corejava/corejava第8版/v2ch02/DOMTreeTest/DOMTreeTest.java

import java.awt.*;
import java.awt.event.*;
import java.io.*;
import javax.swing.*;
import javax.swing.event.*;
import javax.swing.table.*;
import javax.swing.tree.*;
import javax.xml.parsers.*;
import org.w3c.dom.*;

/**
 * This program displays an XML document as a tree.
 * @version 1.11 2007-06-24
 * @author Cay Horstmann
 */
public class DOMTreeTest
{
   public static void main(String[] args)
   {
      EventQueue.invokeLater(new Runnable()
         {
            public void run()
            {
               JFrame frame = new DOMTreeFrame();
               frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
               frame.setVisible(true);
            }
         });
   }
}

/**
 * This frame contains a tree that displays the contents of an XML document.
 */
class DOMTreeFrame extends JFrame
{
   public DOMTreeFrame()
   {
      setTitle("DOMTreeTest");
      setSize(DEFAULT_WIDTH, DEFAULT_HEIGHT);

      JMenu fileMenu = new JMenu("File");
      JMenuItem openItem = new JMenuItem("Open");
      openItem.addActionListener(new ActionListener()
         {
            public void actionPerformed(ActionEvent event)
            {
               openFile();
            }
         });
      fileMenu.add(openItem);

      JMenuItem exitItem = new JMenuItem("Exit");
      exitItem.addActionListener(new ActionListener()
         {
            public void actionPerformed(ActionEvent event)
            {
               System.exit(0);
            }
         });
      fileMenu.add(exitItem);

      JMenuBar menuBar = new JMenuBar();
      menuBar.add(fileMenu);
      setJMenuBar(menuBar);
   }

   /**
    * Open a file and load the document.
    */
   public void openFile()
   {
      JFileChooser chooser = new JFileChooser();
      chooser.setCurrentDirectory(new File("."));

      chooser.setFileFilter(new javax.swing.filechooser.FileFilter()
         {
            public boolean accept(File f)
            {
               return f.isDirectory() || f.getName().toLowerCase().endsWith(".xml");
            }

            public String getDescription()
            {
               return "XML files";
            }
         });
      int r = chooser.showOpenDialog(this);
      if (r != JFileChooser.APPROVE_OPTION) return;
      final File file = chooser.getSelectedFile();

      new SwingWorker<Document, Void>()
         {
            protected Document doInBackground() throws Exception
            {
               if (builder == null)
               {
                  DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
                  builder = factory.newDocumentBuilder();
               }
               return builder.parse(file);
            }

            protected void done()
            {
               try
               {
                  Document doc = get();
                  JTree tree = new JTree(new DOMTreeModel(doc));
                  tree.setCellRenderer(new DOMTreeCellRenderer());

                  setContentPane(new JScrollPane(tree));
                  validate();
               }
               catch (Exception e)
               {
                  JOptionPane.showMessageDialog(DOMTreeFrame.this, e);
               }
            }
         }.execute();
   }

   private DocumentBuilder builder;
   private static final int DEFAULT_WIDTH = 400;
   private static final int DEFAULT_HEIGHT = 400;
}

/**
 * This tree model describes the tree structure of an XML document.
 */
class DOMTreeModel implements TreeModel
{
   /**
    * Constructs a document tree model.
    * @param doc the document
    */
   public DOMTreeModel(Document doc)
   {
      this.doc = doc;
   }

   public Object getRoot()
   {
      return doc.getDocumentElement();
   }

   public int getChildCount(Object parent)
   {
      Node node = (Node) parent;
      NodeList list = node.getChildNodes();
      return list.getLength();
   }

   public Object getChild(Object parent, int index)
   {
      Node node = (Node) parent;
      NodeList list = node.getChildNodes();
      return list.item(index);
   }

   public int getIndexOfChild(Object parent, Object child)
   {
      Node node = (Node) parent;
      NodeList list = node.getChildNodes();
      for (int i = 0; i < list.getLength(); i++)
         if (getChild(node, i) == child) return i;
      return -1;
   }

   public boolean isLeaf(Object node)
   {
      return getChildCount(node) == 0;
   }

   public void valueForPathChanged(TreePath path, Object newValue)
   {
   }

   public void addTreeModelListener(TreeModelListener l)
   {
   }

   public void removeTreeModelListener(TreeModelListener l)
   {
   }

   private Document doc;
}

/**
 * This class renders an XML node.
 */
class DOMTreeCellRenderer extends DefaultTreeCellRenderer
{
   public Component getTreeCellRendererComponent(JTree tree, Object value, boolean selected,
         boolean expanded, boolean leaf, int row, boolean hasFocus)
   {
      Node node = (Node) value;
      if (node instanceof Element) return elementPanel((Element) node);

      super.getTreeCellRendererComponent(tree, value, selected, expanded, leaf, row, hasFocus);
      if (node instanceof CharacterData) setText(characterString((CharacterData) node));
      else setText(node.getClass() + ": " + node.toString());
      return this;
   }

   public static JPanel elementPanel(Element e)
   {
      JPanel panel = new JPanel();
      panel.add(new JLabel("Element: " + e.getTagName()));
      final NamedNodeMap map = e.getAttributes();
      panel.add(new JTable(new AbstractTableModel()
         {
            public int getRowCount()
            {
               return map.getLength();
            }

            public int getColumnCount()
            {
               return 2;
            }

            public Object getValueAt(int r, int c)
            {
               return c == 0 ? map.item(r).getNodeName() : map.item(r).getNodeValue();
            }
         }));
      return panel;
   }

   public static String characterString(CharacterData node)
   {
      StringBuilder builder = new StringBuilder(node.getData());
      for (int i = 0; i < builder.length(); i++)
      {
         if (builder.charAt(i) == '\r')
         {
            builder.replace(i, i + 1, "\\r");
            i++;
         }
         else if (builder.charAt(i) == '\n')
         {
            builder.replace(i, i + 1, "\\n");
            i++;
         }
         else if (builder.charAt(i) == '\t')
         {
            builder.replace(i, i + 1, "\\t");
            i++;
         }
      }
      if (node instanceof CDATASection) builder.insert(0, "CDATASection: ");
      else if (node instanceof Text) builder.insert(0, "Text: ");
      else if (node instanceof Comment) builder.insert(0, "Comment: ");

      return builder.toString();
   }
}