JDK8/Java8源码在线阅读
/*
* Copyright (c) 1998, 2013, 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
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package javax.swing.filechooser;
import javax.swing.*;
import java.awt.Image;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.text.MessageFormat;
import java.util.List;
import java.util.ArrayList;
import java.lang.ref.WeakReference;
import java.beans.PropertyChangeListener;
import java.beans.PropertyChangeEvent;
import java.security.AccessController;
import java.security.PrivilegedAction;
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.
*
* <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;
private boolean useSystemExtensionHiding =
UIManager.getDefaults().getBoolean("FileChooser.useSystemExtensionHiding");
public static FileSystemView getFileSystemView() {
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;
}
public FileSystemView() {
final WeakReference<FileSystemView> weakReference = new WeakReference<FileSystemView>(this);
UIManager.addPropertyChangeListener(new PropertyChangeListener() {
public void propertyChange(PropertyChangeEvent evt) {
FileSystemView fileSystemView = weakReference.get();
if (fileSystemView == null) {
// FileSystemView was destroyed
UIManager.removePropertyChangeListener(this);
} else {
if (evt.getPropertyName().equals("lookAndFeel")) {
fileSystemView.useSystemExtensionHiding =
UIManager.getDefaults().getBoolean("FileChooser.useSystemExtensionHiding");
}
}
}
});
}
/**
* Determines if the given file is a root in the navigable 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 navigable 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.
*
* @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.
*
* @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) {
if (f == null) {
return null;
}
String name = f.getName();
if (!name.equals("..") && !name.equals(".") &&
(useSystemExtensionHiding || !isFileSystem(f) || isFileSystemRoot(f)) &&
(f instanceof ShellFolder || f.exists())) {
try {
name = getShellFolder(f).getDisplayName();
} catch (FileNotFoundException e) {
return null;
}
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 described 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.
*
* @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) {
return null;
}
ShellFolder sf;
try {
sf = getShellFolder(f);
} catch (FileNotFoundException e) {
return null;
}
Image img = sf.getIcon(false);
if (img != null) {
return new ImageIcon(img, sf.getFolderType());
} else {
return UIManager.getIcon(f.isDirectory() ? "FileView.directoryIcon" : "FileView.fileIcon");
}
}
/**
* 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 representing 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());
}
}
/**
*
* @param parent a <code>File</code> object representing 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 <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.
*/
public abstract File createNewFolder(File containingDir) throws IOException;
/**
* 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.
*
* @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.
*
* @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.
*
* @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.
*
* @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.
*/
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.
*
* @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.
*/
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.
*/
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.
*/
public File[] getFiles(File dir, boolean useFileHiding) {
List<File> files = new ArrayList<File>();
// add all files in dir
if (!(dir instanceof ShellFolder)) {
try {
dir = getShellFolder(dir);
} catch (FileNotFoundException e) {
return new File[0];
}
}
File[] names = ((ShellFolder) dir).listFiles(!useFileHiding);
if (names == null) {
return new File[0];
}
for (File f : names) {
if (Thread.currentThread().isInterrupted()) {
break;
}
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.add(f);
}
}
return files.toArray(new File[files.size()]);
}
/**
* 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()) {
return null;
}
ShellFolder sf;
try {
sf = getShellFolder(dir);
} catch (FileNotFoundException e) {
return null;
}
File psf = sf.getParentFile();
if (psf == null) {
return null;
}
if (isFileSystem(psf)) {
File f = psf;
if (!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;
}
}
/**
* Throws {@code FileNotFoundException} if file not found or current thread was interrupted
*/
ShellFolder getShellFolder(File f) throws FileNotFoundException {
if (!(f instanceof ShellFolder) && !(f instanceof FileSystemRoot) && isFileSystemRoot(f)) {
f = createFileSystemRoot(f);
}
try {
return ShellFolder.getShellFolder(f);
} catch (InternalError e) {
System.err.println("FileSystemView.getShellFolder: f="+f);
e.printStackTrace();
return null;
}
}
/**
* 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.
*/
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.
*/
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 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.
*/
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 described as "Desktop".
*
* The Windows implementation gets information from the ShellFolder class.
*/
public String getSystemTypeDescription(File f) {
if (f == null) {
return null;
}
try {
return getShellFolder(f).getFolderType();
} catch (FileNotFoundException e) {
return null;
}
}
/**
* @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.
*/
public File createNewFolder(File containingDir) throws IOException {
if(containingDir == null) {
throw new IOException("Containing directory is null:");
}
// Using NT's default folder name
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