JDOM XPath Viewer，jdomxpathviewer,From the boo

JDOM XPath Viewer，jdomxpathviewer,From the boo

From the book: Hardcore JavaTitle: Java and XMLThird Edition: December2006ISBN 10: 0-596-10149-XISBN 13: 9780596101497http://www.oreilly.com/

SimpleXPathViewer.java

package javaxml3;import java.awt.*;import java.io.File;import java.io.IOException;import javax.swing.*;import javax.swing.tree.*;import javax.swing.event.*;import java.util.Iterator;// JDOM importsimport org.jdom.*;import org.jdom.input.SAXBuilder;public class SimpleXPathViewer extends JFrame {    /** The event handler inner class */    EventHandler eventHandler = new EventHandler();    /** A text field for displaying the XPath for the selectected node */    private JTextField statusText;    /** The JTree used to display the nodes of the xml do*****ent */    private JTree jdomTree;    /** The selection model used to determine which node was clicked */    private DefaultTreeSelectionModel selectionModel;    /** The filename containing the xml file to view */    private String filename;    /** Temporary hack to get around the lack of a text node */    private static Element lastElement;    class EventHandler implements TreeSelectionListener {        public void valueChanged(TreeSelectionEvent e) {            TreePath path= selectionModel.getLeadSelectionPath();            // If you are just collapsing the tree, you may not have a new path            if (path != null) {                JDOMNode selection=                    (JDOMNode)((DefaultMutableTreeNode)path.getLastPathComponent())                        .getUserObject();                buildXPath(selection);            }        };    };    public SimpleXPathViewer(String fileName) throws Exception {        super();        this.filename = fileName;        setSize(600, 450);        initialize();    }    private void initialize() throws Exception {        setTitle("Simple XPath Viewer");        // Setup the UI        initConnections();        // Load the JDOM Document        Document doc = loadDocument(filename);        // Create the initial JDOMNode from the Factory method        JDOMNode root = createNode(doc.getRootElement());        // Create the root node of the JTree and build it from the JDOM Document        DefaultMutableTreeNode treeNode =             new DefaultMutableTreeNode("Document: " + filename);        buildTree(root, treeNode);        // Add the node to the tree's model        ((DefaultTreeModel)jdomTree.getModel()).setRoot(treeNode);    }    private void initConnections() {        setDefaultCloseOperation(javax.swing.WindowConstants.DISPOSE_ON_CLOSE);        // Setup the JTree and a pane to display it in        jdomTree = new JTree();        jdomTree.setName("JDOM Tree");        jdomTree.addTreeSelectionListener(eventHandler);        selectionModel = (DefaultTreeSelectionModel)jdomTree.getSelectionModel();        getContentPane().add(new JScrollPane(jdomTree), BorderLayout.CENTER);        // Setup a text box for use in a status bar        statusText = new JTextField("Click on an element to view xpath");        JPanel statusBarPane= new JPanel();        statusBarPane.setLayout(new BorderLayout());        statusBarPane.add(statusText, BorderLayout.CENTER );        getContentPane().add(statusBarPane, BorderLayout.SOUTH);    }    private Do*****ent loadDo*****ent(String filename) throws JDOMException, IOException {        SAXBuilder builder = new SAXBuilder();        builder.setIgnoringElementContentWhitespace(true);        return builder.build(new File(filename));    }    private JDOMNode createNode(Object node) {        if (node instanceof Element) {            lastElement = (Element)node;            return new ElementNode((Element)node);        }        if (node instanceof Attribute) {            return new AttributeNode((Attribute)node);        }        if (node instanceof Text) {            return new TextNode((Text)node).setParent(lastElement);        }        // All other nodes are not implemented        return null;    }    private void buildTree(JDOMNode node, DefaultMutableTreeNode treeNode) {        // If this is a whitespace node or unhandled node, ignore it        if ((node == null) || (node.toString().trim().equals(""))) {            return;        }        DefaultMutableTreeNode newTreeNode = new DefaultMutableTreeNode(node);        // Walk over the children of the node         Iterator i = node.iterator();        while (i.hasNext()) {            // Create JDOMNodes on the children and add to the tree            JDOMNode newNode = createNode(i.next());            buildTree(newNode, newTreeNode);        }        // After all the children have been added, connect to the tree        treeNode.add(newTreeNode);    }    private void buildXPath(JDOMNode node) {        try {            statusText.setText(new XPathDisplayNode(node).getXPath());        } catch (JDOMException e) {            statusText.setText("Unable to build XPath");            e.printStackTrace();        }    }    public static void main(java.lang.String[] args) {        try {            if (args.length != 1) {                System.out.println("Usage: java javaxml3.SimpleXPathViewer " +                     "[XML Document filename]");                return;            }            /* Create the frame */            SimpleXPathViewer viewer= new SimpleXPathViewer(args[0]);            /* Add a windowListener for the windowClosedEvent */            viewer.addWindowListener(new java.awt.event.WindowAdapter() {                    public void windowClosed(java.awt.event.WindowEvent e) {                        System.exit(0);                    };                });            viewer.setVisible(true);        } catch (Exception e) {            e.printStackTrace();        }    }}