filetreeframe.java

java 编程源代码

// FileTreeFrame.java
// JFrame for displaying file system contents in a JTree
// using a custom TreeModel.
package com.deitel.advjhtp1.mvc.tree.filesystem;

// Java core packages
import java.io.*;
import java.awt.*;
import java.awt.event.*;

// Java extension packages
import javax.swing.*;
import javax.swing.tree.*;
import javax.swing.event.*;

public class FileTreeFrame extends JFrame {

   // JTree for displaying file system
   private JTree fileTree;
   
   // FileSystemModel TreeModel implementation
   private FileSystemModel fileSystemModel;
   
   // JTextArea for displaying selected file's details
   private JTextArea fileDetailsTextArea;

   // FileTreeFrame constructor
   public FileTreeFrame( String directory ) 
   {      
      super( "JTree FileSystem Viewer" );
      
      // create JTextArea for displaying File information
      fileDetailsTextArea = new JTextArea();
      fileDetailsTextArea.setEditable( false );
      
      // create FileSystemModel for given directory
      fileSystemModel = new FileSystemModel( 
         new File( directory ) );
      
      // create JTree for FileSystemModel
      fileTree = new JTree( fileSystemModel );
      
      // make JTree editable for renaming Files
      fileTree.setEditable( true );
      
      // add a TreeSelectionListener
      fileTree.addTreeSelectionListener( 
         new TreeSelectionListener() {
            
            // display details of newly selected File when
            // selection changes
            public void valueChanged( 
               TreeSelectionEvent event ) 
            {  
               File file = ( File ) 
                  fileTree.getLastSelectedPathComponent();
               
               fileDetailsTextArea.setText( 
                  getFileDetails( file ) );
            }
         }
      ); // end addTreeSelectionListener
            
      // put fileTree and fileDetailsTextArea in a JSplitPane
      JSplitPane splitPane = new JSplitPane(
         JSplitPane.HORIZONTAL_SPLIT, true, 
         new JScrollPane( fileTree ), 
         new JScrollPane( fileDetailsTextArea ) );

      getContentPane().add( splitPane );
      
      setDefaultCloseOperation( EXIT_ON_CLOSE );      
      setSize( 640, 480 );
      setVisible( true );
   }
   
   // build a String to display file details
   private String getFileDetails( File file )
   {
      // do not return details for null Files
      if ( file == null )
         return "";
      
      // put File information in a StringBuffer
      StringBuffer buffer = new StringBuffer();
      buffer.append( "Name: " + file.getName() + "\n" );
      buffer.append( "Path: " + file.getPath()  + "\n" );
      buffer.append( "Size: " + file.length() + "\n" );
      
      return buffer.toString();
   }
   
   // execute application
   public static void main( String args[] )
   {
      // ensure that user provided directory name
      if ( args.length != 1 )
         System.err.println( 
            "Usage: java FileTreeFrame <path>" );
      
      // start application using provided directory name
      else
         new FileTreeFrame( args[ 0 ] );
   }
}

/***************************************************************
 * (C) Copyright 2002 by Deitel & Associates, Inc. and         *
 * Prentice Hall. All Rights Reserved.                         *
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 * DISCLAIMER: The authors and publisher of this book have     *
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 * efforts include the development, research, and testing of   *
 * the theories and programs to determine their effectiveness. *
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