jtulach@119
|
1 |
/*
|
jtulach@119
|
2 |
* Copyright (c) 1994, 2011, Oracle and/or its affiliates. All rights reserved.
|
jtulach@119
|
3 |
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
|
jtulach@119
|
4 |
*
|
jtulach@119
|
5 |
* This code is free software; you can redistribute it and/or modify it
|
jtulach@119
|
6 |
* under the terms of the GNU General Public License version 2 only, as
|
jtulach@119
|
7 |
* published by the Free Software Foundation. Oracle designates this
|
jtulach@119
|
8 |
* particular file as subject to the "Classpath" exception as provided
|
jtulach@119
|
9 |
* by Oracle in the LICENSE file that accompanied this code.
|
jtulach@119
|
10 |
*
|
jtulach@119
|
11 |
* This code is distributed in the hope that it will be useful, but WITHOUT
|
jtulach@119
|
12 |
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
|
jtulach@119
|
13 |
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
|
jtulach@119
|
14 |
* version 2 for more details (a copy is included in the LICENSE file that
|
jtulach@119
|
15 |
* accompanied this code).
|
jtulach@119
|
16 |
*
|
jtulach@119
|
17 |
* You should have received a copy of the GNU General Public License version
|
jtulach@119
|
18 |
* 2 along with this work; if not, write to the Free Software Foundation,
|
jtulach@119
|
19 |
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
|
jtulach@119
|
20 |
*
|
jtulach@119
|
21 |
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
|
jtulach@119
|
22 |
* or visit www.oracle.com if you need additional information or have any
|
jtulach@119
|
23 |
* questions.
|
jtulach@119
|
24 |
*/
|
jtulach@119
|
25 |
package java.lang;
|
jtulach@119
|
26 |
|
jtulach@119
|
27 |
import java.io.InputStream;
|
jtulach@119
|
28 |
import java.io.IOException;
|
jtulach@119
|
29 |
import java.net.URL;
|
jtulach@119
|
30 |
import java.util.Enumeration;
|
jaroslav@122
|
31 |
import java.util.NoSuchElementException;
|
jaroslav@232
|
32 |
import org.apidesign.bck2brwsr.core.JavaScriptBody;
|
jtulach@119
|
33 |
|
jtulach@119
|
34 |
/**
|
jtulach@119
|
35 |
* A class loader is an object that is responsible for loading classes. The
|
jtulach@119
|
36 |
* class <tt>ClassLoader</tt> is an abstract class. Given the <a
|
jtulach@119
|
37 |
* href="#name">binary name</a> of a class, a class loader should attempt to
|
jtulach@119
|
38 |
* locate or generate data that constitutes a definition for the class. A
|
jtulach@119
|
39 |
* typical strategy is to transform the name into a file name and then read a
|
jtulach@119
|
40 |
* "class file" of that name from a file system.
|
jtulach@119
|
41 |
*
|
jtulach@119
|
42 |
* <p> Every {@link Class <tt>Class</tt>} object contains a {@link
|
jtulach@119
|
43 |
* Class#getClassLoader() reference} to the <tt>ClassLoader</tt> that defined
|
jtulach@119
|
44 |
* it.
|
jtulach@119
|
45 |
*
|
jtulach@119
|
46 |
* <p> <tt>Class</tt> objects for array classes are not created by class
|
jtulach@119
|
47 |
* loaders, but are created automatically as required by the Java runtime.
|
jtulach@119
|
48 |
* The class loader for an array class, as returned by {@link
|
jtulach@119
|
49 |
* Class#getClassLoader()} is the same as the class loader for its element
|
jtulach@119
|
50 |
* type; if the element type is a primitive type, then the array class has no
|
jtulach@119
|
51 |
* class loader.
|
jtulach@119
|
52 |
*
|
jtulach@119
|
53 |
* <p> Applications implement subclasses of <tt>ClassLoader</tt> in order to
|
jtulach@119
|
54 |
* extend the manner in which the Java virtual machine dynamically loads
|
jtulach@119
|
55 |
* classes.
|
jtulach@119
|
56 |
*
|
jtulach@119
|
57 |
* <p> Class loaders may typically be used by security managers to indicate
|
jtulach@119
|
58 |
* security domains.
|
jtulach@119
|
59 |
*
|
jtulach@119
|
60 |
* <p> The <tt>ClassLoader</tt> class uses a delegation model to search for
|
jtulach@119
|
61 |
* classes and resources. Each instance of <tt>ClassLoader</tt> has an
|
jtulach@119
|
62 |
* associated parent class loader. When requested to find a class or
|
jtulach@119
|
63 |
* resource, a <tt>ClassLoader</tt> instance will delegate the search for the
|
jtulach@119
|
64 |
* class or resource to its parent class loader before attempting to find the
|
jtulach@119
|
65 |
* class or resource itself. The virtual machine's built-in class loader,
|
jtulach@119
|
66 |
* called the "bootstrap class loader", does not itself have a parent but may
|
jtulach@119
|
67 |
* serve as the parent of a <tt>ClassLoader</tt> instance.
|
jtulach@119
|
68 |
*
|
jtulach@119
|
69 |
* <p> Class loaders that support concurrent loading of classes are known as
|
jtulach@119
|
70 |
* <em>parallel capable</em> class loaders and are required to register
|
jtulach@119
|
71 |
* themselves at their class initialization time by invoking the
|
jtulach@119
|
72 |
* {@link
|
jtulach@119
|
73 |
* #registerAsParallelCapable <tt>ClassLoader.registerAsParallelCapable</tt>}
|
jtulach@119
|
74 |
* method. Note that the <tt>ClassLoader</tt> class is registered as parallel
|
jtulach@119
|
75 |
* capable by default. However, its subclasses still need to register themselves
|
jtulach@119
|
76 |
* if they are parallel capable. <br>
|
jtulach@119
|
77 |
* In environments in which the delegation model is not strictly
|
jtulach@119
|
78 |
* hierarchical, class loaders need to be parallel capable, otherwise class
|
jtulach@119
|
79 |
* loading can lead to deadlocks because the loader lock is held for the
|
jtulach@119
|
80 |
* duration of the class loading process (see {@link #loadClass
|
jtulach@119
|
81 |
* <tt>loadClass</tt>} methods).
|
jtulach@119
|
82 |
*
|
jtulach@119
|
83 |
* <p> Normally, the Java virtual machine loads classes from the local file
|
jtulach@119
|
84 |
* system in a platform-dependent manner. For example, on UNIX systems, the
|
jtulach@119
|
85 |
* virtual machine loads classes from the directory defined by the
|
jtulach@119
|
86 |
* <tt>CLASSPATH</tt> environment variable.
|
jtulach@119
|
87 |
*
|
jtulach@119
|
88 |
* <p> However, some classes may not originate from a file; they may originate
|
jtulach@119
|
89 |
* from other sources, such as the network, or they could be constructed by an
|
jtulach@119
|
90 |
* application. The method {@link #defineClass(String, byte[], int, int)
|
jtulach@119
|
91 |
* <tt>defineClass</tt>} converts an array of bytes into an instance of class
|
jtulach@119
|
92 |
* <tt>Class</tt>. Instances of this newly defined class can be created using
|
jtulach@119
|
93 |
* {@link Class#newInstance <tt>Class.newInstance</tt>}.
|
jtulach@119
|
94 |
*
|
jtulach@119
|
95 |
* <p> The methods and constructors of objects created by a class loader may
|
jtulach@119
|
96 |
* reference other classes. To determine the class(es) referred to, the Java
|
jtulach@119
|
97 |
* virtual machine invokes the {@link #loadClass <tt>loadClass</tt>} method of
|
jtulach@119
|
98 |
* the class loader that originally created the class.
|
jtulach@119
|
99 |
*
|
jtulach@119
|
100 |
* <p> For example, an application could create a network class loader to
|
jtulach@119
|
101 |
* download class files from a server. Sample code might look like:
|
jtulach@119
|
102 |
*
|
jtulach@119
|
103 |
* <blockquote><pre>
|
jtulach@119
|
104 |
* ClassLoader loader = new NetworkClassLoader(host, port);
|
jtulach@119
|
105 |
* Object main = loader.loadClass("Main", true).newInstance();
|
jtulach@119
|
106 |
* . . .
|
jtulach@119
|
107 |
* </pre></blockquote>
|
jtulach@119
|
108 |
*
|
jtulach@119
|
109 |
* <p> The network class loader subclass must define the methods {@link
|
jtulach@119
|
110 |
* #findClass <tt>findClass</tt>} and <tt>loadClassData</tt> to load a class
|
jtulach@119
|
111 |
* from the network. Once it has downloaded the bytes that make up the class,
|
jtulach@119
|
112 |
* it should use the method {@link #defineClass <tt>defineClass</tt>} to
|
jtulach@119
|
113 |
* create a class instance. A sample implementation is:
|
jtulach@119
|
114 |
*
|
jtulach@119
|
115 |
* <blockquote><pre>
|
jtulach@119
|
116 |
* class NetworkClassLoader extends ClassLoader {
|
jtulach@119
|
117 |
* String host;
|
jtulach@119
|
118 |
* int port;
|
jtulach@119
|
119 |
*
|
jtulach@119
|
120 |
* public Class findClass(String name) {
|
jtulach@119
|
121 |
* byte[] b = loadClassData(name);
|
jtulach@119
|
122 |
* return defineClass(name, b, 0, b.length);
|
jtulach@119
|
123 |
* }
|
jtulach@119
|
124 |
*
|
jtulach@119
|
125 |
* private byte[] loadClassData(String name) {
|
jtulach@119
|
126 |
* // load the class data from the connection
|
jtulach@119
|
127 |
* . . .
|
jtulach@119
|
128 |
* }
|
jtulach@119
|
129 |
* }
|
jtulach@119
|
130 |
* </pre></blockquote>
|
jtulach@119
|
131 |
*
|
jtulach@119
|
132 |
* <h4> <a name="name">Binary names</a> </h4>
|
jtulach@119
|
133 |
*
|
jtulach@119
|
134 |
* <p> Any class name provided as a {@link String} parameter to methods in
|
jtulach@119
|
135 |
* <tt>ClassLoader</tt> must be a binary name as defined by
|
jtulach@119
|
136 |
* <cite>The Java™ Language Specification</cite>.
|
jtulach@119
|
137 |
*
|
jtulach@119
|
138 |
* <p> Examples of valid class names include:
|
jtulach@119
|
139 |
* <blockquote><pre>
|
jtulach@119
|
140 |
* "java.lang.String"
|
jtulach@119
|
141 |
* "javax.swing.JSpinner$DefaultEditor"
|
jtulach@119
|
142 |
* "java.security.KeyStore$Builder$FileBuilder$1"
|
jtulach@119
|
143 |
* "java.net.URLClassLoader$3$1"
|
jtulach@119
|
144 |
* </pre></blockquote>
|
jtulach@119
|
145 |
*
|
jtulach@119
|
146 |
* @see #resolveClass(Class)
|
jtulach@119
|
147 |
* @since 1.0
|
jtulach@119
|
148 |
*/
|
jtulach@119
|
149 |
public abstract class ClassLoader {
|
jtulach@119
|
150 |
|
jaroslav@232
|
151 |
@JavaScriptBody(args = {}, body = "")
|
jtulach@119
|
152 |
private static native void registerNatives();
|
jtulach@119
|
153 |
static {
|
jtulach@119
|
154 |
registerNatives();
|
jtulach@119
|
155 |
}
|
jtulach@119
|
156 |
|
jtulach@119
|
157 |
// The parent class loader for delegation
|
jtulach@119
|
158 |
// Note: VM hardcoded the offset of this field, thus all new fields
|
jtulach@119
|
159 |
// must be added *after* it.
|
jtulach@119
|
160 |
private final ClassLoader parent;
|
jtulach@119
|
161 |
|
jtulach@119
|
162 |
|
jtulach@119
|
163 |
/**
|
jtulach@119
|
164 |
* Creates a new class loader using the specified parent class loader for
|
jtulach@119
|
165 |
* delegation.
|
jtulach@119
|
166 |
*
|
jtulach@119
|
167 |
* <p> If there is a security manager, its {@link
|
jtulach@119
|
168 |
* SecurityManager#checkCreateClassLoader()
|
jtulach@119
|
169 |
* <tt>checkCreateClassLoader</tt>} method is invoked. This may result in
|
jtulach@119
|
170 |
* a security exception. </p>
|
jtulach@119
|
171 |
*
|
jtulach@119
|
172 |
* @param parent
|
jtulach@119
|
173 |
* The parent class loader
|
jtulach@119
|
174 |
*
|
jtulach@119
|
175 |
* @throws SecurityException
|
jtulach@119
|
176 |
* If a security manager exists and its
|
jtulach@119
|
177 |
* <tt>checkCreateClassLoader</tt> method doesn't allow creation
|
jtulach@119
|
178 |
* of a new class loader.
|
jtulach@119
|
179 |
*
|
jtulach@119
|
180 |
* @since 1.2
|
jtulach@119
|
181 |
*/
|
jtulach@119
|
182 |
protected ClassLoader(ClassLoader parent) {
|
jaroslav@122
|
183 |
throw new SecurityException();
|
jtulach@119
|
184 |
}
|
jtulach@119
|
185 |
|
jtulach@119
|
186 |
/**
|
jtulach@119
|
187 |
* Creates a new class loader using the <tt>ClassLoader</tt> returned by
|
jtulach@119
|
188 |
* the method {@link #getSystemClassLoader()
|
jtulach@119
|
189 |
* <tt>getSystemClassLoader()</tt>} as the parent class loader.
|
jtulach@119
|
190 |
*
|
jtulach@119
|
191 |
* <p> If there is a security manager, its {@link
|
jtulach@119
|
192 |
* SecurityManager#checkCreateClassLoader()
|
jtulach@119
|
193 |
* <tt>checkCreateClassLoader</tt>} method is invoked. This may result in
|
jtulach@119
|
194 |
* a security exception. </p>
|
jtulach@119
|
195 |
*
|
jtulach@119
|
196 |
* @throws SecurityException
|
jtulach@119
|
197 |
* If a security manager exists and its
|
jtulach@119
|
198 |
* <tt>checkCreateClassLoader</tt> method doesn't allow creation
|
jtulach@119
|
199 |
* of a new class loader.
|
jtulach@119
|
200 |
*/
|
jtulach@119
|
201 |
protected ClassLoader() {
|
jaroslav@122
|
202 |
throw new SecurityException();
|
jtulach@119
|
203 |
}
|
jtulach@119
|
204 |
|
jtulach@119
|
205 |
// -- Class --
|
jtulach@119
|
206 |
|
jtulach@119
|
207 |
/**
|
jtulach@119
|
208 |
* Loads the class with the specified <a href="#name">binary name</a>.
|
jtulach@119
|
209 |
* This method searches for classes in the same manner as the {@link
|
jtulach@119
|
210 |
* #loadClass(String, boolean)} method. It is invoked by the Java virtual
|
jtulach@119
|
211 |
* machine to resolve class references. Invoking this method is equivalent
|
jtulach@119
|
212 |
* to invoking {@link #loadClass(String, boolean) <tt>loadClass(name,
|
jtulach@119
|
213 |
* false)</tt>}. </p>
|
jtulach@119
|
214 |
*
|
jtulach@119
|
215 |
* @param name
|
jtulach@119
|
216 |
* The <a href="#name">binary name</a> of the class
|
jtulach@119
|
217 |
*
|
jtulach@119
|
218 |
* @return The resulting <tt>Class</tt> object
|
jtulach@119
|
219 |
*
|
jtulach@119
|
220 |
* @throws ClassNotFoundException
|
jtulach@119
|
221 |
* If the class was not found
|
jtulach@119
|
222 |
*/
|
jtulach@119
|
223 |
public Class<?> loadClass(String name) throws ClassNotFoundException {
|
jtulach@119
|
224 |
return loadClass(name, false);
|
jtulach@119
|
225 |
}
|
jtulach@119
|
226 |
|
jtulach@119
|
227 |
/**
|
jtulach@119
|
228 |
* Loads the class with the specified <a href="#name">binary name</a>. The
|
jtulach@119
|
229 |
* default implementation of this method searches for classes in the
|
jtulach@119
|
230 |
* following order:
|
jtulach@119
|
231 |
*
|
jtulach@119
|
232 |
* <p><ol>
|
jtulach@119
|
233 |
*
|
jtulach@119
|
234 |
* <li><p> Invoke {@link #findLoadedClass(String)} to check if the class
|
jtulach@119
|
235 |
* has already been loaded. </p></li>
|
jtulach@119
|
236 |
*
|
jtulach@119
|
237 |
* <li><p> Invoke the {@link #loadClass(String) <tt>loadClass</tt>} method
|
jtulach@119
|
238 |
* on the parent class loader. If the parent is <tt>null</tt> the class
|
jtulach@119
|
239 |
* loader built-in to the virtual machine is used, instead. </p></li>
|
jtulach@119
|
240 |
*
|
jtulach@119
|
241 |
* <li><p> Invoke the {@link #findClass(String)} method to find the
|
jtulach@119
|
242 |
* class. </p></li>
|
jtulach@119
|
243 |
*
|
jtulach@119
|
244 |
* </ol>
|
jtulach@119
|
245 |
*
|
jtulach@119
|
246 |
* <p> If the class was found using the above steps, and the
|
jtulach@119
|
247 |
* <tt>resolve</tt> flag is true, this method will then invoke the {@link
|
jtulach@119
|
248 |
* #resolveClass(Class)} method on the resulting <tt>Class</tt> object.
|
jtulach@119
|
249 |
*
|
jtulach@119
|
250 |
* <p> Subclasses of <tt>ClassLoader</tt> are encouraged to override {@link
|
jtulach@119
|
251 |
* #findClass(String)}, rather than this method. </p>
|
jtulach@119
|
252 |
*
|
jtulach@119
|
253 |
* <p> Unless overridden, this method synchronizes on the result of
|
jtulach@119
|
254 |
* {@link #getClassLoadingLock <tt>getClassLoadingLock</tt>} method
|
jtulach@119
|
255 |
* during the entire class loading process.
|
jtulach@119
|
256 |
*
|
jtulach@119
|
257 |
* @param name
|
jtulach@119
|
258 |
* The <a href="#name">binary name</a> of the class
|
jtulach@119
|
259 |
*
|
jtulach@119
|
260 |
* @param resolve
|
jtulach@119
|
261 |
* If <tt>true</tt> then resolve the class
|
jtulach@119
|
262 |
*
|
jtulach@119
|
263 |
* @return The resulting <tt>Class</tt> object
|
jtulach@119
|
264 |
*
|
jtulach@119
|
265 |
* @throws ClassNotFoundException
|
jtulach@119
|
266 |
* If the class could not be found
|
jtulach@119
|
267 |
*/
|
jtulach@119
|
268 |
protected Class<?> loadClass(String name, boolean resolve)
|
jtulach@119
|
269 |
throws ClassNotFoundException
|
jtulach@119
|
270 |
{
|
jtulach@119
|
271 |
synchronized (getClassLoadingLock(name)) {
|
jtulach@119
|
272 |
// First, check if the class has already been loaded
|
jtulach@119
|
273 |
Class c = findLoadedClass(name);
|
jtulach@119
|
274 |
if (c == null) {
|
jtulach@119
|
275 |
try {
|
jtulach@119
|
276 |
if (parent != null) {
|
jtulach@119
|
277 |
c = parent.loadClass(name, false);
|
jtulach@119
|
278 |
} else {
|
jtulach@119
|
279 |
c = findBootstrapClassOrNull(name);
|
jtulach@119
|
280 |
}
|
jtulach@119
|
281 |
} catch (ClassNotFoundException e) {
|
jtulach@119
|
282 |
// ClassNotFoundException thrown if class not found
|
jtulach@119
|
283 |
// from the non-null parent class loader
|
jtulach@119
|
284 |
}
|
jtulach@119
|
285 |
|
jtulach@119
|
286 |
if (c == null) {
|
jtulach@119
|
287 |
// If still not found, then invoke findClass in order
|
jtulach@119
|
288 |
// to find the class.
|
jtulach@119
|
289 |
c = findClass(name);
|
jtulach@119
|
290 |
|
jaroslav@122
|
291 |
// // this is the defining class loader; record the stats
|
jaroslav@122
|
292 |
// sun.misc.PerfCounter.getParentDelegationTime().addTime(t1 - t0);
|
jaroslav@122
|
293 |
// sun.misc.PerfCounter.getFindClassTime().addElapsedTimeFrom(t1);
|
jaroslav@122
|
294 |
// sun.misc.PerfCounter.getFindClasses().increment();
|
jtulach@119
|
295 |
}
|
jtulach@119
|
296 |
}
|
jtulach@119
|
297 |
if (resolve) {
|
jtulach@119
|
298 |
resolveClass(c);
|
jtulach@119
|
299 |
}
|
jtulach@119
|
300 |
return c;
|
jtulach@119
|
301 |
}
|
jtulach@119
|
302 |
}
|
jtulach@119
|
303 |
|
jtulach@119
|
304 |
/**
|
jtulach@119
|
305 |
* Returns the lock object for class loading operations.
|
jtulach@119
|
306 |
* For backward compatibility, the default implementation of this method
|
jtulach@119
|
307 |
* behaves as follows. If this ClassLoader object is registered as
|
jtulach@119
|
308 |
* parallel capable, the method returns a dedicated object associated
|
jtulach@119
|
309 |
* with the specified class name. Otherwise, the method returns this
|
jtulach@119
|
310 |
* ClassLoader object. </p>
|
jtulach@119
|
311 |
*
|
jtulach@119
|
312 |
* @param className
|
jtulach@119
|
313 |
* The name of the to-be-loaded class
|
jtulach@119
|
314 |
*
|
jtulach@119
|
315 |
* @return the lock for class loading operations
|
jtulach@119
|
316 |
*
|
jtulach@119
|
317 |
* @throws NullPointerException
|
jtulach@119
|
318 |
* If registered as parallel capable and <tt>className</tt> is null
|
jtulach@119
|
319 |
*
|
jtulach@119
|
320 |
* @see #loadClass(String, boolean)
|
jtulach@119
|
321 |
*
|
jtulach@119
|
322 |
* @since 1.7
|
jtulach@119
|
323 |
*/
|
jtulach@119
|
324 |
protected Object getClassLoadingLock(String className) {
|
jtulach@119
|
325 |
Object lock = this;
|
jtulach@119
|
326 |
return lock;
|
jtulach@119
|
327 |
}
|
jtulach@119
|
328 |
|
jtulach@119
|
329 |
/**
|
jtulach@119
|
330 |
* Finds the class with the specified <a href="#name">binary name</a>.
|
jtulach@119
|
331 |
* This method should be overridden by class loader implementations that
|
jtulach@119
|
332 |
* follow the delegation model for loading classes, and will be invoked by
|
jtulach@119
|
333 |
* the {@link #loadClass <tt>loadClass</tt>} method after checking the
|
jtulach@119
|
334 |
* parent class loader for the requested class. The default implementation
|
jtulach@119
|
335 |
* throws a <tt>ClassNotFoundException</tt>. </p>
|
jtulach@119
|
336 |
*
|
jtulach@119
|
337 |
* @param name
|
jtulach@119
|
338 |
* The <a href="#name">binary name</a> of the class
|
jtulach@119
|
339 |
*
|
jtulach@119
|
340 |
* @return The resulting <tt>Class</tt> object
|
jtulach@119
|
341 |
*
|
jtulach@119
|
342 |
* @throws ClassNotFoundException
|
jtulach@119
|
343 |
* If the class could not be found
|
jtulach@119
|
344 |
*
|
jtulach@119
|
345 |
* @since 1.2
|
jtulach@119
|
346 |
*/
|
jtulach@119
|
347 |
protected Class<?> findClass(String name) throws ClassNotFoundException {
|
jtulach@119
|
348 |
throw new ClassNotFoundException(name);
|
jtulach@119
|
349 |
}
|
jtulach@119
|
350 |
|
jtulach@119
|
351 |
/**
|
jtulach@119
|
352 |
* Converts an array of bytes into an instance of class <tt>Class</tt>.
|
jtulach@119
|
353 |
* Before the <tt>Class</tt> can be used it must be resolved. This method
|
jtulach@119
|
354 |
* is deprecated in favor of the version that takes a <a
|
jtulach@119
|
355 |
* href="#name">binary name</a> as its first argument, and is more secure.
|
jtulach@119
|
356 |
*
|
jtulach@119
|
357 |
* @param b
|
jtulach@119
|
358 |
* The bytes that make up the class data. The bytes in positions
|
jtulach@119
|
359 |
* <tt>off</tt> through <tt>off+len-1</tt> should have the format
|
jtulach@119
|
360 |
* of a valid class file as defined by
|
jtulach@119
|
361 |
* <cite>The Java™ Virtual Machine Specification</cite>.
|
jtulach@119
|
362 |
*
|
jtulach@119
|
363 |
* @param off
|
jtulach@119
|
364 |
* The start offset in <tt>b</tt> of the class data
|
jtulach@119
|
365 |
*
|
jtulach@119
|
366 |
* @param len
|
jtulach@119
|
367 |
* The length of the class data
|
jtulach@119
|
368 |
*
|
jtulach@119
|
369 |
* @return The <tt>Class</tt> object that was created from the specified
|
jtulach@119
|
370 |
* class data
|
jtulach@119
|
371 |
*
|
jtulach@119
|
372 |
* @throws ClassFormatError
|
jtulach@119
|
373 |
* If the data did not contain a valid class
|
jtulach@119
|
374 |
*
|
jtulach@119
|
375 |
* @throws IndexOutOfBoundsException
|
jtulach@119
|
376 |
* If either <tt>off</tt> or <tt>len</tt> is negative, or if
|
jtulach@119
|
377 |
* <tt>off+len</tt> is greater than <tt>b.length</tt>.
|
jtulach@119
|
378 |
*
|
jtulach@119
|
379 |
* @throws SecurityException
|
jtulach@119
|
380 |
* If an attempt is made to add this class to a package that
|
jtulach@119
|
381 |
* contains classes that were signed by a different set of
|
jtulach@119
|
382 |
* certificates than this class, or if an attempt is made
|
jtulach@119
|
383 |
* to define a class in a package with a fully-qualified name
|
jtulach@119
|
384 |
* that starts with "{@code java.}".
|
jtulach@119
|
385 |
*
|
jtulach@119
|
386 |
* @see #loadClass(String, boolean)
|
jtulach@119
|
387 |
* @see #resolveClass(Class)
|
jtulach@119
|
388 |
*
|
jtulach@119
|
389 |
* @deprecated Replaced by {@link #defineClass(String, byte[], int, int)
|
jtulach@119
|
390 |
* defineClass(String, byte[], int, int)}
|
jtulach@119
|
391 |
*/
|
jtulach@119
|
392 |
@Deprecated
|
jtulach@119
|
393 |
protected final Class<?> defineClass(byte[] b, int off, int len)
|
jtulach@119
|
394 |
throws ClassFormatError
|
jtulach@119
|
395 |
{
|
jaroslav@122
|
396 |
throw new SecurityException();
|
jtulach@119
|
397 |
}
|
jtulach@119
|
398 |
|
jtulach@119
|
399 |
/**
|
jtulach@119
|
400 |
* Converts an array of bytes into an instance of class <tt>Class</tt>.
|
jtulach@119
|
401 |
* Before the <tt>Class</tt> can be used it must be resolved.
|
jtulach@119
|
402 |
*
|
jtulach@119
|
403 |
* <p> This method assigns a default {@link java.security.ProtectionDomain
|
jtulach@119
|
404 |
* <tt>ProtectionDomain</tt>} to the newly defined class. The
|
jtulach@119
|
405 |
* <tt>ProtectionDomain</tt> is effectively granted the same set of
|
jtulach@119
|
406 |
* permissions returned when {@link
|
jtulach@119
|
407 |
* java.security.Policy#getPermissions(java.security.CodeSource)
|
jtulach@119
|
408 |
* <tt>Policy.getPolicy().getPermissions(new CodeSource(null, null))</tt>}
|
jtulach@119
|
409 |
* is invoked. The default domain is created on the first invocation of
|
jtulach@119
|
410 |
* {@link #defineClass(String, byte[], int, int) <tt>defineClass</tt>},
|
jtulach@119
|
411 |
* and re-used on subsequent invocations.
|
jtulach@119
|
412 |
*
|
jtulach@119
|
413 |
* <p> To assign a specific <tt>ProtectionDomain</tt> to the class, use
|
jtulach@119
|
414 |
* the {@link #defineClass(String, byte[], int, int,
|
jtulach@119
|
415 |
* java.security.ProtectionDomain) <tt>defineClass</tt>} method that takes a
|
jtulach@119
|
416 |
* <tt>ProtectionDomain</tt> as one of its arguments. </p>
|
jtulach@119
|
417 |
*
|
jtulach@119
|
418 |
* @param name
|
jtulach@119
|
419 |
* The expected <a href="#name">binary name</a> of the class, or
|
jtulach@119
|
420 |
* <tt>null</tt> if not known
|
jtulach@119
|
421 |
*
|
jtulach@119
|
422 |
* @param b
|
jtulach@119
|
423 |
* The bytes that make up the class data. The bytes in positions
|
jtulach@119
|
424 |
* <tt>off</tt> through <tt>off+len-1</tt> should have the format
|
jtulach@119
|
425 |
* of a valid class file as defined by
|
jtulach@119
|
426 |
* <cite>The Java™ Virtual Machine Specification</cite>.
|
jtulach@119
|
427 |
*
|
jtulach@119
|
428 |
* @param off
|
jtulach@119
|
429 |
* The start offset in <tt>b</tt> of the class data
|
jtulach@119
|
430 |
*
|
jtulach@119
|
431 |
* @param len
|
jtulach@119
|
432 |
* The length of the class data
|
jtulach@119
|
433 |
*
|
jtulach@119
|
434 |
* @return The <tt>Class</tt> object that was created from the specified
|
jtulach@119
|
435 |
* class data.
|
jtulach@119
|
436 |
*
|
jtulach@119
|
437 |
* @throws ClassFormatError
|
jtulach@119
|
438 |
* If the data did not contain a valid class
|
jtulach@119
|
439 |
*
|
jtulach@119
|
440 |
* @throws IndexOutOfBoundsException
|
jtulach@119
|
441 |
* If either <tt>off</tt> or <tt>len</tt> is negative, or if
|
jtulach@119
|
442 |
* <tt>off+len</tt> is greater than <tt>b.length</tt>.
|
jtulach@119
|
443 |
*
|
jtulach@119
|
444 |
* @throws SecurityException
|
jtulach@119
|
445 |
* If an attempt is made to add this class to a package that
|
jtulach@119
|
446 |
* contains classes that were signed by a different set of
|
jtulach@119
|
447 |
* certificates than this class (which is unsigned), or if
|
jtulach@119
|
448 |
* <tt>name</tt> begins with "<tt>java.</tt>".
|
jtulach@119
|
449 |
*
|
jtulach@119
|
450 |
* @see #loadClass(String, boolean)
|
jtulach@119
|
451 |
* @see #resolveClass(Class)
|
jtulach@119
|
452 |
* @see java.security.CodeSource
|
jtulach@119
|
453 |
* @see java.security.SecureClassLoader
|
jtulach@119
|
454 |
*
|
jtulach@119
|
455 |
* @since 1.1
|
jtulach@119
|
456 |
*/
|
jtulach@119
|
457 |
protected final Class<?> defineClass(String name, byte[] b, int off, int len)
|
jtulach@119
|
458 |
throws ClassFormatError
|
jtulach@119
|
459 |
{
|
jaroslav@122
|
460 |
throw new SecurityException();
|
jtulach@119
|
461 |
}
|
jtulach@119
|
462 |
|
jtulach@119
|
463 |
/**
|
jtulach@119
|
464 |
* Links the specified class. This (misleadingly named) method may be
|
jtulach@119
|
465 |
* used by a class loader to link a class. If the class <tt>c</tt> has
|
jtulach@119
|
466 |
* already been linked, then this method simply returns. Otherwise, the
|
jtulach@119
|
467 |
* class is linked as described in the "Execution" chapter of
|
jtulach@119
|
468 |
* <cite>The Java™ Language Specification</cite>.
|
jtulach@119
|
469 |
* </p>
|
jtulach@119
|
470 |
*
|
jtulach@119
|
471 |
* @param c
|
jtulach@119
|
472 |
* The class to link
|
jtulach@119
|
473 |
*
|
jtulach@119
|
474 |
* @throws NullPointerException
|
jtulach@119
|
475 |
* If <tt>c</tt> is <tt>null</tt>.
|
jtulach@119
|
476 |
*
|
jtulach@119
|
477 |
* @see #defineClass(String, byte[], int, int)
|
jtulach@119
|
478 |
*/
|
jtulach@119
|
479 |
protected final void resolveClass(Class<?> c) {
|
jtulach@119
|
480 |
resolveClass0(c);
|
jtulach@119
|
481 |
}
|
jtulach@119
|
482 |
|
jtulach@119
|
483 |
private native void resolveClass0(Class c);
|
jtulach@119
|
484 |
|
jtulach@119
|
485 |
|
jtulach@119
|
486 |
/**
|
jtulach@119
|
487 |
* Returns the class with the given <a href="#name">binary name</a> if this
|
jtulach@119
|
488 |
* loader has been recorded by the Java virtual machine as an initiating
|
jtulach@119
|
489 |
* loader of a class with that <a href="#name">binary name</a>. Otherwise
|
jtulach@119
|
490 |
* <tt>null</tt> is returned. </p>
|
jtulach@119
|
491 |
*
|
jtulach@119
|
492 |
* @param name
|
jtulach@119
|
493 |
* The <a href="#name">binary name</a> of the class
|
jtulach@119
|
494 |
*
|
jtulach@119
|
495 |
* @return The <tt>Class</tt> object, or <tt>null</tt> if the class has
|
jtulach@119
|
496 |
* not been loaded
|
jtulach@119
|
497 |
*
|
jtulach@119
|
498 |
* @since 1.1
|
jtulach@119
|
499 |
*/
|
jtulach@119
|
500 |
protected final Class<?> findLoadedClass(String name) {
|
jtulach@119
|
501 |
if (!checkName(name))
|
jtulach@119
|
502 |
return null;
|
jtulach@119
|
503 |
return findLoadedClass0(name);
|
jtulach@119
|
504 |
}
|
jtulach@119
|
505 |
|
jtulach@119
|
506 |
private native final Class findLoadedClass0(String name);
|
jtulach@119
|
507 |
|
jtulach@119
|
508 |
/**
|
jtulach@119
|
509 |
* Sets the signers of a class. This should be invoked after defining a
|
jtulach@119
|
510 |
* class. </p>
|
jtulach@119
|
511 |
*
|
jtulach@119
|
512 |
* @param c
|
jtulach@119
|
513 |
* The <tt>Class</tt> object
|
jtulach@119
|
514 |
*
|
jtulach@119
|
515 |
* @param signers
|
jtulach@119
|
516 |
* The signers for the class
|
jtulach@119
|
517 |
*
|
jtulach@119
|
518 |
* @since 1.1
|
jtulach@119
|
519 |
*/
|
jtulach@119
|
520 |
protected final void setSigners(Class<?> c, Object[] signers) {
|
jaroslav@122
|
521 |
//c.setSigners(signers);
|
jaroslav@122
|
522 |
throw new UnsupportedOperationException();
|
jtulach@119
|
523 |
}
|
jtulach@119
|
524 |
|
jtulach@119
|
525 |
|
jtulach@119
|
526 |
// -- Resource --
|
jtulach@119
|
527 |
|
jtulach@119
|
528 |
/**
|
jtulach@119
|
529 |
* Finds the resource with the given name. A resource is some data
|
jtulach@119
|
530 |
* (images, audio, text, etc) that can be accessed by class code in a way
|
jtulach@119
|
531 |
* that is independent of the location of the code.
|
jtulach@119
|
532 |
*
|
jtulach@119
|
533 |
* <p> The name of a resource is a '<tt>/</tt>'-separated path name that
|
jtulach@119
|
534 |
* identifies the resource.
|
jtulach@119
|
535 |
*
|
jtulach@119
|
536 |
* <p> This method will first search the parent class loader for the
|
jtulach@119
|
537 |
* resource; if the parent is <tt>null</tt> the path of the class loader
|
jtulach@119
|
538 |
* built-in to the virtual machine is searched. That failing, this method
|
jtulach@119
|
539 |
* will invoke {@link #findResource(String)} to find the resource. </p>
|
jtulach@119
|
540 |
*
|
jtulach@119
|
541 |
* @param name
|
jtulach@119
|
542 |
* The resource name
|
jtulach@119
|
543 |
*
|
jtulach@119
|
544 |
* @return A <tt>URL</tt> object for reading the resource, or
|
jtulach@119
|
545 |
* <tt>null</tt> if the resource could not be found or the invoker
|
jtulach@119
|
546 |
* doesn't have adequate privileges to get the resource.
|
jtulach@119
|
547 |
*
|
jtulach@119
|
548 |
* @since 1.1
|
jtulach@119
|
549 |
*/
|
jtulach@119
|
550 |
public URL getResource(String name) {
|
jtulach@119
|
551 |
URL url;
|
jtulach@119
|
552 |
if (parent != null) {
|
jtulach@119
|
553 |
url = parent.getResource(name);
|
jtulach@119
|
554 |
} else {
|
jtulach@119
|
555 |
url = getBootstrapResource(name);
|
jtulach@119
|
556 |
}
|
jtulach@119
|
557 |
if (url == null) {
|
jtulach@119
|
558 |
url = findResource(name);
|
jtulach@119
|
559 |
}
|
jtulach@119
|
560 |
return url;
|
jtulach@119
|
561 |
}
|
jtulach@119
|
562 |
|
jtulach@119
|
563 |
/**
|
jtulach@119
|
564 |
* Finds all the resources with the given name. A resource is some data
|
jtulach@119
|
565 |
* (images, audio, text, etc) that can be accessed by class code in a way
|
jtulach@119
|
566 |
* that is independent of the location of the code.
|
jtulach@119
|
567 |
*
|
jtulach@119
|
568 |
* <p>The name of a resource is a <tt>/</tt>-separated path name that
|
jtulach@119
|
569 |
* identifies the resource.
|
jtulach@119
|
570 |
*
|
jtulach@119
|
571 |
* <p> The search order is described in the documentation for {@link
|
jtulach@119
|
572 |
* #getResource(String)}. </p>
|
jtulach@119
|
573 |
*
|
jtulach@119
|
574 |
* @param name
|
jtulach@119
|
575 |
* The resource name
|
jtulach@119
|
576 |
*
|
jtulach@119
|
577 |
* @return An enumeration of {@link java.net.URL <tt>URL</tt>} objects for
|
jtulach@119
|
578 |
* the resource. If no resources could be found, the enumeration
|
jtulach@119
|
579 |
* will be empty. Resources that the class loader doesn't have
|
jtulach@119
|
580 |
* access to will not be in the enumeration.
|
jtulach@119
|
581 |
*
|
jtulach@119
|
582 |
* @throws IOException
|
jtulach@119
|
583 |
* If I/O errors occur
|
jtulach@119
|
584 |
*
|
jtulach@119
|
585 |
* @see #findResources(String)
|
jtulach@119
|
586 |
*
|
jtulach@119
|
587 |
* @since 1.2
|
jtulach@119
|
588 |
*/
|
jtulach@119
|
589 |
public Enumeration<URL> getResources(String name) throws IOException {
|
jtulach@119
|
590 |
Enumeration[] tmp = new Enumeration[2];
|
jtulach@119
|
591 |
if (parent != null) {
|
jtulach@119
|
592 |
tmp[0] = parent.getResources(name);
|
jtulach@119
|
593 |
} else {
|
jtulach@119
|
594 |
tmp[0] = getBootstrapResources(name);
|
jtulach@119
|
595 |
}
|
jtulach@119
|
596 |
tmp[1] = findResources(name);
|
jtulach@119
|
597 |
|
jaroslav@122
|
598 |
return new CompoundEnumeration(tmp);
|
jtulach@119
|
599 |
}
|
jtulach@119
|
600 |
|
jtulach@119
|
601 |
/**
|
jtulach@119
|
602 |
* Finds the resource with the given name. Class loader implementations
|
jtulach@119
|
603 |
* should override this method to specify where to find resources. </p>
|
jtulach@119
|
604 |
*
|
jtulach@119
|
605 |
* @param name
|
jtulach@119
|
606 |
* The resource name
|
jtulach@119
|
607 |
*
|
jtulach@119
|
608 |
* @return A <tt>URL</tt> object for reading the resource, or
|
jtulach@119
|
609 |
* <tt>null</tt> if the resource could not be found
|
jtulach@119
|
610 |
*
|
jtulach@119
|
611 |
* @since 1.2
|
jtulach@119
|
612 |
*/
|
jtulach@119
|
613 |
protected URL findResource(String name) {
|
jtulach@119
|
614 |
return null;
|
jtulach@119
|
615 |
}
|
jtulach@119
|
616 |
|
jtulach@119
|
617 |
/**
|
jtulach@119
|
618 |
* Returns an enumeration of {@link java.net.URL <tt>URL</tt>} objects
|
jtulach@119
|
619 |
* representing all the resources with the given name. Class loader
|
jtulach@119
|
620 |
* implementations should override this method to specify where to load
|
jtulach@119
|
621 |
* resources from. </p>
|
jtulach@119
|
622 |
*
|
jtulach@119
|
623 |
* @param name
|
jtulach@119
|
624 |
* The resource name
|
jtulach@119
|
625 |
*
|
jtulach@119
|
626 |
* @return An enumeration of {@link java.net.URL <tt>URL</tt>} objects for
|
jtulach@119
|
627 |
* the resources
|
jtulach@119
|
628 |
*
|
jtulach@119
|
629 |
* @throws IOException
|
jtulach@119
|
630 |
* If I/O errors occur
|
jtulach@119
|
631 |
*
|
jtulach@119
|
632 |
* @since 1.2
|
jtulach@119
|
633 |
*/
|
jtulach@119
|
634 |
protected Enumeration<URL> findResources(String name) throws IOException {
|
jaroslav@122
|
635 |
return new CompoundEnumeration(new Enumeration[0]);
|
jtulach@119
|
636 |
}
|
jtulach@119
|
637 |
|
jtulach@119
|
638 |
// index 0: java.lang.ClassLoader.class
|
jtulach@119
|
639 |
// index 1: the immediate caller of index 0.
|
jtulach@119
|
640 |
// index 2: the immediate caller of index 1.
|
jtulach@119
|
641 |
private static native Class<? extends ClassLoader> getCaller(int index);
|
jtulach@119
|
642 |
|
jtulach@119
|
643 |
/**
|
jtulach@119
|
644 |
* Registers the caller as parallel capable.</p>
|
jtulach@119
|
645 |
* The registration succeeds if and only if all of the following
|
jtulach@119
|
646 |
* conditions are met: <br>
|
jtulach@119
|
647 |
* 1. no instance of the caller has been created</p>
|
jtulach@119
|
648 |
* 2. all of the super classes (except class Object) of the caller are
|
jtulach@119
|
649 |
* registered as parallel capable</p>
|
jtulach@119
|
650 |
* Note that once a class loader is registered as parallel capable, there
|
jtulach@119
|
651 |
* is no way to change it back. </p>
|
jtulach@119
|
652 |
*
|
jtulach@119
|
653 |
* @return true if the caller is successfully registered as
|
jtulach@119
|
654 |
* parallel capable and false if otherwise.
|
jtulach@119
|
655 |
*
|
jtulach@119
|
656 |
* @since 1.7
|
jtulach@119
|
657 |
*/
|
jaroslav@122
|
658 |
// protected static boolean registerAsParallelCapable() {
|
jaroslav@122
|
659 |
// return false;
|
jaroslav@122
|
660 |
// }
|
jtulach@119
|
661 |
|
jtulach@119
|
662 |
/**
|
jtulach@119
|
663 |
* Find a resource of the specified name from the search path used to load
|
jtulach@119
|
664 |
* classes. This method locates the resource through the system class
|
jtulach@119
|
665 |
* loader (see {@link #getSystemClassLoader()}). </p>
|
jtulach@119
|
666 |
*
|
jtulach@119
|
667 |
* @param name
|
jtulach@119
|
668 |
* The resource name
|
jtulach@119
|
669 |
*
|
jtulach@119
|
670 |
* @return A {@link java.net.URL <tt>URL</tt>} object for reading the
|
jtulach@119
|
671 |
* resource, or <tt>null</tt> if the resource could not be found
|
jtulach@119
|
672 |
*
|
jtulach@119
|
673 |
* @since 1.1
|
jtulach@119
|
674 |
*/
|
jtulach@119
|
675 |
public static URL getSystemResource(String name) {
|
jtulach@119
|
676 |
ClassLoader system = getSystemClassLoader();
|
jtulach@119
|
677 |
if (system == null) {
|
jtulach@119
|
678 |
return getBootstrapResource(name);
|
jtulach@119
|
679 |
}
|
jtulach@119
|
680 |
return system.getResource(name);
|
jtulach@119
|
681 |
}
|
jtulach@119
|
682 |
|
jtulach@119
|
683 |
/**
|
jtulach@119
|
684 |
* Finds all resources of the specified name from the search path used to
|
jtulach@119
|
685 |
* load classes. The resources thus found are returned as an
|
jtulach@119
|
686 |
* {@link java.util.Enumeration <tt>Enumeration</tt>} of {@link
|
jtulach@119
|
687 |
* java.net.URL <tt>URL</tt>} objects.
|
jtulach@119
|
688 |
*
|
jtulach@119
|
689 |
* <p> The search order is described in the documentation for {@link
|
jtulach@119
|
690 |
* #getSystemResource(String)}. </p>
|
jtulach@119
|
691 |
*
|
jtulach@119
|
692 |
* @param name
|
jtulach@119
|
693 |
* The resource name
|
jtulach@119
|
694 |
*
|
jtulach@119
|
695 |
* @return An enumeration of resource {@link java.net.URL <tt>URL</tt>}
|
jtulach@119
|
696 |
* objects
|
jtulach@119
|
697 |
*
|
jtulach@119
|
698 |
* @throws IOException
|
jtulach@119
|
699 |
* If I/O errors occur
|
jtulach@119
|
700 |
|
jtulach@119
|
701 |
* @since 1.2
|
jtulach@119
|
702 |
*/
|
jtulach@119
|
703 |
public static Enumeration<URL> getSystemResources(String name)
|
jtulach@119
|
704 |
throws IOException
|
jtulach@119
|
705 |
{
|
jtulach@119
|
706 |
ClassLoader system = getSystemClassLoader();
|
jtulach@119
|
707 |
if (system == null) {
|
jtulach@119
|
708 |
return getBootstrapResources(name);
|
jtulach@119
|
709 |
}
|
jtulach@119
|
710 |
return system.getResources(name);
|
jtulach@119
|
711 |
}
|
jtulach@119
|
712 |
|
jtulach@119
|
713 |
|
jtulach@119
|
714 |
|
jtulach@119
|
715 |
/**
|
jtulach@119
|
716 |
* Returns an input stream for reading the specified resource.
|
jtulach@119
|
717 |
*
|
jtulach@119
|
718 |
* <p> The search order is described in the documentation for {@link
|
jtulach@119
|
719 |
* #getResource(String)}. </p>
|
jtulach@119
|
720 |
*
|
jtulach@119
|
721 |
* @param name
|
jtulach@119
|
722 |
* The resource name
|
jtulach@119
|
723 |
*
|
jtulach@119
|
724 |
* @return An input stream for reading the resource, or <tt>null</tt>
|
jtulach@119
|
725 |
* if the resource could not be found
|
jtulach@119
|
726 |
*
|
jtulach@119
|
727 |
* @since 1.1
|
jtulach@119
|
728 |
*/
|
jtulach@119
|
729 |
public InputStream getResourceAsStream(String name) {
|
jtulach@119
|
730 |
URL url = getResource(name);
|
jtulach@119
|
731 |
try {
|
jtulach@119
|
732 |
return url != null ? url.openStream() : null;
|
jtulach@119
|
733 |
} catch (IOException e) {
|
jtulach@119
|
734 |
return null;
|
jtulach@119
|
735 |
}
|
jtulach@119
|
736 |
}
|
jtulach@119
|
737 |
|
jtulach@119
|
738 |
/**
|
jtulach@119
|
739 |
* Open for reading, a resource of the specified name from the search path
|
jtulach@119
|
740 |
* used to load classes. This method locates the resource through the
|
jtulach@119
|
741 |
* system class loader (see {@link #getSystemClassLoader()}). </p>
|
jtulach@119
|
742 |
*
|
jtulach@119
|
743 |
* @param name
|
jtulach@119
|
744 |
* The resource name
|
jtulach@119
|
745 |
*
|
jtulach@119
|
746 |
* @return An input stream for reading the resource, or <tt>null</tt>
|
jtulach@119
|
747 |
* if the resource could not be found
|
jtulach@119
|
748 |
*
|
jtulach@119
|
749 |
* @since 1.1
|
jtulach@119
|
750 |
*/
|
jtulach@119
|
751 |
public static InputStream getSystemResourceAsStream(String name) {
|
jtulach@119
|
752 |
URL url = getSystemResource(name);
|
jtulach@119
|
753 |
try {
|
jtulach@119
|
754 |
return url != null ? url.openStream() : null;
|
jtulach@119
|
755 |
} catch (IOException e) {
|
jtulach@119
|
756 |
return null;
|
jtulach@119
|
757 |
}
|
jtulach@119
|
758 |
}
|
jtulach@119
|
759 |
|
jtulach@119
|
760 |
|
jtulach@119
|
761 |
// -- Hierarchy --
|
jtulach@119
|
762 |
|
jtulach@119
|
763 |
/**
|
jtulach@119
|
764 |
* Returns the parent class loader for delegation. Some implementations may
|
jtulach@119
|
765 |
* use <tt>null</tt> to represent the bootstrap class loader. This method
|
jtulach@119
|
766 |
* will return <tt>null</tt> in such implementations if this class loader's
|
jtulach@119
|
767 |
* parent is the bootstrap class loader.
|
jtulach@119
|
768 |
*
|
jtulach@119
|
769 |
* <p> If a security manager is present, and the invoker's class loader is
|
jtulach@119
|
770 |
* not <tt>null</tt> and is not an ancestor of this class loader, then this
|
jtulach@119
|
771 |
* method invokes the security manager's {@link
|
jtulach@119
|
772 |
* SecurityManager#checkPermission(java.security.Permission)
|
jtulach@119
|
773 |
* <tt>checkPermission</tt>} method with a {@link
|
jtulach@119
|
774 |
* RuntimePermission#RuntimePermission(String)
|
jtulach@119
|
775 |
* <tt>RuntimePermission("getClassLoader")</tt>} permission to verify
|
jtulach@119
|
776 |
* access to the parent class loader is permitted. If not, a
|
jtulach@119
|
777 |
* <tt>SecurityException</tt> will be thrown. </p>
|
jtulach@119
|
778 |
*
|
jtulach@119
|
779 |
* @return The parent <tt>ClassLoader</tt>
|
jtulach@119
|
780 |
*
|
jtulach@119
|
781 |
* @throws SecurityException
|
jtulach@119
|
782 |
* If a security manager exists and its <tt>checkPermission</tt>
|
jtulach@119
|
783 |
* method doesn't allow access to this class loader's parent class
|
jtulach@119
|
784 |
* loader.
|
jtulach@119
|
785 |
*
|
jtulach@119
|
786 |
* @since 1.2
|
jtulach@119
|
787 |
*/
|
jtulach@119
|
788 |
public final ClassLoader getParent() {
|
jaroslav@122
|
789 |
throw new SecurityException();
|
jtulach@119
|
790 |
}
|
jtulach@119
|
791 |
|
jtulach@119
|
792 |
/**
|
jtulach@119
|
793 |
* Returns the system class loader for delegation. This is the default
|
jtulach@119
|
794 |
* delegation parent for new <tt>ClassLoader</tt> instances, and is
|
jtulach@119
|
795 |
* typically the class loader used to start the application.
|
jtulach@119
|
796 |
*
|
jtulach@119
|
797 |
* <p> This method is first invoked early in the runtime's startup
|
jtulach@119
|
798 |
* sequence, at which point it creates the system class loader and sets it
|
jtulach@119
|
799 |
* as the context class loader of the invoking <tt>Thread</tt>.
|
jtulach@119
|
800 |
*
|
jtulach@119
|
801 |
* <p> The default system class loader is an implementation-dependent
|
jtulach@119
|
802 |
* instance of this class.
|
jtulach@119
|
803 |
*
|
jtulach@119
|
804 |
* <p> If the system property "<tt>java.system.class.loader</tt>" is defined
|
jtulach@119
|
805 |
* when this method is first invoked then the value of that property is
|
jtulach@119
|
806 |
* taken to be the name of a class that will be returned as the system
|
jtulach@119
|
807 |
* class loader. The class is loaded using the default system class loader
|
jtulach@119
|
808 |
* and must define a public constructor that takes a single parameter of
|
jtulach@119
|
809 |
* type <tt>ClassLoader</tt> which is used as the delegation parent. An
|
jtulach@119
|
810 |
* instance is then created using this constructor with the default system
|
jtulach@119
|
811 |
* class loader as the parameter. The resulting class loader is defined
|
jtulach@119
|
812 |
* to be the system class loader.
|
jtulach@119
|
813 |
*
|
jtulach@119
|
814 |
* <p> If a security manager is present, and the invoker's class loader is
|
jtulach@119
|
815 |
* not <tt>null</tt> and the invoker's class loader is not the same as or
|
jtulach@119
|
816 |
* an ancestor of the system class loader, then this method invokes the
|
jtulach@119
|
817 |
* security manager's {@link
|
jtulach@119
|
818 |
* SecurityManager#checkPermission(java.security.Permission)
|
jtulach@119
|
819 |
* <tt>checkPermission</tt>} method with a {@link
|
jtulach@119
|
820 |
* RuntimePermission#RuntimePermission(String)
|
jtulach@119
|
821 |
* <tt>RuntimePermission("getClassLoader")</tt>} permission to verify
|
jtulach@119
|
822 |
* access to the system class loader. If not, a
|
jtulach@119
|
823 |
* <tt>SecurityException</tt> will be thrown. </p>
|
jtulach@119
|
824 |
*
|
jtulach@119
|
825 |
* @return The system <tt>ClassLoader</tt> for delegation, or
|
jtulach@119
|
826 |
* <tt>null</tt> if none
|
jtulach@119
|
827 |
*
|
jtulach@119
|
828 |
* @throws SecurityException
|
jtulach@119
|
829 |
* If a security manager exists and its <tt>checkPermission</tt>
|
jtulach@119
|
830 |
* method doesn't allow access to the system class loader.
|
jtulach@119
|
831 |
*
|
jtulach@119
|
832 |
* @throws IllegalStateException
|
jtulach@119
|
833 |
* If invoked recursively during the construction of the class
|
jtulach@119
|
834 |
* loader specified by the "<tt>java.system.class.loader</tt>"
|
jtulach@119
|
835 |
* property.
|
jtulach@119
|
836 |
*
|
jtulach@119
|
837 |
* @throws Error
|
jtulach@119
|
838 |
* If the system property "<tt>java.system.class.loader</tt>"
|
jtulach@119
|
839 |
* is defined but the named class could not be loaded, the
|
jtulach@119
|
840 |
* provider class does not define the required constructor, or an
|
jtulach@119
|
841 |
* exception is thrown by that constructor when it is invoked. The
|
jtulach@119
|
842 |
* underlying cause of the error can be retrieved via the
|
jtulach@119
|
843 |
* {@link Throwable#getCause()} method.
|
jtulach@119
|
844 |
*
|
jtulach@119
|
845 |
* @revised 1.4
|
jtulach@119
|
846 |
*/
|
jtulach@119
|
847 |
public static ClassLoader getSystemClassLoader() {
|
jaroslav@122
|
848 |
throw new SecurityException();
|
jtulach@119
|
849 |
}
|
jtulach@119
|
850 |
|
jtulach@119
|
851 |
// Returns true if the specified class loader can be found in this class
|
jtulach@119
|
852 |
// loader's delegation chain.
|
jtulach@119
|
853 |
boolean isAncestor(ClassLoader cl) {
|
jtulach@119
|
854 |
ClassLoader acl = this;
|
jtulach@119
|
855 |
do {
|
jtulach@119
|
856 |
acl = acl.parent;
|
jtulach@119
|
857 |
if (cl == acl) {
|
jtulach@119
|
858 |
return true;
|
jtulach@119
|
859 |
}
|
jtulach@119
|
860 |
} while (acl != null);
|
jtulach@119
|
861 |
return false;
|
jtulach@119
|
862 |
}
|
jtulach@119
|
863 |
|
jaroslav@122
|
864 |
private boolean checkName(String name) {
|
jaroslav@122
|
865 |
throw new UnsupportedOperationException();
|
jtulach@119
|
866 |
}
|
jtulach@119
|
867 |
|
jaroslav@122
|
868 |
private Class findBootstrapClassOrNull(String name) {
|
jaroslav@122
|
869 |
throw new UnsupportedOperationException();
|
jtulach@119
|
870 |
}
|
jtulach@119
|
871 |
|
jaroslav@122
|
872 |
private static URL getBootstrapResource(String name) {
|
jaroslav@122
|
873 |
throw new UnsupportedOperationException();
|
jaroslav@122
|
874 |
}
|
jaroslav@122
|
875 |
|
jaroslav@122
|
876 |
private static Enumeration<URL> getBootstrapResources(String name) {
|
jaroslav@122
|
877 |
throw new UnsupportedOperationException();
|
jaroslav@122
|
878 |
}
|
jaroslav@122
|
879 |
|
jaroslav@122
|
880 |
private static class CompoundEnumeration implements Enumeration<URL> {
|
jaroslav@122
|
881 |
private URL next;
|
jaroslav@122
|
882 |
private int index;
|
jaroslav@122
|
883 |
private final Enumeration[] arr;
|
jaroslav@122
|
884 |
|
jaroslav@122
|
885 |
public CompoundEnumeration(Enumeration[] arr) {
|
jaroslav@122
|
886 |
this.arr = arr;
|
jaroslav@122
|
887 |
this.index = 0;
|
jtulach@119
|
888 |
}
|
jaroslav@122
|
889 |
|
jaroslav@122
|
890 |
public boolean hasMoreElements() {
|
jaroslav@122
|
891 |
if (next == null) {
|
jaroslav@122
|
892 |
if (arr[index].hasMoreElements()) {
|
jaroslav@122
|
893 |
next = (URL) arr[index].nextElement();
|
jaroslav@122
|
894 |
} else {
|
jaroslav@122
|
895 |
if (index < arr.length) {
|
jaroslav@122
|
896 |
index++;
|
jaroslav@122
|
897 |
return hasMoreElements();
|
jtulach@119
|
898 |
}
|
jtulach@119
|
899 |
}
|
jtulach@119
|
900 |
}
|
jaroslav@122
|
901 |
return next != null;
|
jtulach@119
|
902 |
}
|
jtulach@119
|
903 |
|
jaroslav@122
|
904 |
public URL nextElement() {
|
jaroslav@122
|
905 |
if (!hasMoreElements()) {
|
jaroslav@122
|
906 |
throw new NoSuchElementException();
|
jtulach@119
|
907 |
}
|
jaroslav@122
|
908 |
URL r = next;
|
jaroslav@122
|
909 |
next = null;
|
jaroslav@122
|
910 |
return r;
|
jtulach@119
|
911 |
}
|
jaroslav@122
|
912 |
|
jtulach@119
|
913 |
}
|
jtulach@119
|
914 |
}
|