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java.awt
Class Desktop

java.lang.Object
  java.awt.Desktop

public class Desktop
extends Object

The Desktop class allows a Java application to launch associated applications registered on the native desktop to handle a URI or a file.

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.

An application is registered to a URI or file type; for example, the "sxi" file extension is typically registered to StarOffice. The mechanism of registereing, 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

Nested Class Summary

static class

Desktop.Action Represents an action type.

Method Summary

void	browse(URI uri) Launches the default browser to display a URI.
void	edit(File file) Launches the associated editor application and opens a file for editing.
static Desktop	getDesktop() Returns the Desktop instance of the current browser 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.
void	open(File file) Launches the associated application to open the file.
void	print(File file) Prints a file with the native desktop printing facility, using the associated application's print command.

Methods inherited from 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 browser 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 of the current browser context

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(java.awt.Desktop.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 dosen'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.

If the calling thread does not have the necessary permissions, and this is invoked from within an applet, AppletContext.showDocument() is used. Similarly, if the calling does not have the necessary permissions, and this is invoked from within a Java Web Started application, BasicService.showDocument() is used.

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; and not invoked from within an applet or Java Web Started application

IllegalArgumentException - if the necessary permissions are not available and the URI can not be converted to a URL

See Also:

URI, AWTPermission, AppletContext

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