Renaming all files in a directory. 1

[kodr]

I'm stuck and can't quite figure out what I'm doing wrong.

I'm trying to change the extensions of every file in a selected directory.

Here's what I've got:

import java.awt.*;
import java.awt.event.*;	// ActionListener
import javax.swing.*;
import java.io.File;
import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;

public class FileRenamer2 extends JFrame
{
	JPanel main = new JPanel(new BorderLayout() );
	JPanel scPane = new JPanel( new GridLayout( 1, 2, 5, 5 ) );
	JPanel btnPane = new JPanel( new FlowLayout() );

	JButton btn;
	String face = "Open File";

	private JTextArea outputArea, outputArea2;
	private JScrollPane scrollPane, scrollPane2;

	// main method
	public static void main( String args[] )
	{
		new FileRenamer2();
	}

	// set-up GUI
	public FileRenamer2()
	{
		super("TestApp");
		setBounds(100,100,800,800);
    	setDefaultCloseOperation(EXIT_ON_CLOSE);
		Handler handler = new Handler();	// Create bhandler (button handler)

		outputArea = new JTextArea();
		scrollPane = new JScrollPane( outputArea );

		outputArea2 = new JTextArea();
		scrollPane2 = new JScrollPane( outputArea2 );

		scPane.add( scrollPane );
		scPane.add( scrollPane2 );

		btn = new JButton( face );
		btnPane.add( btn );
		btn.addActionListener( handler );

		main.add( "Center", scPane );
		main.add( "South", btnPane );

		this.getContentPane().add( main );
		setVisible( true );
		this.setResizable( false );
	}// end HW5

	// display file dialog
	private File getFile()
	{
		JFileChooser fileChooser = new JFileChooser();
		fileChooser.setFileSelectionMode( JFileChooser.FILES_AND_DIRECTORIES );
		int result = fileChooser.showOpenDialog( this );
		if ( result == JFileChooser.CANCEL_OPTION )
			System.exit( 1 );
		File fileName = fileChooser.getSelectedFile();
		if ( ( fileName == null ) || ( fileName.getName().equals( "" ) ) )
		{
			JOptionPane.showMessageDialog( this, "Invalid File Name", "Invalid File Name",
				JOptionPane.ERROR_MESSAGE );
			System.exit( 1 );
		}
		return fileName;
	}// end getFile

	// open file and display contents in a JTextArea
	private void processFile( File name )
	{
		String directory[] = name.list();
		for ( String directoryName : directory )
		{
			String fName = directoryName;
			String newfName = changeExtension( fName, ".test" );

			File oldFile = new File(fName);
			File newFile = new File( newfName );
			outputArea.append( directoryName + "\n" );
			oldFile.renameTo( newFile );
			outputArea2.append( newfName + "\n" );
		}

	}// end processFile


	// Handler - determines what button was pressed
	private class Handler implements ActionListener
	{
		public void actionPerformed(ActionEvent ev)
		{
			if ( ev.getSource() == btn )
			{
				processFile( getFile() );
			}

		}// end actionPerformed
	}// end handler

//============================================== changeExtension
    // changes extension to new extension
    // example: x = changeExtension("data.txt", ".java")
    //         will assign "data.java" to x.
	private String changeExtension(String originalName, String newExtension)
	{
    	int lastDot = originalName.lastIndexOf(".");
    	if (lastDot != -1)
    	{
        	return originalName.substring(0, lastDot) + newExtension;
    	}
    	else
    	{
        return originalName + newExtension;
    	}
	}//end changeExtension


}

What's happening is, when I select a folder, everything looks like it ran okay, but the files don't change. I've tried testing for the newfName, and seen it's been changed correctly. Any ideas? Thanks.

 

[stefanwagner]

Everything looks ok, because you don't look at all:

 private void processFile (File name)
	{
		String directory [] = name.list ();
		for (String directoryName : directory)
		{
			String fName = directoryName;
			String newfName = changeExtension (fName, ".test");
			File oldFile = new File (fName);
			File newFile = new File (newfName);
			outputArea.append (directoryName + "\n");
			boolean ok = oldFile.renameTo (newFile);
			if (ok) outputArea2.append (newfName + "\t" + ok + "\n");
			else outputArea2.append ("failed: " + newfName + "\n");
		}
	}

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[kodr]

Thanks for the reply. Actually I had almost the same code in there before, but I've re-written that method so many times trying to get it to work that I left it out of the version I posted.

Any idea why I'm not able to rename the files in the directory that I choose? I created a folder called "Test Folder" in my root directory, and created three blank text files (1.txt , 2.txt, 3.txt ).

I did find that if I hard coded a file name "c:\\test.txt" I could rename it, but for some reason I can't get .renameTo to work with a file name coming from the chooser portion of my code.

 

[stefanwagner]

From javadocs, File:

list()
... Each string is a file name rather than a complete path.

So running your program in /home/kodr you choose a directory /home/kodr/test/ with a file foo.txt, the program will try to rename a file /home/kodr/foo.txt to whatsoever.

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http://home.arcor.de/hirnstrom/bewerbung

 

[kodr]

Thanks.

Here's what I ended up with:

private void processFile (File name)
    {
        String directory [] = name.list ();
        String path = name.getAbsolutePath();
        for (String directoryName : directory)
        {
            String fName = directoryName;
            String newfName = changeExtension (fName, ".test");
            File oldFile = new File ( path + "\\" + fName);
            File newFile = new File ( path + "\\" + newfName);
            outputArea.append (directoryName + "\n");
            boolean ok = oldFile.renameTo (newFile);
            if (ok) outputArea2.append (newfName + "\t" + ok + "\n");
            else outputArea2.append ("failed: " + newfName + "\n");
        }
    }

I had to add the path to both the original and new name, and that got everything working.