001 /*
002 * Copyright 2005-2006 Sun Microsystems, Inc. All Rights Reserved.
003 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
004 *
005 * This code is free software; you can redistribute it and/or modify it
006 * under the terms of the GNU General Public License version 2 only, as
007 * published by the Free Software Foundation. Sun designates this
008 * particular file as subject to the "Classpath" exception as provided
009 * by Sun in the LICENSE file that accompanied this code.
010 *
011 * This code is distributed in the hope that it will be useful, but WITHOUT
012 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
013 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
014 * version 2 for more details (a copy is included in the LICENSE file that
015 * accompanied this code).
016 *
017 * You should have received a copy of the GNU General Public License version
018 * 2 along with this work; if not, write to the Free Software Foundation,
019 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
020 *
021 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
022 * CA 95054 USA or visit www.sun.com if you need additional information or
023 * have any questions.
024 */
025
026 package java.awt;
027
028 import java.io.File;
029 import java.io.IOException;
030 import java.net.URISyntaxException;
031 import java.net.URI;
032 import java.net.URL;
033 import java.net.MalformedURLException;
034 import java.awt.AWTPermission;
035 import java.awt.GraphicsEnvironment;
036 import java.awt.HeadlessException;
037 import java.awt.peer.DesktopPeer;
038 import sun.awt.SunToolkit;
039 import sun.awt.HeadlessToolkit;
040 import java.io.FilePermission;
041 import sun.security.util.SecurityConstants;
042
043 /**
044 * The {@code Desktop} class allows a Java application to launch
045 * associated applications registered on the native desktop to handle
046 * a {@link java.net.URI} or a file.
047 *
048 * <p> Supported operations include:
049 * <ul>
050 * <li>launching the user-default browser to show a specified
051 * URI;</li>
052 * <li>launching the user-default mail client with an optional
053 * {@code mailto} URI;</li>
054 * <li>launching a registered application to open, edit or print a
055 * specified file.</li>
056 * </ul>
057 *
058 * <p> This class provides methods corresponding to these
059 * operations. The methods look for the associated application
060 * registered on the current platform, and launch it to handle a URI
061 * or file. If there is no associated application or the associated
062 * application fails to be launched, an exception is thrown.
063 *
064 * <p> An application is registered to a URI or file type; for
065 * example, the {@code "sxi"} file extension is typically registered
066 * to StarOffice. The mechanism of registering, accessing, and
067 * launching the associated application is platform-dependent.
068 *
069 * <p> Each operation is an action type represented by the {@link
070 * Desktop.Action} class.
071 *
072 * <p> Note: when some action is invoked and the associated
073 * application is executed, it will be executed on the same system as
074 * the one on which the Java application was launched.
075 *
076 * @since 1.6
077 * @author Armin Chen
078 * @author George Zhang
079 */
080 public class Desktop {
081
082 /**
083 * Represents an action type. Each platform supports a different
084 * set of actions. You may use the {@link Desktop#isSupported}
085 * method to determine if the given action is supported by the
086 * current platform.
087 * @see java.awt.Desktop#isSupported(java.awt.Desktop.Action)
088 * @since 1.6
089 */
090 public static enum Action {
091 /**
092 * Represents an "open" action.
093 * @see Desktop#open(java.io.File)
094 */
095 OPEN,
096 /**
097 * Represents an "edit" action.
098 * @see Desktop#edit(java.io.File)
099 */
100 EDIT,
101 /**
102 * Represents a "print" action.
103 * @see Desktop#print(java.io.File)
104 */
105 PRINT,
106 /**
107 * Represents a "mail" action.
108 * @see Desktop#mail()
109 * @see Desktop#mail(java.net.URI)
110 */
111 MAIL,
112 /**
113 * Represents a "browse" action.
114 * @see Desktop#browse(java.net.URI)
115 */
116 BROWSE
117 };
118
119 private DesktopPeer peer;
120
121 /**
122 * Suppresses default constructor for noninstantiability.
123 */
124 private Desktop() {
125 peer = Toolkit.getDefaultToolkit().createDesktopPeer(this );
126 }
127
128 /**
129 * Returns the <code>Desktop</code> instance of the current
130 * browser context. On some platforms the Desktop API may not be
131 * supported; use the {@link #isDesktopSupported} method to
132 * determine if the current desktop is supported.
133 * @return the Desktop instance of the current browser context
134 * @throws HeadlessException if {@link
135 * GraphicsEnvironment#isHeadless()} returns {@code true}
136 * @throws UnsupportedOperationException if this class is not
137 * supported on the current platform
138 * @see #isDesktopSupported()
139 * @see java.awt.GraphicsEnvironment#isHeadless
140 */
141 public static synchronized Desktop getDesktop() {
142 if (GraphicsEnvironment.isHeadless())
143 throw new HeadlessException();
144 if (!Desktop.isDesktopSupported()) {
145 throw new UnsupportedOperationException(
146 "Desktop API is not "
147 + "supported on the current platform");
148 }
149
150 sun.awt.AppContext context = sun.awt.AppContext.getAppContext();
151 Desktop desktop = (Desktop) context.get(Desktop.class);
152
153 if (desktop == null) {
154 desktop = new Desktop();
155 context.put(Desktop.class, desktop);
156 }
157
158 return desktop;
159 }
160
161 /**
162 * Tests whether this class is supported on the current platform.
163 * If it's supported, use {@link #getDesktop()} to retrieve an
164 * instance.
165 *
166 * @return <code>true</code> if this class is supported on the
167 * current platform; <code>false</code> otherwise
168 * @see #getDesktop()
169 */
170 public static boolean isDesktopSupported() {
171 Toolkit defaultToolkit = Toolkit.getDefaultToolkit();
172 if (defaultToolkit instanceof SunToolkit) {
173 return ((SunToolkit) defaultToolkit).isDesktopSupported();
174 }
175 return false;
176 }
177
178 /**
179 * Tests whether an action is supported on the current platform.
180 *
181 * <p>Even when the platform supports an action, a file or URI may
182 * not have a registered application for the action. For example,
183 * most of the platforms support the {@link Desktop.Action#OPEN}
184 * action. But for a specific file, there may not be an
185 * application registered to open it. In this case, {@link
186 * #isSupported} may return {@code true}, but the corresponding
187 * action method will throw an {@link IOException}.
188 *
189 * @param action the specified {@link Action}
190 * @return <code>true</code> if the specified action is supported on
191 * the current platform; <code>false</code> otherwise
192 * @see Desktop.Action
193 */
194 public boolean isSupported(Action action) {
195 return peer.isSupported(action);
196 }
197
198 /**
199 * Checks if the file is a valid file and readable.
200 *
201 * @throws SecurityException If a security manager exists and its
202 * {@link SecurityManager#checkRead(java.lang.String)} method
203 * denies read access to the file
204 * @throws NullPointerException if file is null
205 * @throws IllegalArgumentException if file doesn't exist
206 */
207 private static void checkFileValidation(File file) {
208 if (file == null)
209 throw new NullPointerException("File must not be null");
210
211 if (!file.exists()) {
212 throw new IllegalArgumentException("The file: "
213 + file.getPath() + " doesn't exist.");
214 }
215
216 file.canRead();
217 }
218
219 /**
220 * Checks if the action type is supported.
221 *
222 * @param actionType the action type in question
223 * @throws UnsupportedOperationException if the specified action type is not
224 * supported on the current platform
225 */
226 private void checkActionSupport(Action actionType) {
227 if (!isSupported(actionType)) {
228 throw new UnsupportedOperationException(
229 "The "
230 + actionType.name()
231 + " action is not supported on the current platform!");
232 }
233 }
234
235 /**
236 * Calls to the security manager's <code>checkPermission</code> method with
237 * an <code>AWTPermission("showWindowWithoutWarningBanner")</code>
238 * permission.
239 */
240 private void checkAWTPermission() {
241 SecurityManager sm = System.getSecurityManager();
242 if (sm != null) {
243 sm.checkPermission(new AWTPermission(
244 "showWindowWithoutWarningBanner"));
245 }
246 }
247
248 /**
249 * Launches the associated application to open the file.
250 *
251 * <p> If the specified file is a directory, the file manager of
252 * the current platform is launched to open it.
253 *
254 * @param file the file to be opened with the associated application
255 * @throws NullPointerException if {@code file} is {@code null}
256 * @throws IllegalArgumentException if the specified file doesn't
257 * exist
258 * @throws UnsupportedOperationException if the current platform
259 * does not support the {@link Desktop.Action#OPEN} action
260 * @throws IOException if the specified file has no associated
261 * application or the associated application fails to be launched
262 * @throws SecurityException if a security manager exists and its
263 * {@link java.lang.SecurityManager#checkRead(java.lang.String)}
264 * method denies read access to the file, or it denies the
265 * <code>AWTPermission("showWindowWithoutWarningBanner")</code>
266 * permission, or the calling thread is not allowed to create a
267 * subprocess
268 * @see java.awt.AWTPermission
269 */
270 public void open(File file) throws IOException {
271 checkAWTPermission();
272 checkExec();
273 checkActionSupport(Action.OPEN);
274 checkFileValidation(file);
275
276 peer.open(file);
277 }
278
279 /**
280 * Launches the associated editor application and opens a file for
281 * editing.
282 *
283 * @param file the file to be opened for editing
284 * @throws NullPointerException if the specified file is {@code null}
285 * @throws IllegalArgumentException if the specified file doesn't
286 * exist
287 * @throws UnsupportedOperationException if the current platform
288 * does not support the {@link Desktop.Action#EDIT} action
289 * @throws IOException if the specified file has no associated
290 * editor, or the associated application fails to be launched
291 * @throws SecurityException if a security manager exists and its
292 * {@link java.lang.SecurityManager#checkRead(java.lang.String)}
293 * method denies read access to the file, or {@link
294 * java.lang.SecurityManager#checkWrite(java.lang.String)} method
295 * denies write access to the file, or it denies the
296 * <code>AWTPermission("showWindowWithoutWarningBanner")</code>
297 * permission, or the calling thread is not allowed to create a
298 * subprocess
299 * @see java.awt.AWTPermission
300 */
301 public void edit(File file) throws IOException {
302 checkAWTPermission();
303 checkExec();
304 checkActionSupport(Action.EDIT);
305 file.canWrite();
306 checkFileValidation(file);
307
308 peer.edit(file);
309 }
310
311 /**
312 * Prints a file with the native desktop printing facility, using
313 * the associated application's print command.
314 *
315 * @param file the file to be printed
316 * @throws NullPointerException if the specified file is {@code
317 * null}
318 * @throws IllegalArgumentException if the specified file doesn't
319 * exist
320 * @throws UnsupportedOperationException if the current platform
321 * does not support the {@link Desktop.Action#PRINT} action
322 * @throws IOException if the specified file has no associated
323 * application that can be used to print it
324 * @throws SecurityException if a security manager exists and its
325 * {@link java.lang.SecurityManager#checkRead(java.lang.String)}
326 * method denies read access to the file, or its {@link
327 * java.lang.SecurityManager#checkPrintJobAccess()} method denies
328 * the permission to print the file, or the calling thread is not
329 * allowed to create a subprocess
330 */
331 public void print(File file) throws IOException {
332 checkExec();
333 SecurityManager sm = System.getSecurityManager();
334 if (sm != null) {
335 sm.checkPrintJobAccess();
336 }
337 checkActionSupport(Action.PRINT);
338 checkFileValidation(file);
339
340 peer.print(file);
341 }
342
343 /**
344 * Launches the default browser to display a {@code URI}.
345 * If the default browser is not able to handle the specified
346 * {@code URI}, the application registered for handling
347 * {@code URIs} of the specified type is invoked. The application
348 * is determined from the protocol and path of the {@code URI}, as
349 * defined by the {@code URI} class.
350 * <p>
351 * If the calling thread does not have the necessary permissions,
352 * and this is invoked from within an applet,
353 * {@code AppletContext.showDocument()} is used. Similarly, if the calling
354 * does not have the necessary permissions, and this is invoked from within
355 * a Java Web Started application, {@code BasicService.showDocument()}
356 * is used.
357 *
358 * @param uri the URI to be displayed in the user default browser
359 * @throws NullPointerException if {@code uri} is {@code null}
360 * @throws UnsupportedOperationException if the current platform
361 * does not support the {@link Desktop.Action#BROWSE} action
362 * @throws IOException if the user default browser is not found,
363 * or it fails to be launched, or the default handler application
364 * failed to be launched
365 * @throws SecurityException if a security manager exists and it
366 * denies the
367 * <code>AWTPermission("showWindowWithoutWarningBanner")</code>
368 * permission, or the calling thread is not allowed to create a
369 * subprocess; and not invoked from within an applet or Java Web Started
370 * application
371 * @throws IllegalArgumentException if the necessary permissions
372 * are not available and the URI can not be converted to a {@code URL}
373 * @see java.net.URI
374 * @see java.awt.AWTPermission
375 * @see java.applet.AppletContext
376 */
377 public void browse(URI uri) throws IOException {
378 SecurityException securityException = null;
379 try {
380 checkAWTPermission();
381 checkExec();
382 } catch (SecurityException e) {
383 securityException = e;
384 }
385 checkActionSupport(Action.BROWSE);
386 if (uri == null) {
387 throw new NullPointerException();
388 }
389 if (securityException == null) {
390 peer.browse(uri);
391 return;
392 }
393
394 // Calling thread doesn't have necessary priviledges.
395 // Delegate to DesktopBrowse so that it can work in
396 // applet/webstart.
397 URL url = null;
398 try {
399 url = uri.toURL();
400 } catch (MalformedURLException e) {
401 throw new IllegalArgumentException(
402 "Unable to convert URI to URL", e);
403 }
404 sun.awt.DesktopBrowse db = sun.awt.DesktopBrowse.getInstance();
405 if (db == null) {
406 // Not in webstart/applet, throw the exception.
407 throw securityException;
408 }
409 db.browse(url);
410 }
411
412 /**
413 * Launches the mail composing window of the user default mail
414 * client.
415 *
416 * @throws UnsupportedOperationException if the current platform
417 * does not support the {@link Desktop.Action#MAIL} action
418 * @throws IOException if the user default mail client is not
419 * found, or it fails to be launched
420 * @throws SecurityException if a security manager exists and it
421 * denies the
422 * <code>AWTPermission("showWindowWithoutWarningBanner")</code>
423 * permission, or the calling thread is not allowed to create a
424 * subprocess
425 * @see java.awt.AWTPermission
426 */
427 public void mail() throws IOException {
428 checkAWTPermission();
429 checkExec();
430 checkActionSupport(Action.MAIL);
431 URI mailtoURI = null;
432 try {
433 mailtoURI = new URI("mailto:?");
434 peer.mail(mailtoURI);
435 } catch (URISyntaxException e) {
436 // won't reach here.
437 }
438 }
439
440 /**
441 * Launches the mail composing window of the user default mail
442 * client, filling the message fields specified by a {@code
443 * mailto:} URI.
444 *
445 * <p> A <code>mailto:</code> URI can specify message fields
446 * including <i>"to"</i>, <i>"cc"</i>, <i>"subject"</i>,
447 * <i>"body"</i>, etc. See <a
448 * href="http://www.ietf.org/rfc/rfc2368.txt">The mailto URL
449 * scheme (RFC 2368)</a> for the {@code mailto:} URI specification
450 * details.
451 *
452 * @param mailtoURI the specified {@code mailto:} URI
453 * @throws NullPointerException if the specified URI is {@code
454 * null}
455 * @throws IllegalArgumentException if the URI scheme is not
456 * <code>"mailto"</code>
457 * @throws UnsupportedOperationException if the current platform
458 * does not support the {@link Desktop.Action#MAIL} action
459 * @throws IOException if the user default mail client is not
460 * found or fails to be launched
461 * @throws SecurityException if a security manager exists and it
462 * denies the
463 * <code>AWTPermission("showWindowWithoutWarningBanner")</code>
464 * permission, or the calling thread is not allowed to create a
465 * subprocess
466 * @see java.net.URI
467 * @see java.awt.AWTPermission
468 */
469 public void mail(URI mailtoURI) throws IOException {
470 checkAWTPermission();
471 checkExec();
472 checkActionSupport(Action.MAIL);
473 if (mailtoURI == null)
474 throw new NullPointerException();
475
476 if (!"mailto".equalsIgnoreCase(mailtoURI.getScheme())) {
477 throw new IllegalArgumentException(
478 "URI scheme is not \"mailto\"");
479 }
480
481 peer.mail(mailtoURI);
482 }
483
484 private void checkExec() throws SecurityException {
485 SecurityManager sm = System.getSecurityManager();
486 if (sm != null) {
487 sm.checkPermission(new FilePermission("<<ALL FILES>>",
488 SecurityConstants.FILE_EXECUTE_ACTION));
489 }
490 }
491 }
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