JFileChooser - only make certain directories selectable

Question

I would like the user to be able to view all directories but only be able to choose ones that contain a certain file.
For example, most IDE's allow you to only select directories that cantain project file (they even manage to give project directories different icons).
HOW?
Here is what I have got so for...
private void openProjectMenuItemActionPerformed(java.awt.event.ActionEvent evt)
            System.out.println("open project");
            JFileChooser jfc = new JFileChooser();
            jfc.setFileSelectionMode(JFileChooser.DIRECTORIES_ONLY);
            jfc.addChoosableFileFilter(new javax.swing.filechooser.FileFilter()
                @Override
                public boolean accept(File f)
                    if(!f.isDirectory())
                        return false;
                    for(File file:f.listFiles())
                        if((file.getName().toLowerCase()).endsWith("jan"));
                            return true;
                    return false;
                @Override
                public String getDescription()
                    return "Return JAnnotate folders";
            if(jfc.showOpenDialog(this)==JFileChooser.APPROVE_OPTION)
                System.out.println(jfc.getSelectedFile().getName());
    }

Answer 1

Thanks for your help.
This seems to work a little better for me but its still doesn't feel like the best solution.
import javax.swing.JFileChooser;
import utilities.MyFileChooser;
public class FileFilterEg {
    public static void main(String[] args)
        JFileChooser jfc = new MyFileChooser();
        jfc.setFileSelectionMode(JFileChooser.DIRECTORIES_ONLY);
        if(jfc.showOpenDialog(null) == JFileChooser.APPROVE_OPTION)
            System.out.println(jfc.getSelectedFile().getName());
package utilities;
import java.io.File;
import javax.swing.Icon;
import javax.swing.JFileChooser;
import javax.swing.filechooser.FileView;
public class MyFileChooser extends JFileChooser
    public MyFileChooser()
        setFileView(new FileView()
            @Override
            public Icon getIcon(File f)
                if(fileSelectable(f))
                    return new javax.swing.ImageIcon(getClass().getResource("/images/janicon.png"));
                return super.getIcon(f);
    @Override
    public void approveSelection()
        File f=getSelectedFile();
        if(fileSelectable(f))
            super.approveSelection();
        else
            if(f.isDirectory())
                this.setCurrentDirectory(f);
    private boolean fileSelectable(File f)
        if(!f.isDirectory())
            return false;
        try
            for(String fileName:f.list())
                if((fileName.toLowerCase()).endsWith(".jan"))
                    return true;
        catch(NullPointerException e)// sometimes a NullPointerException is thrown.  Can't work out why.
            System.err.println("====================");
            System.err.println(e.getMessage());
            System.err.println("====================");
        return false;
}