Class Desktop

public class Desktop
extends Object

The Desktop class allows interact with various desktop capabilities.

Supported operations include:

  • launching the user-default browser to show a specified URI;
  • launching the user-default mail client with an optional mailto URI;
  • launching a registered application to open, edit or print a specified file.

This class provides methods corresponding to these operations. The methods look for the associated application registered on the current platform, and launch it to handle a URI or file. If there is no associated application or the associated application fails to be launched, an exception is thrown. Please see Desktop.Action for the full list of supported operations and capabilities.

An application is registered to a URI or file type. The mechanism of registering, accessing, and launching the associated application is platform-dependent.

Each operation is an action type represented by the Desktop.Action class.

Note: when some action is invoked and the associated application is executed, it will be executed on the same system as the one on which the Java application was launched.

Since:
1.6
See Also:
Desktop.Action

Nested Class Summary

Nested Classes
Modifier and Type Class Description
static class  Desktop.Action

Represents an action type.

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type Method Description
void addAppEventListener​(SystemEventListener listener)

Adds sub-types of SystemEventListener to listen for notifications from the native system.
void browse​(URI uri)

Launches the default browser to display a URI.
void browseFileDirectory​(File file)

Opens a folder containing the file and selects it in a default system file manager.
void disableSuddenTermination()

Prevents this application from being suddenly terminated.
void edit​(File file)

Launches the associated editor application and opens a file for editing.
void enableSuddenTermination()

Enables this application to be suddenly terminated.
static Desktop getDesktop()

Returns the Desktop instance of the current desktop context.
static boolean isDesktopSupported()

Tests whether this class is supported on the current platform.
boolean isSupported​(Desktop.Action action)

Tests whether an action is supported on the current platform.
void mail()

Launches the mail composing window of the user default mail client.
void mail​(URI mailtoURI)

Launches the mail composing window of the user default mail client, filling the message fields specified by a mailto: URI.
boolean moveToTrash​(File file)

Moves the specified file to the trash.
void open​(File file)

Launches the associated application to open the file.
void openHelpViewer()

Opens the native help viewer application.
void print​(File file)

Prints a file with the native desktop printing facility, using the associated application's print command.
void removeAppEventListener​(SystemEventListener listener)

Removes sub-types of SystemEventListener to listen for notifications from the native system.
void requestForeground​(boolean allWindows)

Requests this application to move to the foreground.
void setAboutHandler​(AboutHandler aboutHandler)

Installs a handler to show a custom About window for your application.
void setDefaultMenuBar​(JMenuBar menuBar)

Sets the default menu bar to use when there are no active frames.
void setOpenFileHandler​(OpenFilesHandler openFileHandler)

Installs the handler which is notified when the application is asked to open a list of files.
void setOpenURIHandler​(OpenURIHandler openURIHandler)

Installs the handler which is notified when the application is asked to open a URL.
void setPreferencesHandler​(PreferencesHandler preferencesHandler)

Installs a handler to show a custom Preferences window for your application.
void setPrintFileHandler​(PrintFilesHandler printFileHandler)

Installs the handler which is notified when the application is asked to print a list of files.
void setQuitHandler​(QuitHandler quitHandler)

Installs the handler which determines if the application should quit.
void setQuitStrategy​(QuitStrategy strategy)

Sets the default strategy used to quit this application.

Methods declared in class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

getDesktop

public static Desktop getDesktop()

Returns the Desktop instance of the current desktop context. On some platforms the Desktop API may not be supported; use the isDesktopSupported() method to determine if the current desktop is supported.

Returns:
the Desktop instance
Throws:
HeadlessException - if GraphicsEnvironment.isHeadless() returns true
UnsupportedOperationException - if this class is not supported on the current platform
See Also:
isDesktopSupported(), GraphicsEnvironment.isHeadless()

isDesktopSupported

public static boolean isDesktopSupported()

Tests whether this class is supported on the current platform. If it's supported, use getDesktop() to retrieve an instance.

Returns:
true if this class is supported on the current platform; false otherwise
See Also:
getDesktop()

isSupported

public boolean isSupported​(Desktop.Action action)

Tests whether an action is supported on the current platform.

Even when the platform supports an action, a file or URI may not have a registered application for the action. For example, most of the platforms support the Desktop.Action.OPEN action. But for a specific file, there may not be an application registered to open it. In this case, isSupported(Action) may return true, but the corresponding action method will throw an IOException.

Parameters:
action - the specified Desktop.Action
Returns:
true if the specified action is supported on the current platform; false otherwise
See Also:
Desktop.Action

open

public void open​(File file)
          throws IOException

Launches the associated application to open the file.

If the specified file is a directory, the file manager of the current platform is launched to open it.

Parameters:
file - the file to be opened with the associated application
Throws:
NullPointerException - if file is null
IllegalArgumentException - if the specified file doesn't exist
UnsupportedOperationException - if the current platform does not support the Desktop.Action.OPEN action
IOException - if the specified file has no associated application or the associated application fails to be launched
SecurityException - if a security manager exists and its SecurityManager.checkRead(java.lang.String) method denies read access to the file, or it denies the AWTPermission("showWindowWithoutWarningBanner") permission, or the calling thread is not allowed to create a subprocess
See Also:
AWTPermission

edit

public void edit​(File file)
          throws IOException

Launches the associated editor application and opens a file for editing.

Parameters:
file - the file to be opened for editing
Throws:
NullPointerException - if the specified file is null
IllegalArgumentException - if the specified file doesn't exist
UnsupportedOperationException - if the current platform does not support the Desktop.Action.EDIT action
IOException - if the specified file has no associated editor, or the associated application fails to be launched
SecurityException - if a security manager exists and its SecurityManager.checkRead(java.lang.String) method denies read access to the file, or SecurityManager.checkWrite(java.lang.String) method denies write access to the file, or it denies the AWTPermission("showWindowWithoutWarningBanner") permission, or the calling thread is not allowed to create a subprocess
See Also:
AWTPermission

print

public void print​(File file)
           throws IOException

Prints a file with the native desktop printing facility, using the associated application's print command.

Parameters:
file - the file to be printed
Throws:
NullPointerException - if the specified file is null
IllegalArgumentException - if the specified file doesn't exist
UnsupportedOperationException - if the current platform does not support the Desktop.Action.PRINT action
IOException - if the specified file has no associated application that can be used to print it
SecurityException - if a security manager exists and its SecurityManager.checkRead(java.lang.String) method denies read access to the file, or its SecurityManager.checkPrintJobAccess() method denies the permission to print the file, or the calling thread is not allowed to create a subprocess

browse

public void browse​(URI uri)
            throws IOException

Launches the default browser to display a URI. If the default browser is not able to handle the specified URI, the application registered for handling URIs of the specified type is invoked. The application is determined from the protocol and path of the URI, as defined by the URI class.

Parameters:
uri - the URI to be displayed in the user default browser
Throws:
NullPointerException - if uri is null
UnsupportedOperationException - if the current platform does not support the Desktop.Action.BROWSE action
IOException - if the user default browser is not found, or it fails to be launched, or the default handler application failed to be launched
SecurityException - if a security manager exists and it denies the AWTPermission("showWindowWithoutWarningBanner") permission, or the calling thread is not allowed to create a subprocess
See Also:
URI, AWTPermission

mail

public void mail()
          throws IOException

Launches the mail composing window of the user default mail client.

Throws:
UnsupportedOperationException - if the current platform does not support the Desktop.Action.MAIL action
IOException - if the user default mail client is not found, or it fails to be launched
SecurityException - if a security manager exists and it denies the AWTPermission("showWindowWithoutWarningBanner") permission, or the calling thread is not allowed to create a subprocess
See Also:
AWTPermission

mail

public void mail​(URI mailtoURI)
          throws IOException

Launches the mail composing window of the user default mail client, filling the message fields specified by a mailto: URI.

A mailto: URI can specify message fields including "to", "cc", "subject", "body", etc. See The mailto URL scheme (RFC 2368) for the mailto: URI specification details.

Parameters:
mailtoURI - the specified mailto: URI
Throws:
NullPointerException - if the specified URI is null
IllegalArgumentException - if the URI scheme is not "mailto"
UnsupportedOperationException - if the current platform does not support the Desktop.Action.MAIL action
IOException - if the user default mail client is not found or fails to be launched
SecurityException - if a security manager exists and it denies the AWTPermission("showWindowWithoutWarningBanner") permission, or the calling thread is not allowed to create a subprocess
See Also:
URI, AWTPermission

addAppEventListener

public void addAppEventListener​(SystemEventListener listener)

Adds sub-types of SystemEventListener to listen for notifications from the native system. Has no effect if SystemEventListener's sub-type is unsupported on the current platform.

Parameters:
listener - listener
Throws:
SecurityException - if a security manager exists and it denies the RuntimePermission("canProcessApplicationEvents") permission
Since:
9
See Also:
AppForegroundListener, AppHiddenListener, AppReopenedListener, ScreenSleepListener, SystemSleepListener, UserSessionListener

removeAppEventListener

public void removeAppEventListener​(SystemEventListener listener)

Removes sub-types of SystemEventListener to listen for notifications from the native system. Has no effect if SystemEventListener's sub-type is unsupported on the current platform.

Parameters:
listener - listener
Throws:
SecurityException - if a security manager exists and it denies the RuntimePermission("canProcessApplicationEvents") permission
Since:
9
See Also:
AppForegroundListener, AppHiddenListener, AppReopenedListener, ScreenSleepListener, SystemSleepListener, UserSessionListener

setAboutHandler

public void setAboutHandler​(AboutHandler aboutHandler)

Installs a handler to show a custom About window for your application.

Setting the AboutHandler to null reverts it to the default behavior.

Parameters:
aboutHandler - the handler to respond to the AboutHandler.handleAbout(AboutEvent) message
Throws:
SecurityException - if a security manager exists and it denies the RuntimePermission("canProcessApplicationEvents") permission
UnsupportedOperationException - if the current platform does not support the Desktop.Action.APP_ABOUT action
Since:
9

setPreferencesHandler

public void setPreferencesHandler​(PreferencesHandler preferencesHandler)

Installs a handler to show a custom Preferences window for your application.

Setting the PreferencesHandler to null reverts it to the default behavior

Parameters:
preferencesHandler - the handler to respond to the PreferencesHandler.handlePreferences(PreferencesEvent)
Throws:
SecurityException - if a security manager exists and it denies the RuntimePermission("canProcessApplicationEvents") permission
UnsupportedOperationException - if the current platform does not support the Desktop.Action.APP_PREFERENCES action
Since:
9

setOpenFileHandler

public void setOpenFileHandler​(OpenFilesHandler openFileHandler)

Installs the handler which is notified when the application is asked to open a list of files.

Implementation Note:
Please note that for macOS, notifications are only sent if the Java app is a bundled application, with a CFBundleDocumentTypes array present in its Info.plist. Check the Apple Developer Documentation for more information about Info.plist.
Parameters:
openFileHandler - handler
Throws:
SecurityException - if a security manager exists and its SecurityManager.checkRead(java.lang.String) method denies read access to the files, or it denies the RuntimePermission("canProcessApplicationEvents") permission, or the calling thread is not allowed to create a subprocess
UnsupportedOperationException - if the current platform does not support the Desktop.Action.APP_OPEN_FILE action
Since:
9

setPrintFileHandler

public void setPrintFileHandler​(PrintFilesHandler printFileHandler)

Installs the handler which is notified when the application is asked to print a list of files.

Implementation Note:
Please note that for macOS, notifications are only sent if the Java app is a bundled application, with a CFBundleDocumentTypes array present in its Info.plist. Check the Apple Developer Documentation for more information about Info.plist.
Parameters:
printFileHandler - handler
Throws:
SecurityException - if a security manager exists and its SecurityManager.checkPrintJobAccess() method denies the permission to print or it denies the RuntimePermission("canProcessApplicationEvents") permission
UnsupportedOperationException - if the current platform does not support the Desktop.Action.APP_PRINT_FILE action
Since:
9

setOpenURIHandler

public void setOpenURIHandler​(OpenURIHandler openURIHandler)

Installs the handler which is notified when the application is asked to open a URL. Setting the handler to null causes all OpenURIHandler.openURI(OpenURIEvent) requests to be enqueued until another handler is set.

Implementation Note:
Please note that for macOS, notifications are only sent if the Java app is a bundled application, with a CFBundleDocumentTypes array present in its Info.plist. Check the Apple Developer Documentation for more information about Info.plist.
Parameters:
openURIHandler - handler RuntimePermission("canProcessApplicationEvents") permission, or the calling thread is not allowed to create a subprocess
Throws:
UnsupportedOperationException - if the current platform does not support the Desktop.Action.APP_OPEN_URI action
Since:
9

setQuitHandler

public void setQuitHandler​(QuitHandler quitHandler)

Installs the handler which determines if the application should quit. The handler is passed a one-shot QuitResponse which can cancel or proceed with the quit. Setting the handler to null causes all quit requests to directly perform the default QuitStrategy.

Parameters:
quitHandler - the handler that is called when the application is asked to quit
Throws:
SecurityException - if a security manager exists and it will not allow the caller to invoke System.exit or it denies the RuntimePermission("canProcessApplicationEvents") permission
UnsupportedOperationException - if the current platform does not support the Desktop.Action.APP_QUIT_HANDLER action
Since:
9

setQuitStrategy

public void setQuitStrategy​(QuitStrategy strategy)

Sets the default strategy used to quit this application. The default is calling SYSTEM_EXIT_0.

Parameters:
strategy - the way this application should be shutdown
Throws:
SecurityException - if a security manager exists and it will not allow the caller to invoke System.exit or it denies the RuntimePermission("canProcessApplicationEvents") permission
UnsupportedOperationException - if the current platform does not support the Desktop.Action.APP_QUIT_STRATEGY action
Since:
9
See Also:
QuitStrategy

enableSuddenTermination

public void enableSuddenTermination()

Enables this application to be suddenly terminated. Call this method to indicate your application's state is saved, and requires no notification to be terminated. Letting your application remain terminatable improves the user experience by avoiding re-paging in your application when it's asked to quit. Note: enabling sudden termination will allow your application to be quit without notifying your QuitHandler, or running any shutdown hooks. E.g. user-initiated Cmd-Q, logout, restart, or shutdown requests will effectively "kill -KILL" your application.

Throws:
SecurityException - if a security manager exists and it will not allow the caller to invoke System.exit or it denies the RuntimePermission("canProcessApplicationEvents") permission
UnsupportedOperationException - if the current platform does not support the Desktop.Action.APP_SUDDEN_TERMINATION action
Since:
9
See Also:
disableSuddenTermination()

disableSuddenTermination

public void disableSuddenTermination()

Prevents this application from being suddenly terminated. Call this method to indicate that your application has unsaved state, and may not be terminated without notification.

Throws:
SecurityException - if a security manager exists and it will not allow the caller to invoke System.exit or it denies the RuntimePermission("canProcessApplicationEvents") permission
UnsupportedOperationException - if the current platform does not support the Desktop.Action.APP_SUDDEN_TERMINATION action
Since:
9
See Also:
enableSuddenTermination()

requestForeground

public void requestForeground​(boolean allWindows)

Requests this application to move to the foreground.

Parameters:
allWindows - if all windows of this application should be moved to the foreground, or only the foremost one
Throws:
SecurityException - if a security manager exists and it denies the RuntimePermission("canProcessApplicationEvents") permission.
UnsupportedOperationException - if the current platform does not support the Desktop.Action.APP_REQUEST_FOREGROUND action
Since:
9

openHelpViewer

public void openHelpViewer()

Opens the native help viewer application.

Implementation Note:
Please note that for Mac OS, it opens the native help viewer application if a Help Book has been added to the application bundler and registered in the Info.plist with CFBundleHelpBookFolder
Throws:
SecurityException - if a security manager exists and it denies the RuntimePermission("canProcessApplicationEvents") permission, or it denies the AWTPermission("showWindowWithoutWarningBanner") permission, or the calling thread is not allowed to create a subprocess
UnsupportedOperationException - if the current platform does not support the Desktop.Action.APP_HELP_VIEWER action
Since:
9

setDefaultMenuBar

public void setDefaultMenuBar​(JMenuBar menuBar)

Sets the default menu bar to use when there are no active frames.

Parameters:
menuBar - to use when no other frames are active
Throws:
SecurityException - if a security manager exists and it denies the RuntimePermission("canProcessApplicationEvents") permission.
UnsupportedOperationException - if the current platform does not support the Desktop.Action.APP_MENU_BAR action
Since:
9

browseFileDirectory

public void browseFileDirectory​(File file)

Opens a folder containing the file and selects it in a default system file manager.

Parameters:
file - the file
Throws:
SecurityException - If a security manager exists and its SecurityManager.checkRead(java.lang.String) method denies read access to the file or to its parent, or it denies the AWTPermission("showWindowWithoutWarningBanner") permission, or the calling thread is not allowed to create a subprocess
UnsupportedOperationException - if the current platform does not support the Desktop.Action.BROWSE_FILE_DIR action
NullPointerException - if file is null
IllegalArgumentException - if the specified file or its parent doesn't exist
Since:
9

moveToTrash

public boolean moveToTrash​(File file)

Moves the specified file to the trash.

Parameters:
file - the file
Returns:
returns true if successfully moved the file to the trash.
Throws:
SecurityException - If a security manager exists and its SecurityManager.checkDelete(java.lang.String) method denies deletion of the file
UnsupportedOperationException - if the current platform does not support the Desktop.Action.MOVE_TO_TRASH action
NullPointerException - if file is null
IllegalArgumentException - if the specified file doesn't exist
Since:
9