https://openjdk.java.net/ 
/*
 * Copyright (c) 1998, 2006, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

package javax.swing.filechooser;


import javax.swing.event.*;
import javax.swing.*;

import java.awt.Image;
import java.io.File;
import java.io.FileFilter;
import java.io.FilenameFilter;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.text.MessageFormat;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.Vector;
import java.beans.PropertyChangeListener;
import java.beans.PropertyChangeEvent;


import java.lang.reflect.*;

import sun.awt.shell.*;


FileSystemView is JFileChooser's gateway to the
file system. Since the JDK1.1 File API doesn't allow
access to such information as root partitions, file type
information, or hidden file bits, this class is designed
to intuit as much OS-specific file system information as
possible.


Java Licensees may want to provide a different implementation of
FileSystemView to better handle a given operating system.

Author:Jeff Dinkins
/**
 * FileSystemView is JFileChooser's gateway to the
 * file system. Since the JDK1.1 File API doesn't allow
 * access to such information as root partitions, file type
 * information, or hidden file bits, this class is designed
 * to intuit as much OS-specific file system information as
 * possible.
 *
 * <p>
 *
 * Java Licensees may want to provide a different implementation of
 * FileSystemView to better handle a given operating system.
 *
 * @author Jeff Dinkins
 */

// PENDING(jeff) - need to provide a specification for
// how Mac/OS2/BeOS/etc file systems can modify FileSystemView
// to handle their particular type of file system.

public abstract class FileSystemView {

    static FileSystemView windowsFileSystemView = null;
    static FileSystemView unixFileSystemView = null;
    //static FileSystemView macFileSystemView = null;
    static FileSystemView genericFileSystemView = null;
    static boolean useSystemExtensionsHiding = false;

    public static FileSystemView getFileSystemView() {
        useSystemExtensionsHiding = UIManager.getDefaults().getBoolean("FileChooser.useSystemExtensionHiding");
        UIManager.addPropertyChangeListener(new PropertyChangeListener() {
            public void propertyChange(PropertyChangeEvent e) {
               if (e.getPropertyName().equals("lookAndFeel")) {
                   useSystemExtensionsHiding = UIManager.getDefaults().getBoolean("FileChooser.useSystemExtensionHiding");
               }
            }
        });

        if(File.separatorChar == '\\') {
            if(windowsFileSystemView == null) {
                windowsFileSystemView = new WindowsFileSystemView();
            }
            return windowsFileSystemView;
        }

        if(File.separatorChar == '/') {
            if(unixFileSystemView == null) {
                unixFileSystemView = new UnixFileSystemView();
            }
            return unixFileSystemView;
        }

        // if(File.separatorChar == ':') {
        //    if(macFileSystemView == null) {
        //      macFileSystemView = new MacFileSystemView();
        //    }
        //    return macFileSystemView;
        //}

        if(genericFileSystemView == null) {
            genericFileSystemView = new GenericFileSystemView();
        }
        return genericFileSystemView;
    }

    
Determines if the given file is a root in the navigatable tree(s).
Examples: Windows 98 has one root, the Desktop folder. DOS has one root
per drive letter, C:\, D:\, etc. Unix has one root,
the "/" directory.
The default implementation gets information from the ShellFolder class.

Params:
  • f – a File object representing a directory
See Also:
Returns:true if f is a root in the navigatable tree.
/**
     * Determines if the given file is a root in the navigatable tree(s).
     * Examples: Windows 98 has one root, the Desktop folder. DOS has one root
     * per drive letter, <code>C:\</code>, <code>D:\</code>, etc. Unix has one root,
     * the <code>"/"</code> directory.
     *
     * The default implementation gets information from the <code>ShellFolder</code> class.
     *
     * @param f a <code>File</code> object representing a directory
     * @return <code>true</code> if <code>f</code> is a root in the navigatable tree.
     * @see #isFileSystemRoot
     */
    public boolean isRoot(File f) {
        if (f == null || !f.isAbsolute()) {
            return false;
        }

        File[] roots = getRoots();
        for (File root : roots) {
            if (root.equals(f)) {
                return true;
            }
        }
        return false;
    }

    
Returns true if the file (directory) can be visited.
Returns false if the directory cannot be traversed.

Params:
  • f – the File
See Also:
Returns:true if the file/directory can be traversed, otherwise false
Since:1.4
/**
     * Returns true if the file (directory) can be visited.
     * Returns false if the directory cannot be traversed.
     *
     * @param f the <code>File</code>
     * @return <code>true</code> if the file/directory can be traversed, otherwise <code>false</code>
     * @see JFileChooser#isTraversable
     * @see FileView#isTraversable
     * @since 1.4
     */
    public Boolean isTraversable(File f) {
        return Boolean.valueOf(f.isDirectory());
    }

    
Name of a file, directory, or folder as it would be displayed in
a system file browser. Example from Windows: the "M:\" directory
displays as "CD-ROM (M:)"
The default implementation gets information from the ShellFolder class.

Params:
  • f – a File object
See Also:
Returns:the file name as it would be displayed by a native file chooser
Since:1.4
/**
     * Name of a file, directory, or folder as it would be displayed in
     * a system file browser. Example from Windows: the "M:\" directory
     * displays as "CD-ROM (M:)"
     *
     * The default implementation gets information from the ShellFolder class.
     *
     * @param f a <code>File</code> object
     * @return the file name as it would be displayed by a native file chooser
     * @see JFileChooser#getName
     * @since 1.4
     */
    public String getSystemDisplayName(File f) {
        String name = null;
        if (f != null) {
            name = f.getName();
            if (!name.equals("..") && !name.equals(".") &&
                (useSystemExtensionsHiding ||
                 !isFileSystem(f) ||
                 isFileSystemRoot(f)) &&
                ((f instanceof ShellFolder) ||
                 f.exists())) {

                name = getShellFolder(f).getDisplayName();
                if (name == null || name.length() == 0) {
                    name = f.getPath(); // e.g. "/"
                }
            }
        }
        return name;
    }

    
Type description for a file, directory, or folder as it would be displayed in
a system file browser. Example from Windows: the "Desktop" folder
is desribed as "Desktop".
Override for platforms with native ShellFolder implementations.

Params:
  • f – a File object
See Also:
Returns:the file type description as it would be displayed by a native file chooser
or null if no native information is available.
Since:1.4
/**
     * Type description for a file, directory, or folder as it would be displayed in
     * a system file browser. Example from Windows: the "Desktop" folder
     * is desribed as "Desktop".
     *
     * Override for platforms with native ShellFolder implementations.
     *
     * @param f a <code>File</code> object
     * @return the file type description as it would be displayed by a native file chooser
     * or null if no native information is available.
     * @see JFileChooser#getTypeDescription
     * @since 1.4
     */
    public String getSystemTypeDescription(File f) {
        return null;
    }

    
Icon for a file, directory, or folder as it would be displayed in
a system file browser. Example from Windows: the "M:\" directory
displays a CD-ROM icon.
The default implementation gets information from the ShellFolder class.

Params:
  • f – a File object
See Also:
Returns:an icon as it would be displayed by a native file chooser
Since:1.4
/**
     * Icon for a file, directory, or folder as it would be displayed in
     * a system file browser. Example from Windows: the "M:\" directory
     * displays a CD-ROM icon.
     *
     * The default implementation gets information from the ShellFolder class.
     *
     * @param f a <code>File</code> object
     * @return an icon as it would be displayed by a native file chooser
     * @see JFileChooser#getIcon
     * @since 1.4
     */
    public Icon getSystemIcon(File f) {
        if (f != null) {
            ShellFolder sf = getShellFolder(f);
            Image img = sf.getIcon(false);
            if (img != null) {
                return new ImageIcon(img, sf.getFolderType());
            } else {
                return UIManager.getIcon(f.isDirectory() ? "FileView.directoryIcon" : "FileView.fileIcon");
            }
        } else {
            return null;
        }
    }

    
On Windows, a file can appear in multiple folders, other than its
parent directory in the filesystem. Folder could for example be the
"Desktop" folder which is not the same as file.getParentFile().

Params:
  • folder – a File object repesenting a directory or special folder
  • file – a File object
Returns:true if folder is a directory or special folder and contains file.
Since:1.4
/**
     * On Windows, a file can appear in multiple folders, other than its
     * parent directory in the filesystem. Folder could for example be the
     * "Desktop" folder which is not the same as file.getParentFile().
     *
     * @param folder a <code>File</code> object repesenting a directory or special folder
     * @param file a <code>File</code> object
     * @return <code>true</code> if <code>folder</code> is a directory or special folder and contains <code>file</code>.
     * @since 1.4
     */
    public boolean isParent(File folder, File file) {
        if (folder == null || file == null) {
            return false;
        } else if (folder instanceof ShellFolder) {
                File parent = file.getParentFile();
                if (parent != null && parent.equals(folder)) {
                    return true;
                }
            File[] children = getFiles(folder, false);
            for (File child : children) {
                if (file.equals(child)) {
                    return true;
                }
            }
            return false;
        } else {
            return folder.equals(file.getParentFile());
        }
    }

    
Params:
  • parent – a File object repesenting a directory or special folder
  • fileName – a name of a file or folder which exists in parent
Returns:a File object. This is normally constructed with new
File(parent, fileName) except when parent and child are both
special folders, in which case the File is a wrapper containing
a ShellFolder object.
Since:1.4
/**
     *
     * @param parent a <code>File</code> object repesenting a directory or special folder
     * @param fileName a name of a file or folder which exists in <code>parent</code>
     * @return a File object. This is normally constructed with <code>new
     * File(parent, fileName)</code> except when parent and child are both
     * special folders, in which case the <code>File</code> is a wrapper containing
     * a <code>ShellFolder</code> object.
     * @since 1.4
     */
    public File getChild(File parent, String fileName) {
        if (parent instanceof ShellFolder) {
            File[] children = getFiles(parent, false);
            for (File child : children) {
                if (child.getName().equals(fileName)) {
                    return child;
                }
            }
        }
        return createFileObject(parent, fileName);
    }


    
Checks if f represents a real directory or file as opposed to a
special folder such as "Desktop". Used by UI classes to decide if
a folder is selectable when doing directory choosing.

Params:
  • f – a File object
Returns:true if f is a real file or directory.
Since:1.4
/**
     * Checks if <code>f</code> represents a real directory or file as opposed to a
     * special folder such as <code>"Desktop"</code>. Used by UI classes to decide if
     * a folder is selectable when doing directory choosing.
     *
     * @param f a <code>File</code> object
     * @return <code>true</code> if <code>f</code> is a real file or directory.
     * @since 1.4
     */
    public boolean isFileSystem(File f) {
        if (f instanceof ShellFolder) {
            ShellFolder sf = (ShellFolder)f;
            // Shortcuts to directories are treated as not being file system objects,
            // so that they are never returned by JFileChooser.
            return sf.isFileSystem() && !(sf.isLink() && sf.isDirectory());
        } else {
            return true;
        }
    }

    
Creates a new folder with a default folder name.

/**
     * Creates a new folder with a default folder name.
     */
    public abstract File createNewFolder(File containingDir) throws IOException;

    
Returns whether a file is hidden or not.

/**
     * Returns whether a file is hidden or not.
     */
    public boolean isHiddenFile(File f) {
        return f.isHidden();
    }


    
Is dir the root of a tree in the file system, such as a drive
or partition. Example: Returns true for "C:\" on Windows 98.

Params:
  • dir – a File object representing a directory
See Also:
Returns:true if f is a root of a filesystem
Since:1.4
/**
     * Is dir the root of a tree in the file system, such as a drive
     * or partition. Example: Returns true for "C:\" on Windows 98.
     *
     * @param dir a <code>File</code> object representing a directory
     * @return <code>true</code> if <code>f</code> is a root of a filesystem
     * @see #isRoot
     * @since 1.4
     */
    public boolean isFileSystemRoot(File dir) {
        return ShellFolder.isFileSystemRoot(dir);
    }

    
Used by UI classes to decide whether to display a special icon
for drives or partitions, e.g. a "hard disk" icon.
The default implementation has no way of knowing, so always returns false.

Params:
  • dir – a directory
Returns:false always
Since:1.4
/**
     * Used by UI classes to decide whether to display a special icon
     * for drives or partitions, e.g. a "hard disk" icon.
     *
     * The default implementation has no way of knowing, so always returns false.
     *
     * @param dir a directory
     * @return <code>false</code> always
     * @since 1.4
     */
    public boolean isDrive(File dir) {
        return false;
    }

    
Used by UI classes to decide whether to display a special icon
for a floppy disk. Implies isDrive(dir).
The default implementation has no way of knowing, so always returns false.

Params:
  • dir – a directory
Returns:false always
Since:1.4
/**
     * Used by UI classes to decide whether to display a special icon
     * for a floppy disk. Implies isDrive(dir).
     *
     * The default implementation has no way of knowing, so always returns false.
     *
     * @param dir a directory
     * @return <code>false</code> always
     * @since 1.4
     */
    public boolean isFloppyDrive(File dir) {
        return false;
    }

    
Used by UI classes to decide whether to display a special icon
for a computer node, e.g. "My Computer" or a network server.
The default implementation has no way of knowing, so always returns false.

Params:
  • dir – a directory
Returns:false always
Since:1.4
/**
     * Used by UI classes to decide whether to display a special icon
     * for a computer node, e.g. "My Computer" or a network server.
     *
     * The default implementation has no way of knowing, so always returns false.
     *
     * @param dir a directory
     * @return <code>false</code> always
     * @since 1.4
     */
    public boolean isComputerNode(File dir) {
        return ShellFolder.isComputerNode(dir);
    }


    
Returns all root partitions on this system. For example, on
Windows, this would be the "Desktop" folder, while on DOS this
would be the A: through Z: drives.

/**
     * Returns all root partitions on this system. For example, on
     * Windows, this would be the "Desktop" folder, while on DOS this
     * would be the A: through Z: drives.
     */
    public File[] getRoots() {
        // Don't cache this array, because filesystem might change
        File[] roots = (File[])ShellFolder.get("roots");

        for (int i = 0; i < roots.length; i++) {
            if (isFileSystemRoot(roots[i])) {
                roots[i] = createFileSystemRoot(roots[i]);
            }
        }
        return roots;
    }


    // Providing default implementations for the remaining methods
    // because most OS file systems will likely be able to use this
    // code. If a given OS can't, override these methods in its
    // implementation.

    public File getHomeDirectory() {
        return createFileObject(System.getProperty("user.home"));
    }

    
Return the user's default starting directory for the file chooser.

Returns:a File object representing the default
        starting folder
Since:1.4
/**
     * Return the user's default starting directory for the file chooser.
     *
     * @return a <code>File</code> object representing the default
     *         starting folder
     * @since 1.4
     */
    public File getDefaultDirectory() {
        File f = (File)ShellFolder.get("fileChooserDefaultFolder");
        if (isFileSystemRoot(f)) {
            f = createFileSystemRoot(f);
        }
        return f;
    }

    
Returns a File object constructed in dir from the given filename.

/**
     * Returns a File object constructed in dir from the given filename.
     */
    public File createFileObject(File dir, String filename) {
        if(dir == null) {
            return new File(filename);
        } else {
            return new File(dir, filename);
        }
    }

    
Returns a File object constructed from the given path string.

/**
     * Returns a File object constructed from the given path string.
     */
    public File createFileObject(String path) {
        File f = new File(path);
        if (isFileSystemRoot(f)) {
            f = createFileSystemRoot(f);
        }
        return f;
    }


    
Gets the list of shown (i.e. not hidden) files.

/**
     * Gets the list of shown (i.e. not hidden) files.
     */
    public File[] getFiles(File dir, boolean useFileHiding) {
        Vector<File> files = new Vector<File>();


        // add all files in dir
        File[] names;
            if (!(dir instanceof ShellFolder)) {
                dir = getShellFolder(dir);
            }

            names = ((ShellFolder)dir).listFiles(!useFileHiding);
        File f;

        int nameCount = (names == null) ? 0 : names.length;
        for (int i = 0; i < nameCount; i++) {
            if (Thread.currentThread().isInterrupted()) {
                break;
            }
            f = names[i];
            if (!(f instanceof ShellFolder)) {
                if (isFileSystemRoot(f)) {
                    f = createFileSystemRoot(f);
                }
                try {
                    f = ShellFolder.getShellFolder(f);
                } catch (FileNotFoundException e) {
                    // Not a valid file (wouldn't show in native file chooser)
                    // Example: C:\pagefile.sys
                    continue;
                } catch (InternalError e) {
                    // Not a valid file (wouldn't show in native file chooser)
                    // Example C:\Winnt\Profiles\joe\history\History.IE5
                    continue;
                }
            }
            if (!useFileHiding || !isHiddenFile(f)) {
                files.addElement(f);
            }
        }

        return files.toArray(new File[files.size()]);
    }



    
Returns the parent directory of dir.

Params:
  • dir – the File being queried
Returns:the parent directory of dir, or
  null if dir is null
/**
     * Returns the parent directory of <code>dir</code>.
     * @param dir the <code>File</code> being queried
     * @return the parent directory of <code>dir</code>, or
     *   <code>null</code> if <code>dir</code> is <code>null</code>
     */
    public File getParentDirectory(File dir) {
        if (dir != null && dir.exists()) {
            ShellFolder sf = getShellFolder(dir);
            File psf = sf.getParentFile();
            if (psf != null) {
                if (isFileSystem(psf)) {
                    File f = psf;
                    if (f != null && !f.exists()) {
                        // This could be a node under "Network Neighborhood".
                        File ppsf = psf.getParentFile();
                        if (ppsf == null || !isFileSystem(ppsf)) {
                            // We're mostly after the exists() override for windows below.
                            f = createFileSystemRoot(f);
                        }
                    }
                    return f;
                } else {
                    return psf;
                }
            }
        }
        return null;
    }

    ShellFolder getShellFolder(File f) {
        if (!(f instanceof ShellFolder)
            && !(f instanceof FileSystemRoot)
            && isFileSystemRoot(f)) {

            f = createFileSystemRoot(f);
        }
        try {
            return ShellFolder.getShellFolder(f);
        } catch (FileNotFoundException e) {
            System.err.println("FileSystemView.getShellFolder: f="+f);
            e.printStackTrace();
            return null;
        } catch (InternalError e) {
            System.err.println("FileSystemView.getShellFolder: f="+f);
            e.printStackTrace();
            return null;
        }
    }

    
Creates a new File object for f with correct
behavior for a file system root directory.

Params:
  • f – a File object representing a file system root
         directory, for example "/" on Unix or "C:\" on Windows.
Returns:a new File object
Since:1.4
/**
     * Creates a new <code>File</code> object for <code>f</code> with correct
     * behavior for a file system root directory.
     *
     * @param f a <code>File</code> object representing a file system root
     *          directory, for example "/" on Unix or "C:\" on Windows.
     * @return a new <code>File</code> object
     * @since 1.4
     */
    protected File createFileSystemRoot(File f) {
        return new FileSystemRoot(f);
    }




    static class FileSystemRoot extends File {
        public FileSystemRoot(File f) {
            super(f,"");
        }

        public FileSystemRoot(String s) {
            super(s);
        }

        public boolean isDirectory() {
            return true;
        }

        public String getName() {
            return getPath();
        }
    }
}


FileSystemView that handles some specific unix-isms.

/**
 * FileSystemView that handles some specific unix-isms.
 */
class UnixFileSystemView extends FileSystemView {

    private static final String newFolderString =
            UIManager.getString("FileChooser.other.newFolder");
    private static final String newFolderNextString  =
            UIManager.getString("FileChooser.other.newFolder.subsequent");

    
Creates a new folder with a default folder name.

/**
     * Creates a new folder with a default folder name.
     */
    public File createNewFolder(File containingDir) throws IOException {
        if(containingDir == null) {
            throw new IOException("Containing directory is null:");
        }
        File newFolder;
        // Unix - using OpenWindows' default folder name. Can't find one for Motif/CDE.
        newFolder = createFileObject(containingDir, newFolderString);
        int i = 1;
        while (newFolder.exists() && (i < 100)) {
            newFolder = createFileObject(containingDir, MessageFormat.format(
                    newFolderNextString, new Object[] { new Integer(i) }));
            i++;
        }

        if(newFolder.exists()) {
            throw new IOException("Directory already exists:" + newFolder.getAbsolutePath());
        } else {
            newFolder.mkdirs();
        }

        return newFolder;
    }

    public boolean isFileSystemRoot(File dir) {
        return (dir != null && dir.getAbsolutePath().equals("/"));
    }

    public boolean isDrive(File dir) {
        return isFloppyDrive(dir);
    }

    public boolean isFloppyDrive(File dir) {
        // Could be looking at the path for Solaris, but wouldn't be reliable.
        // For example:
        // return (dir != null && dir.getAbsolutePath().toLowerCase().startsWith("/floppy"));
        return false;
    }

    public boolean isComputerNode(File dir) {
        if (dir != null) {
            String parent = dir.getParent();
            if (parent != null && parent.equals("/net")) {
                return true;
            }
        }
        return false;
    }
}



FileSystemView that handles some specific windows concepts.

/**
 * FileSystemView that handles some specific windows concepts.
 */
class WindowsFileSystemView extends FileSystemView {

    private static final String newFolderString =
            UIManager.getString("FileChooser.win32.newFolder");
    private static final String newFolderNextString  =
            UIManager.getString("FileChooser.win32.newFolder.subsequent");

    public Boolean isTraversable(File f) {
        return Boolean.valueOf(isFileSystemRoot(f) || isComputerNode(f) || f.isDirectory());
    }

    public File getChild(File parent, String fileName) {
        if (fileName.startsWith("\\")
            && !(fileName.startsWith("\\\\"))
            && isFileSystem(parent)) {

            //Path is relative to the root of parent's drive
            String path = parent.getAbsolutePath();
            if (path.length() >= 2
                && path.charAt(1) == ':'
                && Character.isLetter(path.charAt(0))) {

                return createFileObject(path.substring(0, 2) + fileName);
            }
        }
        return super.getChild(parent, fileName);
    }

    
Type description for a file, directory, or folder as it would be displayed in
a system file browser. Example from Windows: the "Desktop" folder
is desribed as "Desktop".
The Windows implementation gets information from the ShellFolder class.

/**
     * Type description for a file, directory, or folder as it would be displayed in
     * a system file browser. Example from Windows: the "Desktop" folder
     * is desribed as "Desktop".
     *
     * The Windows implementation gets information from the ShellFolder class.
     */
    public String getSystemTypeDescription(File f) {
        if (f != null) {
            return getShellFolder(f).getFolderType();
        } else {
            return null;
        }
    }

    
Returns:the Desktop folder.
/**
     * @return the Desktop folder.
     */
    public File getHomeDirectory() {
        File[] roots = getRoots();
        return (roots.length == 0) ? null : roots[0];
    }

    
Creates a new folder with a default folder name.

/**
     * Creates a new folder with a default folder name.
     */
    public File createNewFolder(File containingDir) throws IOException {
        if(containingDir == null) {
            throw new IOException("Containing directory is null:");
        }
        // Using NT's default folder name
        File newFolder = createFileObject(containingDir, newFolderString);
        int i = 2;
        while (newFolder.exists() && (i < 100)) {
            newFolder = createFileObject(containingDir, MessageFormat.format(
                newFolderNextString, new Object[] { new Integer(i) }));
            i++;
        }

        if(newFolder.exists()) {
            throw new IOException("Directory already exists:" + newFolder.getAbsolutePath());
        } else {
            newFolder.mkdirs();
        }

        return newFolder;
    }

    public boolean isDrive(File dir) {
        return isFileSystemRoot(dir);
    }

    public boolean isFloppyDrive(File dir) {
        String path = dir.getAbsolutePath();
        return (path != null && (path.equals("A:\\") || path.equals("B:\\")));
    }

    
Returns a File object constructed from the given path string.

/**
     * Returns a File object constructed from the given path string.
     */
    public File createFileObject(String path) {
        // Check for missing backslash after drive letter such as "C:" or "C:filename"
        if (path.length() >= 2 && path.charAt(1) == ':' && Character.isLetter(path.charAt(0))) {
            if (path.length() == 2) {
                path += "\\";
            } else if (path.charAt(2) != '\\') {
                path = path.substring(0, 2) + "\\" + path.substring(2);
            }
        }
        return super.createFileObject(path);
    }

    protected File createFileSystemRoot(File f) {
        // Problem: Removable drives on Windows return false on f.exists()
        // Workaround: Override exists() to always return true.
        return new FileSystemRoot(f) {
            public boolean exists() {
                return true;
            }
        };
    }

}


Fallthrough FileSystemView in case we can't determine the OS.

/**
 * Fallthrough FileSystemView in case we can't determine the OS.
 */
class GenericFileSystemView extends FileSystemView {

    private static final String newFolderString =
            UIManager.getString("FileChooser.other.newFolder");

    
Creates a new folder with a default folder name.

/**
     * Creates a new folder with a default folder name.
     */
    public File createNewFolder(File containingDir) throws IOException {
        if(containingDir == null) {
            throw new IOException("Containing directory is null:");
        }
        // Using NT's default folder name
        File newFolder = createFileObject(containingDir, newFolderString);

        if(newFolder.exists()) {
            throw new IOException("Directory already exists:" + newFolder.getAbsolutePath());
        } else {
            newFolder.mkdirs();
        }

        return newFolder;
    }

}