用java来实现xml的例子.rar_XML java_xml

/* * Copyright (c) 2000 David Flanagan. All rights reserved. * This code is from the book Java Examples in a Nutshell, 2nd Edition. * It is provided AS-IS, WITHOUT ANY WARRANTY either expressed or implied. * You may study, use, and modify it for any non-commercial purpose. * You may distribute it non-commercially as long as you retain this notice. * For a commercial use license, or to purchase the book (recommended), * visit http://www.davidflanagan.com/javaexamples2. */ package com.davidflanagan.examples.xml; import org.w3c.dom.*; // Core DOM classes import org.w3c.dom.traversal.*; // TreeWalker and related DOM classes import org.apache.xerces.parsers.*; // Apache Xerces parser classes import org.xml.sax.*; // Xerces DOM parser uses some SAX classes import javax.swing.*; // Swing classes import javax.swing.tree.*; // TreeModel and related classes import javax.swing.event.*; // Tree-related event classes import java.io.*; // For reading the input XML file /** * This class implements the Swing TreeModel interface so that the DOM tree * returned by a TreeWalker can be displayed in a JTree component. **/ public class DOMTreeWalkerTreeModel implements TreeModel { TreeWalker walker; // The TreeWalker we're modeling for JTree /** Create a TreeModel for the specified TreeWalker */ public DOMTreeWalkerTreeModel(TreeWalker walker) { this.walker = walker; } /** * Create a TreeModel for a TreeWalker that returns all nodes * in the specified document **/ public DOMTreeWalkerTreeModel(Document document) { DocumentTraversal dt = (DocumentTraversal)document; walker = dt.createTreeWalker(document, NodeFilter.SHOW_ALL,null,false); } /** * Create a TreeModel for a TreeWalker that returns the specified * element and all of its descendant nodes. **/ public DOMTreeWalkerTreeModel(Element element) { DocumentTraversal dt = (DocumentTraversal)element.getOwnerDocument(); walker = dt.createTreeWalker(element, NodeFilter.SHOW_ALL, null,false); } // Return the root of the tree public Object getRoot() { return walker.getRoot(); } // Is this node a leaf? (Leaf nodes are displayed differently by JTree) public boolean isLeaf(Object node) { walker.setCurrentNode((Node)node); // Set current node Node child = walker.firstChild(); // Ask for a child return (child == null); // Does it have any? } // How many children does this node have? public int getChildCount(Object node) { walker.setCurrentNode((Node)node); // Set the current node // TreeWalker doesn't count children for us, so we count ourselves int numkids = 0; Node child = walker.firstChild(); // Start with the first child while(child != null) { // Loop 'till there are no more numkids++; // Update the count child = walker.nextSibling(); // Get next child } return numkids; // This is the number of children } // Return the specified child of a parent node. public Object getChild(Object parent, int index) { walker.setCurrentNode((Node)parent); // Set the current node // TreeWalker provides sequential access to children, not random // access, so we've got to loop through the kids one by one Node child = walker.firstChild(); while(index-- > 0) child = walker.nextSibling(); return child; } // Return the index of the child node in the parent node public int getIndexOfChild(Object parent, Object child) { walker.setCurrentNode((Node)parent); // Set current node int index = 0; Node c = walker.firstChild(); // Start with first child while((c != child) && (c != null)) { // Loop 'till we find a match index++; c = walker.nextSibling(); // Get the next child } return index; // Return matching position } // Only required for editable trees; unimplemented here. public void valueForPathChanged(TreePath path, Object newvalue) {} // This TreeModel never fires any events (since it is not editable) // so event listener registration methods are left unimplemented public void addTreeModelListener(TreeModelListener l) {} public void removeTreeModelListener(TreeModelListener l) {} /** * This main() method demonstrates the use of this class, the use of the * Xerces DOM parser, and the creation of a DOM Level 2 TreeWalker object. **/ public static void main(String[] args) throws IOException, SAXException { // Obtain an instance of a Xerces parser to build a DOM tree. // Note that we are not using the JAXP API here, so this // code uses Apache Xerces APIs that are not standards DOMParser parser = new org.apache.xerces.parsers.DOMParser(); // Get a java.io.Reader for the input XML file and // wrap the input file in a SAX input source Reader in = new BufferedReader(new FileReader(args[0])); InputSource input = new org.xml.sax.InputSource(in); // Tell the Xerces parser to parse the input source parser.parse(input); // Ask the parser to give us our DOM Document. Once we've got the DOM // tree, we don't have to use the Apache Xerces APIs any more; from // here on, we use the standard DOM APIs Document document = parser.getDocument(); // If we're using a DOM Level 2 implementation, then our Document // object ought to implement DocumentTraversal DocumentTraversal traversal = (DocumentTraversal)document; // For this demonstration, we create a NodeFilter that filters out // Text nodes containing only space; these just clutter up the tree NodeFilter filter = new NodeFilter() { public short acceptNode(Node n) { if (n.getNodeType() == Node.TEXT_NODE) { // Use trim() to strip off leading and trailing space. // If nothing is left, then reject the node if (((Text)n).getData().trim().length() == 0) return NodeFilter.FILTER_REJECT; } return NodeFilter.FILTER_ACCEPT; } }; // This set of flags says to "show" all node types except comments int whatToShow = NodeFilter.SHOW_ALL & ~NodeFilter.SHOW_COMMENT; // Create a TreeWalker using the filter and the flags TreeWalker walker = traversal.createTreeWalker(document, whatToShow, filter, false); // Instantiate a TreeModel and a JTree to display it JTree tree = new JTree(new DOMTreeWalkerTreeModel(walker)); // Create a frame and a scrollpane to display the tree, and pop them up JFrame frame = new JFrame("DOMTreeWalkerTreeModel Demo"); frame.getContentPane().add(new JScrollPane(tree)); frame.setSize(500, 250); frame.setVisible(true); } }