VSX.java Source code

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Here is the source code for VSX.java

Source

/*
Java Swing, 2nd Edition
By Marc Loy, Robert Eckstein, Dave Wood, James Elliott, Brian Cole
ISBN: 0-596-00408-7
Publisher: O'Reilly 
*/
// VSX.java
//A simple XML parser that builds a tree from SAX events. 
//

import java.io.File;

import javax.swing.JFrame;
import javax.swing.JScrollPane;
import javax.swing.JTree;
import javax.swing.tree.DefaultMutableTreeNode;
import javax.swing.tree.DefaultTreeModel;
import javax.swing.tree.TreeModel;
import javax.xml.parsers.SAXParser;
import javax.xml.parsers.SAXParserFactory;

import org.xml.sax.Attributes;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.DefaultHandler;

public class VSX {

    public TreeModel parse(String filename) {
        SAXParserFactory factory = SAXParserFactory.newInstance();
        XMLTreeHandler handler = new XMLTreeHandler();
        try {
            // Parse the input.
            SAXParser saxParser = factory.newSAXParser();
            saxParser.parse(new File(filename), handler);
        } catch (Exception e) {
            System.err.println("File Read Error: " + e);
            e.printStackTrace();
            return new DefaultTreeModel(new DefaultMutableTreeNode("error"));
        }
        return new DefaultTreeModel(handler.getRoot());
    }

    public static class XMLTreeHandler extends DefaultHandler {
        private DefaultMutableTreeNode root, currentNode;

        public DefaultMutableTreeNode getRoot() {
            return root;
        }

        // SAX Parser Handler methods...
        public void startElement(String namespaceURI, String lName, String qName, Attributes attrs)
                throws SAXException {
            String eName = lName; // Element name
            if ("".equals(eName))
                eName = qName;
            Tag t = new Tag(eName, attrs);
            DefaultMutableTreeNode newNode = new DefaultMutableTreeNode(t);
            if (currentNode == null) {
                root = newNode;
            } else {
                // Must not be the root node...
                currentNode.add(newNode);
            }
            currentNode = newNode;
        }

        public void endElement(String namespaceURI, String sName, String qName) throws SAXException {
            currentNode = (DefaultMutableTreeNode) currentNode.getParent();
        }

        public void characters(char buf[], int offset, int len) throws SAXException {
            String s = new String(buf, offset, len).trim();
            ((Tag) currentNode.getUserObject()).addData(s);
        }
    }

    public static class Tag {
        private String name;

        private String data;

        private Attributes attr;

        public Tag(String n, Attributes a) {
            name = n;
            attr = a;
        }

        public String getName() {
            return name;
        }

        public Attributes getAttributes() {
            return attr;
        }

        public void setData(String d) {
            data = d;
        }

        public String getData() {
            return data;
        }

        public void addData(String d) {
            if (data == null) {
                setData(d);
            } else {
                data += d;
            }
        }

        public String getAttributesAsString() {
            StringBuffer buf = new StringBuffer(256);
            for (int i = 0; i < attr.getLength(); i++) {
                buf.append(attr.getQName(i));
                buf.append("=\"");
                buf.append(attr.getValue(i));
                buf.append("\"");
            }
            return buf.toString();
        }

        public String toString() {
            String a = getAttributesAsString();
            return name + ": " + a + (data == null ? "" : " (" + data + ")");
        }
    }

    public static void main(String args[]) {
        JFrame frame = new JFrame("VSX Test");
        VSX parser = new VSX();
        JTree tree = new JTree(parser.parse("build.xml"));
        frame.getContentPane().add(new JScrollPane(tree));
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setSize(300, 400);
        frame.setVisible(true);
    }
}