node, element); // Add a Section Node break; } case Node.TEXT_NODE: { insertTextNode(node, element); break; } case Node.ELEMENT_NODE: { insertElementNode(node, element); break; } } } return element; } // insertElementNode(Node,MutableTreeNode):MutableTreeNode /** Inserts a text node. */ private MutableTreeNode insertTextNode(Node what, MutableTreeNode where) { String value = what.getNodeValue().trim(); if (value.length() > 0) { MutableTreeNode treeNode = insertNode(value, where); nodeMap.put(treeNode, what); return treeNode; } return null; } /** Inserts a CData Section Node. */ private MutableTreeNode insertCDataSectionNode(Node what, MutableTreeNode where) { StringBuffer CSectionBfr = new StringBuffer(); CSectionBfr.append(what.getNodeValue()); if (CSectionBfr.length() > 0) { MutableTreeNode treeNode = insertNode(CSectionBfr.toString(), where); nodeMap.put(treeNode, what); return treeNode; } return null; } } // class Model } // class DOMTree