1 |
/* java.beans.Beans |
/* java.beans.Beans |
2 |
Copyright (C) 1998, 1999 Free Software Foundation, Inc. |
Copyright (C) 1998, 1999, 2004, 2005 Free Software Foundation, Inc. |
3 |
|
|
4 |
This file is part of GNU Classpath. |
This file is part of GNU Classpath. |
5 |
|
|
35 |
obligated to do so. If you do not wish to do so, delete this |
obligated to do so. If you do not wish to do so, delete this |
36 |
exception statement from your version. */ |
exception statement from your version. */ |
37 |
|
|
|
|
|
38 |
package java.beans; |
package java.beans; |
39 |
|
|
40 |
|
import gnu.java.beans.DummyAppletStub; |
41 |
import gnu.java.io.ClassLoaderObjectInputStream; |
import gnu.java.io.ClassLoaderObjectInputStream; |
42 |
|
|
43 |
import java.applet.Applet; |
import java.applet.Applet; |
44 |
|
import java.beans.beancontext.BeanContext; |
45 |
import java.io.IOException; |
import java.io.IOException; |
|
import java.io.InputStream; |
|
46 |
import java.io.ObjectInputStream; |
import java.io.ObjectInputStream; |
47 |
|
import java.net.URL; |
48 |
|
|
49 |
/** |
/** |
50 |
* <code>Beans</code> provides some helper methods that allow the basic |
* <code>Beans</code> provides some helper methods that allow the basic |
51 |
* operations of Bean-ness. |
* operations of Bean-ness. |
52 |
* |
* |
53 |
* @author John Keiser |
* @author John Keiser |
54 |
|
* @author Robert Schuster |
55 |
|
* |
56 |
* @since 1.1 |
* @since 1.1 |
57 |
* @version 1.1.0, 29 Jul 1998 |
* @status updated to 1.4 |
58 |
* |
* |
59 |
*/ |
*/ |
60 |
public class Beans |
public class Beans |
69 |
*/ |
*/ |
70 |
public Beans() |
public Beans() |
71 |
{ |
{ |
72 |
// Do nothing here. |
// Does intentionally nothing here. |
|
} |
|
|
|
|
|
/** |
|
|
* Allows you to instantiate a Bean. This method takes |
|
|
* a ClassLoader from which to read the Bean and the |
|
|
* name of the Bean.<P> |
|
|
* |
|
|
* The Bean name should be a dotted name, like a class. |
|
|
* It can represent several things. Beans will search |
|
|
* for the Bean using the name like this:<P> |
|
|
* <OL> |
|
|
* <LI>Searches for a serialized instance of the Bean |
|
|
* using getResource(), mangling the Bean name by |
|
|
* replacing the dots with slashes and appending .ser |
|
|
* (for example, gnu.beans.BlahDeBlah would cause |
|
|
* Beans to search for gnu/beans/BlahDeBlah.ser using |
|
|
* getResource()).</LI> |
|
|
* <LI>Searches for the Bean class using the beanName, |
|
|
* and then instantiates it with the no-arg constructor. |
|
|
* At that point, if it is an Applet, it provides it |
|
|
* with AppletContext and AppletStub, and then calls |
|
|
* init().</LI> |
|
|
* </OL> |
|
|
* |
|
|
* @param cl the ClassLoader to use, or <CODE>null</CODE> |
|
|
* to use the default ClassLoader. |
|
|
* @param beanName the name of the Bean. |
|
|
* |
|
|
* @return the Bean. |
|
|
* |
|
|
* @XXX |
|
|
*/ |
|
|
public static Object instantiate (ClassLoader cl, String beanName) |
|
|
throws IOException, ClassNotFoundException |
|
|
{ |
|
|
Object bean; |
|
|
InputStream serStream; |
|
|
|
|
|
if (cl == null) |
|
|
{ |
|
|
serStream = ClassLoader.getSystemResourceAsStream |
|
|
(beanName.replace ('.','/')+".ser"); |
|
|
} |
|
|
else |
|
|
{ |
|
|
serStream = cl.getResourceAsStream (beanName.replace ('.', '/') |
|
|
+ ".ser"); |
|
|
} |
|
|
|
|
|
if (serStream != null) |
|
|
{ |
|
|
if(cl == null) |
|
|
{ |
|
|
ObjectInputStream ois = new ObjectInputStream(serStream); |
|
|
bean = ois.readObject(); |
|
|
} |
|
|
else |
|
|
{ |
|
|
ClassLoaderObjectInputStream ois = |
|
|
new ClassLoaderObjectInputStream (serStream, cl); |
|
|
bean = ois.readObject(); |
|
|
} |
|
|
} |
|
|
else if(cl == null) |
|
|
{ |
|
|
Class beanClass = Class.forName(beanName); |
|
|
try |
|
|
{ |
|
|
bean = beanClass.newInstance(); |
|
|
} |
|
|
catch(IllegalAccessException E) |
|
|
{ |
|
|
bean = null; |
|
|
} |
|
|
catch(InstantiationException E) |
|
|
{ |
|
|
bean = null; |
|
|
} |
|
|
} |
|
|
else |
|
|
{ |
|
|
Class beanClass = cl.loadClass(beanName); |
|
|
try |
|
|
{ |
|
|
bean = beanClass.newInstance(); |
|
|
} |
|
|
catch(IllegalAccessException E) |
|
|
{ |
|
|
bean = null; |
|
|
} |
|
|
catch(InstantiationException E) |
|
|
{ |
|
|
bean = null; |
|
|
} |
|
|
} |
|
|
|
|
|
if(bean instanceof Applet) |
|
|
{ |
|
|
Applet a = (Applet)bean; |
|
|
//a.setAppletContext(???); |
|
|
//a.setStub(???); |
|
|
if(serStream == null) |
|
|
{ |
|
|
a.init(); |
|
|
} |
|
|
} |
|
|
|
|
|
return bean; |
|
|
} |
|
|
|
|
|
/** |
|
|
* Get the Bean as a different class type. |
|
|
* This should be used instead of casting to get a new |
|
|
* type view of a Bean, because in the future there may |
|
|
* be new types of Bean, even Beans spanning multiple |
|
|
* Objects. |
|
|
* |
|
|
* @param bean the Bean to cast. |
|
|
* @param newClass the Class to cast it to. |
|
|
* |
|
|
* @return the Bean as a new view, or if the operation |
|
|
* could not be performed, the Bean itself. |
|
|
*/ |
|
|
public static Object getInstanceOf(Object bean, Class newClass) |
|
|
{ |
|
|
return bean; |
|
|
} |
|
|
|
|
|
/** |
|
|
* Determine whether the Bean can be cast to a different |
|
|
* class type. |
|
|
* This should be used instead of instanceof to determine |
|
|
* a Bean's castability, because in the future there may |
|
|
* be new types of Bean, even Beans spanning multiple |
|
|
* Objects. |
|
|
* |
|
|
* @param bean the Bean to cast. |
|
|
* @param newBeanClass the Class to cast it to. |
|
|
* |
|
|
* @return whether the Bean can be cast to the class type |
|
|
* in question. |
|
|
*/ |
|
|
public static boolean isInstanceOf(Object bean, Class newBeanClass) |
|
|
{ |
|
|
return newBeanClass.isInstance(bean); |
|
73 |
} |
} |
74 |
|
|
75 |
/** |
/** Creates a bean. |
76 |
* Find out whether the GUI is available to use. |
* <p>This is a convenience method that calls <code>instantiate(cl, beanName, null, null)</code>.</p> |
77 |
* Defaults to true. |
* |
78 |
* |
* @see instantiate(ClassLoader, String, BeanContext, AppletInitializer) |
79 |
* @return whether the GUI is available to use. |
* @param cl ClassLoader to be used or <code>null</code> for the system classloader. |
80 |
*/ |
* @param beanName Name of a serialized bean or class name. |
81 |
public static boolean isGuiAvailable() |
* @return A newly created bean. |
82 |
{ |
* @throws IOException If access of an IO resource failed. |
83 |
return guiAvailable; |
* @throws ClassNotFoundException If the class name is not known or does not lead to a proper bean class. |
84 |
} |
*/ |
85 |
|
public static Object instantiate(ClassLoader cl, String beanName) |
86 |
|
throws IOException, ClassNotFoundException |
87 |
|
{ |
88 |
|
return instantiate(cl, beanName, null, null); |
89 |
|
} |
90 |
|
|
91 |
|
/** Creates a bean. |
92 |
|
* |
93 |
|
* <p>This is a convenience method that calls <code>instantiate(cl, beanName, beanContext, null)</code>.</p> |
94 |
|
* |
95 |
|
* @see instantiate(ClassLoader, String, BeanContext, AppletInitializer) |
96 |
|
* @param cl ClassLoader to be used or <code>null</code> for the system classloader. |
97 |
|
* @param beanName Name of a serialized bean or class name. |
98 |
|
* @param beanContext Context to which the newly created Bean should be added. |
99 |
|
* @return A newly created bean. |
100 |
|
* @throws IOException If access of an IO resource failed. |
101 |
|
* @throws ClassNotFoundException If the class name is not known or does not lead to a proper bean class. |
102 |
|
*/ |
103 |
|
public static Object instantiate( |
104 |
|
ClassLoader cl, |
105 |
|
String beanName, |
106 |
|
BeanContext beanContext) |
107 |
|
throws IOException, ClassNotFoundException |
108 |
|
{ |
109 |
|
return instantiate(cl, beanName, beanContext, null); |
110 |
|
} |
111 |
|
|
112 |
|
/** Instantiates a bean according to Beans 1.0. |
113 |
|
* |
114 |
|
* <p>In Beans 1.0 the instantiation scheme is as follows:</p> |
115 |
|
* <p>The name should be dot-separated (e.g "place.for.beans.myBean") and indicate either a |
116 |
|
* serialized object or a class name. In the first case all dots in the name are replaced with |
117 |
|
* slashes ('/') and ".ser" is appended ("place.for.beans.myBean" becomes "place/for/beans/myBean.ser"). |
118 |
|
* The bean is then loaded as an application or system resource depending on whether a |
119 |
|
* <code>ClassLoader</code> was provided.</p> |
120 |
|
* |
121 |
|
* <p>If no such resource exists or if it contains no bean the name is interpreted as a class name of |
122 |
|
* which an instance is then created.</p> |
123 |
|
* |
124 |
|
* <p>If a <code>BeanContext</code> instance is available the created bean is added to it.</p> |
125 |
|
* |
126 |
|
* <p>If the created Bean is an <code>Applet</code> or subclass and an <code>AppletInitializer</code> |
127 |
|
* instance is available the applet is initialized and afterwards activated using the initializer. Additionally |
128 |
|
* every instantiated <code>Applet</code> bean is initialized using the {@link Applet.init} method. |
129 |
|
* Furthermore every applet gets a default <code>AppletStub</code>. The <code>Applet</code>'s |
130 |
|
* document base is the location of the ".ser" file if it was deserialized or the location of its class |
131 |
|
* file if it was instantiated.</p> |
132 |
|
* |
133 |
|
* <p>A <code>ClassNotFoundException</code> is not only thrown when a class name was unknown |
134 |
|
* but even when the class has public no-argument constructor |
135 |
|
* (<code>IllegalAccessException</code> is wrapped) or an exception is thrown while |
136 |
|
* invoking such a constructor (causing exception is wrapped).</p> |
137 |
|
* |
138 |
|
* @param cl ClassLoader to be used or <code>null</code> for the system classloader. |
139 |
|
* @param beanName Name of a serialized bean or class name. |
140 |
|
* @param beanContext Context to which the newly created Bean should be added. |
141 |
|
* @param initializer The AppletInitializer which is used for initializing <code>Applet</code> beans. |
142 |
|
* @return A newly created bean. |
143 |
|
* @throws IOException If access of an IO resource failed. |
144 |
|
* @throws ClassNotFoundException If the class name is not known or does not lead to a proper bean class. |
145 |
|
*/ |
146 |
|
public static Object instantiate( |
147 |
|
ClassLoader cl, |
148 |
|
String beanName, |
149 |
|
BeanContext beanContext, |
150 |
|
AppletInitializer initializer) |
151 |
|
throws IOException, ClassNotFoundException |
152 |
|
{ |
153 |
|
Object bean = null; |
154 |
|
URL beanLocation = null; |
155 |
|
URL classLocation = null; |
156 |
|
|
157 |
|
// Converts bean name into a resource name (eg. "a.b.c" -> "a/b/c"). |
158 |
|
String resourceName = beanName.replace('.', '/'); |
159 |
|
|
160 |
|
/* Tries to get an input stream of the Bean, reading it as a system resource |
161 |
|
* if no ClassLoader is present or as an application resource if a classloader |
162 |
|
* is given. |
163 |
|
*/ |
164 |
|
beanLocation = |
165 |
|
(cl == null) |
166 |
|
? ClassLoader.getSystemResource(resourceName + ".ser") |
167 |
|
: cl.getResource(resourceName + ".ser"); |
168 |
|
|
169 |
|
// Reads the serialized Bean from the returned URL. |
170 |
|
if (beanLocation != null) |
171 |
|
{ |
172 |
|
// Deserializes the bean instance. |
173 |
|
ObjectInputStream ois = |
174 |
|
(cl == null) |
175 |
|
? new ObjectInputStream(beanLocation.openStream()) |
176 |
|
: new ClassLoaderObjectInputStream( |
177 |
|
beanLocation.openStream(), |
178 |
|
cl); |
179 |
|
|
180 |
/** |
bean = ois.readObject(); |
|
* Find out whether it is design time. Design time means |
|
|
* we are in a RAD tool. |
|
|
* Defaults to false. |
|
|
* |
|
|
* @return whether it is design time. |
|
|
*/ |
|
|
public static boolean isDesignTime() |
|
|
{ |
|
|
return designTime; |
|
|
} |
|
181 |
|
|
182 |
/** |
/* Implementation note: The result of ObjectInputStream.readObject() |
183 |
* Set whether the GUI is available to use. |
* may have been null at this point (its a valid value to deserialize) |
184 |
* @param guiAvailable whether the GUI is available to use. |
* and we explicitly want to try instantiation in such a case |
185 |
*/ |
* (this is important for compatibility). |
186 |
public static void setGuiAvailable(boolean guiAvailable) |
*/ |
187 |
throws SecurityException |
} |
188 |
{ |
|
189 |
Beans.guiAvailable = guiAvailable; |
// Instantiates the Bean using reflective instantiation if it has not been created yet. |
190 |
} |
if (bean == null) |
191 |
|
{ |
192 |
|
// Makes sure that the deserialization was NOT done. |
193 |
|
beanLocation = null; |
194 |
|
|
195 |
|
Class beanClass; |
196 |
|
if (cl == null) |
197 |
|
{ |
198 |
|
beanClass = Class.forName(beanName); |
199 |
|
classLocation = |
200 |
|
ClassLoader.getSystemResource(resourceName + ".class"); |
201 |
|
} |
202 |
|
else |
203 |
|
{ |
204 |
|
beanClass = cl.loadClass(beanName); |
205 |
|
classLocation = cl.getResource(resourceName + ".class"); |
206 |
|
} |
207 |
|
|
208 |
|
// Instantiates and optionally registers the new bean. |
209 |
|
try |
210 |
|
{ |
211 |
|
bean = beanClass.newInstance(); |
212 |
|
} |
213 |
|
catch(Exception e) { |
214 |
|
/* Wraps all kinds of Exceptions in a ClassNotFoundException (this behavior |
215 |
|
* matches with official >= 1.5, this was different for <=1.4) |
216 |
|
*/ |
217 |
|
throw new ClassNotFoundException(null, e); |
218 |
|
} |
219 |
|
} |
220 |
|
|
221 |
|
/* Applet beans are treated in the following way: |
222 |
|
* - all AppletS get a default AppletStub |
223 |
|
* - all AppletS are initialized using the AppletInitializer instance (if it is available) |
224 |
|
* - as every other Bean Applets are added to a BeanContext if one is available |
225 |
|
* - each instantiated Applet is initialized using Applet.init() (this is not done for deserialized ones) |
226 |
|
* - finally AppletS get activated using the AppletInitializerS activate-Method |
227 |
|
* |
228 |
|
* The order of operations is important for compatibility. |
229 |
|
*/ |
230 |
|
Applet applet = null; |
231 |
|
if (bean instanceof Applet) |
232 |
|
{ |
233 |
|
// Makes a second instanceof call unneccessary (instanceof is expensive). |
234 |
|
applet = (Applet) bean; |
235 |
|
|
236 |
|
/* The AppletStub's code and document base is set as follows: |
237 |
|
* The code base is always the URL from where the class data originated |
238 |
|
* (without the package name). |
239 |
|
* If the Applet was deserialized the document base is the location of |
240 |
|
* the serialized instance (usually the ".ser" file) otherwise its the URL |
241 |
|
* from where the class data originated (usually the absolute directory |
242 |
|
* location of the ".class" file). |
243 |
|
*/ |
244 |
|
applet.setStub( |
245 |
|
new DummyAppletStub( |
246 |
|
applet |
247 |
|
.getClass() |
248 |
|
.getProtectionDomain() |
249 |
|
.getCodeSource() |
250 |
|
.getLocation(), |
251 |
|
(beanLocation == null) ? classLocation : beanLocation)); |
252 |
|
|
253 |
|
// Runs the Applet's initialization using an AppletInitializer. |
254 |
|
if (initializer != null) |
255 |
|
{ |
256 |
|
initializer.initialize(applet, beanContext); |
257 |
|
} |
258 |
|
} |
259 |
|
|
260 |
|
// Adds the new bean to its BeanContext. |
261 |
|
if (beanContext != null) |
262 |
|
{ |
263 |
|
beanContext.add(bean); |
264 |
|
} |
265 |
|
|
266 |
|
if (applet != null) |
267 |
|
{ |
268 |
|
|
269 |
|
// Initializes an instantiated (not deserialized) Applet using its own method. |
270 |
|
if (beanLocation == null) |
271 |
|
{ |
272 |
|
applet.init(); |
273 |
|
} |
274 |
|
|
275 |
|
// Runs the Applet's activation using an AppletInitializer. |
276 |
|
if (initializer != null) |
277 |
|
{ |
278 |
|
initializer.activate(applet); |
279 |
|
} |
280 |
|
} |
281 |
|
|
282 |
|
return bean; |
283 |
|
} |
284 |
|
|
285 |
|
/** |
286 |
|
* Returns the Bean as a different class type. |
287 |
|
* This should be used instead of casting to get a new |
288 |
|
* type view of a Bean, because in the future there may |
289 |
|
* be new types of Bean, even Beans spanning multiple |
290 |
|
* Objects. |
291 |
|
* |
292 |
|
* @param bean the Bean to cast. |
293 |
|
* @param newClass the Class to cast it to. |
294 |
|
* |
295 |
|
* @return the Bean as a new view, or if the operation |
296 |
|
* could not be performed, the Bean itself. |
297 |
|
*/ |
298 |
|
public static Object getInstanceOf(Object bean, Class newClass) |
299 |
|
{ |
300 |
|
return bean; |
301 |
|
} |
302 |
|
|
303 |
|
/** |
304 |
|
* Determines whether the Bean can be cast to a different |
305 |
|
* class type. |
306 |
|
* This should be used instead of instanceof to determine |
307 |
|
* a Bean's castability, because in the future there may |
308 |
|
* be new types of Bean, even Beans spanning multiple |
309 |
|
* Objects. |
310 |
|
* |
311 |
|
* @param bean the Bean to cast. |
312 |
|
* @param newClass the Class to cast it to. |
313 |
|
* |
314 |
|
* @return whether the Bean can be cast to the class type |
315 |
|
* in question. |
316 |
|
*/ |
317 |
|
public static boolean isInstanceOf(Object bean, Class newBeanClass) |
318 |
|
{ |
319 |
|
return newBeanClass.isInstance(bean); |
320 |
|
} |
321 |
|
|
322 |
|
/** |
323 |
|
* Returns whether the GUI is available to use. |
324 |
|
* <p>Defaults to true.</p> |
325 |
|
* |
326 |
|
* @return whether the GUI is available to use. |
327 |
|
*/ |
328 |
|
public static boolean isGuiAvailable() |
329 |
|
{ |
330 |
|
return guiAvailable; |
331 |
|
} |
332 |
|
|
333 |
|
/** |
334 |
|
* Returns whether it is design time. Design time means |
335 |
|
* we are in a RAD tool. |
336 |
|
* <p>Defaults to false.</p> |
337 |
|
* |
338 |
|
* @return whether it is design time. |
339 |
|
*/ |
340 |
|
public static boolean isDesignTime() |
341 |
|
{ |
342 |
|
return designTime; |
343 |
|
} |
344 |
|
|
345 |
|
/** |
346 |
|
* Sets whether the GUI is available to use. |
347 |
|
* |
348 |
|
* @param guiAvailable whether the GUI is available to use. |
349 |
|
*/ |
350 |
|
public static void setGuiAvailable(boolean guiAvailable) |
351 |
|
throws SecurityException |
352 |
|
{ |
353 |
|
Beans.guiAvailable = guiAvailable; |
354 |
|
} |
355 |
|
|
356 |
|
/** |
357 |
|
* Sets whether it is design time. Design time means we |
358 |
|
* are in a RAD tool. |
359 |
|
* |
360 |
|
* @param designTime whether it is design time. |
361 |
|
*/ |
362 |
|
public static void setDesignTime(boolean designTime) |
363 |
|
throws SecurityException |
364 |
|
{ |
365 |
|
Beans.designTime = designTime; |
366 |
|
} |
367 |
|
|
|
/** |
|
|
* Set whether it is design time. Design time means we |
|
|
* are in a RAD tool. |
|
|
* |
|
|
* @param designTime whether it is design time. |
|
|
*/ |
|
|
public static void setDesignTime(boolean designTime) |
|
|
throws SecurityException |
|
|
{ |
|
|
Beans.designTime = designTime; |
|
|
} |
|
368 |
} |
} |