1 /*
2 * Copyright (c) 1996, 2015, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package java.beans;
27
28 import com.sun.beans.finder.ClassFinder;
29
30 import java.applet.Applet;
31 import java.applet.AppletContext;
32 import java.applet.AppletStub;
33 import java.applet.AudioClip;
34
35 import java.awt.Image;
36
37 import java.beans.beancontext.BeanContext;
38
39 import java.io.IOException;
40 import java.io.InputStream;
41 import java.io.ObjectInputStream;
42 import java.io.ObjectStreamClass;
43 import java.io.StreamCorruptedException;
44
45 import java.lang.reflect.Modifier;
46
47 import java.net.URL;
48
49 import java.util.Enumeration;
50 import java.util.Hashtable;
51 import java.util.Iterator;
52 import java.util.Vector;
53
54 /**
55 * This class provides some general purpose beans control methods.
56 *
57 * @since 1.1
58 */
59
60 public class Beans {
61
62 /**
63 * <p>
64 * Instantiate a JavaBean.
65 * </p>
66 * @return a JavaBean
67 * @param cls the class-loader from which we should create
68 * the bean. If this is null, then the system
69 * class-loader is used.
70 * @param beanName the name of the bean within the class-loader.
71 * For example "sun.beanbox.foobah"
72 *
73 * @exception ClassNotFoundException if the class of a serialized
74 * object could not be found.
75 * @exception IOException if an I/O error occurs.
76 */
77
78 public static Object instantiate(ClassLoader cls, String beanName) throws IOException, ClassNotFoundException {
79 return Beans.instantiate(cls, beanName, null, null);
80 }
81
82 /**
83 * <p>
84 * Instantiate a JavaBean.
85 * </p>
86 * @return a JavaBean
87 *
88 * @param cls the class-loader from which we should create
89 * the bean. If this is null, then the system
90 * class-loader is used.
91 * @param beanName the name of the bean within the class-loader.
92 * For example "sun.beanbox.foobah"
93 * @param beanContext The BeanContext in which to nest the new bean
94 *
95 * @exception ClassNotFoundException if the class of a serialized
96 * object could not be found.
97 * @exception IOException if an I/O error occurs.
98 * @since 1.2
99 */
100
101 public static Object instantiate(ClassLoader cls, String beanName, BeanContext beanContext) throws IOException, ClassNotFoundException {
102 return Beans.instantiate(cls, beanName, beanContext, null);
103 }
104
105 /**
106 * Instantiate a bean.
107 * <p>
108 * The bean is created based on a name relative to a class-loader.
109 * This name should be a dot-separated name such as "a.b.c".
110 * <p>
111 * In Beans 1.0 the given name can indicate either a serialized object
112 * or a class. Other mechanisms may be added in the future. In
113 * beans 1.0 we first try to treat the beanName as a serialized object
114 * name then as a class name.
115 * <p>
116 * When using the beanName as a serialized object name we convert the
117 * given beanName to a resource pathname and add a trailing ".ser" suffix.
118 * We then try to load a serialized object from that resource.
119 * <p>
120 * For example, given a beanName of "x.y", Beans.instantiate would first
121 * try to read a serialized object from the resource "x/y.ser" and if
122 * that failed it would try to load the class "x.y" and create an
123 * instance of that class.
124 * <p>
125 * If the bean is a subtype of java.applet.Applet, then it is given
126 * some special initialization. First, it is supplied with a default
127 * AppletStub and AppletContext. Second, if it was instantiated from
128 * a classname the applet's "init" method is called. (If the bean was
129 * deserialized this step is skipped.)
130 * <p>
131 * Note that for beans which are applets, it is the caller's responsiblity
132 * to call "start" on the applet. For correct behaviour, this should be done
133 * after the applet has been added into a visible AWT container.
134 * <p>
135 * Note that applets created via beans.instantiate run in a slightly
136 * different environment than applets running inside browsers. In
137 * particular, bean applets have no access to "parameters", so they may
138 * wish to provide property get/set methods to set parameter values. We
139 * advise bean-applet developers to test their bean-applets against both
140 * the JDK appletviewer (for a reference browser environment) and the
141 * BDK BeanBox (for a reference bean container).
142 *
143 * @return a JavaBean
144 * @param cls the class-loader from which we should create
145 * the bean. If this is null, then the system
146 * class-loader is used.
147 * @param beanName the name of the bean within the class-loader.
148 * For example "sun.beanbox.foobah"
149 * @param beanContext The BeanContext in which to nest the new bean
150 * @param initializer The AppletInitializer for the new bean
151 *
152 * @exception ClassNotFoundException if the class of a serialized
153 * object could not be found.
154 * @exception IOException if an I/O error occurs.
155 * @since 1.2
156 */
157
158 public static Object instantiate(ClassLoader cls, String beanName, BeanContext beanContext, AppletInitializer initializer)
159 throws IOException, ClassNotFoundException {
160
161 InputStream ins;
162 ObjectInputStream oins = null;
163 Object result = null;
164 boolean serialized = false;
165 IOException serex = null;
166
167 // If the given classloader is null, we check if an
168 // system classloader is available and (if so)
169 // use that instead.
170 // Note that calls on the system class loader will
171 // look in the bootstrap class loader first.
172 if (cls == null) {
173 try {
174 cls = ClassLoader.getSystemClassLoader();
175 } catch (SecurityException ex) {
176 // We're not allowed to access the system class loader.
177 // Drop through.
178 }
179 }
180
181 // Try to find a serialized object with this name
182 final String serName = beanName.replace('.','/').concat(".ser");
183 if (cls == null)
184 ins = ClassLoader.getSystemResourceAsStream(serName);
185 else
186 ins = cls.getResourceAsStream(serName);
187 if (ins != null) {
188 try {
189 if (cls == null) {
190 oins = new ObjectInputStream(ins);
191 } else {
192 oins = new ObjectInputStreamWithLoader(ins, cls);
193 }
194 result = oins.readObject();
195 serialized = true;
196 oins.close();
197 } catch (IOException ex) {
198 ins.close();
199 // Drop through and try opening the class. But remember
200 // the exception in case we can't find the class either.
201 serex = ex;
202 } catch (ClassNotFoundException ex) {
203 ins.close();
204 throw ex;
205 }
206 }
207
208 if (result == null) {
209 // No serialized object, try just instantiating the class
210 Class<?> cl;
211
212 try {
213 cl = ClassFinder.findClass(beanName, cls);
214 } catch (ClassNotFoundException ex) {
215 // There is no appropriate class. If we earlier tried to
216 // deserialize an object and got an IO exception, throw that,
217 // otherwise rethrow the ClassNotFoundException.
218 if (serex != null) {
219 throw serex;
220 }
221 throw ex;
222 }
223
224 if (!Modifier.isPublic(cl.getModifiers())) {
225 throw new ClassNotFoundException("" + cl + " : no public access");
226 }
227
228 /*
229 * Try to instantiate the class.
230 */
231
232 try {
233 @SuppressWarnings("deprecation")
234 Object tmp = cl.newInstance();
235 result = tmp;
236 } catch (Exception ex) {
237 // We have to remap the exception to one in our signature.
238 // But we pass extra information in the detail message.
239 throw new ClassNotFoundException("" + cl + " : " + ex, ex);
240 }
241 }
242
243 if (result != null) {
244
245 // Ok, if the result is an applet initialize it.
246
247 AppletStub stub = null;
248
249 if (result instanceof Applet) {
250 Applet applet = (Applet) result;
251 boolean needDummies = initializer == null;
252
253 if (needDummies) {
254
255 // Figure our the codebase and docbase URLs. We do this
256 // by locating the URL for a known resource, and then
257 // massaging the URL.
258
259 // First find the "resource name" corresponding to the bean
260 // itself. So a serialzied bean "a.b.c" would imply a
261 // resource name of "a/b/c.ser" and a classname of "x.y"
262 // would imply a resource name of "x/y.class".
263
264 final String resourceName;
265
266 if (serialized) {
267 // Serialized bean
268 resourceName = beanName.replace('.','/').concat(".ser");
269 } else {
270 // Regular class
271 resourceName = beanName.replace('.','/').concat(".class");
272 }
273
274 URL objectUrl = null;
275 URL codeBase = null;
276 URL docBase = null;
277
278 // Now get the URL correponding to the resource name.
279 if (cls == null) {
280 objectUrl = ClassLoader.getSystemResource(resourceName);
281 } else
282 objectUrl = cls.getResource(resourceName);
283
284 // If we found a URL, we try to locate the docbase by taking
285 // of the final path name component, and the code base by taking
286 // of the complete resourceName.
287 // So if we had a resourceName of "a/b/c.class" and we got an
288 // objectURL of "file://bert/classes/a/b/c.class" then we would
289 // want to set the codebase to "file://bert/classes/" and the
290 // docbase to "file://bert/classes/a/b/"
291
292 if (objectUrl != null) {
293 String s = objectUrl.toExternalForm();
294
295 if (s.endsWith(resourceName)) {
296 int ix = s.length() - resourceName.length();
297 codeBase = new URL(s.substring(0,ix));
298 docBase = codeBase;
299
300 ix = s.lastIndexOf('/');
301
302 if (ix >= 0) {
303 docBase = new URL(s.substring(0,ix+1));
304 }
305 }
306 }
307
308 // Setup a default context and stub.
309 BeansAppletContext context = new BeansAppletContext(applet);
310
311 stub = (AppletStub)new BeansAppletStub(applet, context, codeBase, docBase);
312 applet.setStub(stub);
313 } else {
314 initializer.initialize(applet, beanContext);
315 }
316
317 // now, if there is a BeanContext, add the bean, if applicable.
318
319 if (beanContext != null) {
320 unsafeBeanContextAdd(beanContext, result);
321 }
322
323 // If it was deserialized then it was already init-ed.
324 // Otherwise we need to initialize it.
325
326 if (!serialized) {
327 // We need to set a reasonable initial size, as many
328 // applets are unhappy if they are started without
329 // having been explicitly sized.
330 applet.setSize(100,100);
331 applet.init();
332 }
333
334 if (needDummies) {
335 ((BeansAppletStub)stub).active = true;
336 } else initializer.activate(applet);
337
338 } else if (beanContext != null) unsafeBeanContextAdd(beanContext, result);
339 }
340
341 return result;
342 }
343
344 @SuppressWarnings("unchecked")
345 private static void unsafeBeanContextAdd(BeanContext beanContext, Object res) {
346 beanContext.add(res);
347 }
348
349 /**
350 * From a given bean, obtain an object representing a specified
351 * type view of that source object.
352 * <p>
353 * The result may be the same object or a different object. If
354 * the requested target view isn't available then the given
355 * bean is returned.
356 * <p>
357 * This method is provided in Beans 1.0 as a hook to allow the
358 * addition of more flexible bean behaviour in the future.
359 *
360 * @return an object representing a specified type view of the
361 * source object
362 * @param bean Object from which we want to obtain a view.
363 * @param targetType The type of view we'd like to get.
364 *
365 */
366 public static Object getInstanceOf(Object bean, Class<?> targetType) {
367 return bean;
368 }
369
370 /**
371 * Check if a bean can be viewed as a given target type.
372 * The result will be true if the Beans.getInstanceof method
373 * can be used on the given bean to obtain an object that
374 * represents the specified targetType type view.
375 *
376 * @param bean Bean from which we want to obtain a view.
377 * @param targetType The type of view we'd like to get.
378 * @return "true" if the given bean supports the given targetType.
379 *
380 */
381 public static boolean isInstanceOf(Object bean, Class<?> targetType) {
382 return Introspector.isSubclass(bean.getClass(), targetType);
383 }
384
385 /**
386 * Test if we are in design-mode.
387 *
388 * @return True if we are running in an application construction
389 * environment.
390 *
391 * @see DesignMode
392 */
393 public static boolean isDesignTime() {
394 return ThreadGroupContext.getContext().isDesignTime();
395 }
396
397 /**
398 * Determines whether beans can assume a GUI is available.
399 *
400 * @return True if we are running in an environment where beans
401 * can assume that an interactive GUI is available, so they
402 * can pop up dialog boxes, etc. This will normally return
403 * true in a windowing environment, and will normally return
404 * false in a server environment or if an application is
405 * running as part of a batch job.
406 *
407 * @see Visibility
408 *
409 */
410 public static boolean isGuiAvailable() {
411 return ThreadGroupContext.getContext().isGuiAvailable();
412 }
413
414 /**
415 * Used to indicate whether of not we are running in an application
416 * builder environment.
417 *
418 * <p>Note that this method is security checked
419 * and is not available to (for example) untrusted applets.
420 * More specifically, if there is a security manager,
421 * its {@code checkPropertiesAccess}
422 * method is called. This could result in a SecurityException.
423 *
424 * @param isDesignTime True if we're in an application builder tool.
425 * @exception SecurityException if a security manager exists and its
426 * {@code checkPropertiesAccess} method doesn't allow setting
427 * of system properties.
428 * @see SecurityManager#checkPropertiesAccess
429 */
430
431 public static void setDesignTime(boolean isDesignTime)
432 throws SecurityException {
433 SecurityManager sm = System.getSecurityManager();
434 if (sm != null) {
435 sm.checkPropertiesAccess();
436 }
437 ThreadGroupContext.getContext().setDesignTime(isDesignTime);
438 }
439
440 /**
441 * Used to indicate whether of not we are running in an environment
442 * where GUI interaction is available.
443 *
444 * <p>Note that this method is security checked
445 * and is not available to (for example) untrusted applets.
446 * More specifically, if there is a security manager,
447 * its {@code checkPropertiesAccess}
448 * method is called. This could result in a SecurityException.
449 *
450 * @param isGuiAvailable True if GUI interaction is available.
451 * @exception SecurityException if a security manager exists and its
452 * {@code checkPropertiesAccess} method doesn't allow setting
453 * of system properties.
454 * @see SecurityManager#checkPropertiesAccess
455 */
456
457 public static void setGuiAvailable(boolean isGuiAvailable)
458 throws SecurityException {
459 SecurityManager sm = System.getSecurityManager();
460 if (sm != null) {
461 sm.checkPropertiesAccess();
462 }
463 ThreadGroupContext.getContext().setGuiAvailable(isGuiAvailable);
464 }
465 }
466
467 /**
468 * This subclass of ObjectInputStream delegates loading of classes to
469 * an existing ClassLoader.
470 */
471
472 class ObjectInputStreamWithLoader extends ObjectInputStream
473 {
474 private ClassLoader loader;
475
476 /**
477 * Loader must be non-null;
478 */
479
480 public ObjectInputStreamWithLoader(InputStream in, ClassLoader loader)
481 throws IOException, StreamCorruptedException {
482
483 super(in);
484 if (loader == null) {
485 throw new IllegalArgumentException("Illegal null argument to ObjectInputStreamWithLoader");
486 }
487 this.loader = loader;
488 }
489
490 /**
491 * Use the given ClassLoader rather than using the system class
492 */
493 @SuppressWarnings("rawtypes")
494 protected Class resolveClass(ObjectStreamClass classDesc)
495 throws IOException, ClassNotFoundException {
496
497 String cname = classDesc.getName();
498 return ClassFinder.resolveClass(cname, this.loader);
499 }
500 }
501
502 /**
503 * Package private support class. This provides a default AppletContext
504 * for beans which are applets.
505 */
506
507 class BeansAppletContext implements AppletContext {
508 Applet target;
509 Hashtable<URL,Object> imageCache = new Hashtable<>();
510
511 BeansAppletContext(Applet target) {
512 this.target = target;
513 }
514
515 public AudioClip getAudioClip(URL url) {
516 // We don't currently support audio clips in the Beans.instantiate
517 // applet context, unless by some luck there exists a URL content
518 // class that can generate an AudioClip from the audio URL.
519 try {
520 return (AudioClip) url.getContent();
521 } catch (Exception ex) {
522 return null;
523 }
524 }
525
526 public synchronized Image getImage(URL url) {
527 Object o = imageCache.get(url);
528 if (o != null) {
529 return (Image)o;
530 }
531 try {
532 o = url.getContent();
533 if (o == null) {
534 return null;
535 }
536 if (o instanceof Image) {
537 imageCache.put(url, o);
538 return (Image) o;
539 }
540 // Otherwise it must be an ImageProducer.
541 Image img = target.createImage((java.awt.image.ImageProducer)o);
542 imageCache.put(url, img);
543 return img;
544
545 } catch (Exception ex) {
546 return null;
547 }
548 }
549
550 public Applet getApplet(String name) {
551 return null;
552 }
553
554 public Enumeration<Applet> getApplets() {
555 Vector<Applet> applets = new Vector<>();
556 applets.addElement(target);
557 return applets.elements();
558 }
559
560 public void showDocument(URL url) {
561 // We do nothing.
562 }
563
564 public void showDocument(URL url, String target) {
565 // We do nothing.
566 }
567
568 public void showStatus(String status) {
569 // We do nothing.
570 }
571
572 public void setStream(String key, InputStream stream)throws IOException{
573 // We do nothing.
574 }
575
576 public InputStream getStream(String key){
577 // We do nothing.
578 return null;
579 }
580
581 public Iterator<String> getStreamKeys(){
582 // We do nothing.
583 return null;
584 }
585 }
586
587 /**
588 * Package private support class. This provides an AppletStub
589 * for beans which are applets.
590 */
591 class BeansAppletStub implements AppletStub {
592 transient boolean active;
593 transient Applet target;
594 transient AppletContext context;
595 transient URL codeBase;
596 transient URL docBase;
597
598 BeansAppletStub(Applet target,
599 AppletContext context, URL codeBase,
600 URL docBase) {
601 this.target = target;
602 this.context = context;
603 this.codeBase = codeBase;
604 this.docBase = docBase;
605 }
606
607 public boolean isActive() {
608 return active;
609 }
610
611 public URL getDocumentBase() {
612 // use the root directory of the applet's class-loader
613 return docBase;
614 }
615
616 public URL getCodeBase() {
617 // use the directory where we found the class or serialized object.
618 return codeBase;
619 }
620
621 public String getParameter(String name) {
622 return null;
623 }
624
625 public AppletContext getAppletContext() {
626 return context;
627 }
628
629 public void appletResize(int width, int height) {
630 // we do nothing.
631 }
632 }