author | chegar |
Thu, 01 Dec 2011 11:09:54 +0000 | |
changeset 11119 | 6ff03c1202ce |
parent 5506 | 202f599c92aa |
child 11124 | 5fdabdc21259 |
permissions | -rw-r--r-- |
2 | 1 |
/* |
5506 | 2 |
* Copyright (c) 2005, 2006, Oracle and/or its affiliates. All rights reserved. |
2 | 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 |
|
5506 | 7 |
* published by the Free Software Foundation. Oracle designates this |
2 | 8 |
* particular file as subject to the "Classpath" exception as provided |
5506 | 9 |
* by Oracle in the LICENSE file that accompanied this code. |
2 | 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 |
* |
|
5506 | 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. |
|
2 | 24 |
*/ |
25 |
||
26 |
package javax.script; |
|
27 |
import java.util.*; |
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28 |
import java.net.URL; |
|
29 |
import java.io.*; |
|
30 |
import java.security.*; |
|
31 |
import sun.misc.Service; |
|
32 |
import sun.misc.ServiceConfigurationError; |
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33 |
import sun.reflect.Reflection; |
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34 |
import sun.security.util.SecurityConstants; |
|
35 |
||
36 |
/** |
|
37 |
* The <code>ScriptEngineManager</code> implements a discovery and instantiation |
|
38 |
* mechanism for <code>ScriptEngine</code> classes and also maintains a |
|
39 |
* collection of key/value pairs storing state shared by all engines created |
|
40 |
* by the Manager. This class uses the <a href="../../../technotes/guides/jar/jar.html#Service%20Provider">service provider</a> mechanism to enumerate all the |
|
41 |
* implementations of <code>ScriptEngineFactory</code>. <br><br> |
|
42 |
* The <code>ScriptEngineManager</code> provides a method to return an array of all these factories |
|
43 |
* as well as utility methods which look up factories on the basis of language name, file extension |
|
44 |
* and mime type. |
|
45 |
* <p> |
|
46 |
* The <code>Bindings</code> of key/value pairs, referred to as the "Global Scope" maintained |
|
47 |
* by the manager is available to all instances of <code>ScriptEngine</code> created |
|
48 |
* by the <code>ScriptEngineManager</code>. The values in the <code>Bindings</code> are |
|
49 |
* generally exposed in all scripts. |
|
50 |
* |
|
51 |
* @author Mike Grogan |
|
52 |
* @author A. Sundararajan |
|
53 |
* @since 1.6 |
|
54 |
*/ |
|
55 |
public class ScriptEngineManager { |
|
56 |
private static final boolean DEBUG = false; |
|
57 |
/** |
|
58 |
* If the thread context ClassLoader can be accessed by the caller, |
|
59 |
* then the effect of calling this constructor is the same as calling |
|
60 |
* <code>ScriptEngineManager(Thread.currentThread().getContextClassLoader())</code>. |
|
61 |
* Otherwise, the effect is the same as calling <code>ScriptEngineManager(null)</code>. |
|
62 |
* |
|
63 |
* @see java.lang.Thread#getContextClassLoader |
|
64 |
*/ |
|
65 |
public ScriptEngineManager() { |
|
66 |
ClassLoader ctxtLoader = Thread.currentThread().getContextClassLoader(); |
|
67 |
if (canCallerAccessLoader(ctxtLoader)) { |
|
68 |
if (DEBUG) System.out.println("using " + ctxtLoader); |
|
69 |
init(ctxtLoader); |
|
70 |
} else { |
|
71 |
if (DEBUG) System.out.println("using bootstrap loader"); |
|
72 |
init(null); |
|
73 |
} |
|
74 |
} |
|
75 |
||
76 |
/** |
|
77 |
* This constructor loads the implementations of |
|
78 |
* <code>ScriptEngineFactory</code> visible to the given |
|
79 |
* <code>ClassLoader</code> using the <a href="../../../technotes/guides/jar/jar.html#Service%20Provider">service provider</a> mechanism.<br><br> |
|
80 |
* If loader is <code>null</code>, the script engine factories that are |
|
81 |
* bundled with the platform and that are in the usual extension |
|
82 |
* directories (installed extensions) are loaded. <br><br> |
|
83 |
* |
|
84 |
* @param loader ClassLoader used to discover script engine factories. |
|
85 |
*/ |
|
86 |
public ScriptEngineManager(ClassLoader loader) { |
|
87 |
init(loader); |
|
88 |
} |
|
89 |
||
90 |
private void init(final ClassLoader loader) { |
|
91 |
globalScope = new SimpleBindings(); |
|
92 |
engineSpis = new HashSet<ScriptEngineFactory>(); |
|
93 |
nameAssociations = new HashMap<String, ScriptEngineFactory>(); |
|
94 |
extensionAssociations = new HashMap<String, ScriptEngineFactory>(); |
|
95 |
mimeTypeAssociations = new HashMap<String, ScriptEngineFactory>(); |
|
96 |
AccessController.doPrivileged(new PrivilegedAction<Object>() { |
|
97 |
public Object run() { |
|
98 |
initEngines(loader); |
|
99 |
return null; |
|
100 |
} |
|
101 |
}); |
|
102 |
} |
|
103 |
||
104 |
private void initEngines(final ClassLoader loader) { |
|
11119
6ff03c1202ce
7116722: Miscellaneous warnings sun.misc ( and related classes )
chegar
parents:
5506
diff
changeset
|
105 |
Iterator<ScriptEngineFactory> itr = null; |
2 | 106 |
try { |
107 |
if (loader != null) { |
|
108 |
itr = Service.providers(ScriptEngineFactory.class, loader); |
|
109 |
} else { |
|
110 |
itr = Service.installedProviders(ScriptEngineFactory.class); |
|
111 |
} |
|
112 |
} catch (ServiceConfigurationError err) { |
|
113 |
System.err.println("Can't find ScriptEngineFactory providers: " + |
|
114 |
err.getMessage()); |
|
115 |
if (DEBUG) { |
|
116 |
err.printStackTrace(); |
|
117 |
} |
|
118 |
// do not throw any exception here. user may want to |
|
119 |
// manage his/her own factories using this manager |
|
120 |
// by explicit registratation (by registerXXX) methods. |
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121 |
return; |
|
122 |
} |
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123 |
||
124 |
try { |
|
125 |
while (itr.hasNext()) { |
|
126 |
try { |
|
11119
6ff03c1202ce
7116722: Miscellaneous warnings sun.misc ( and related classes )
chegar
parents:
5506
diff
changeset
|
127 |
ScriptEngineFactory fact = itr.next(); |
2 | 128 |
engineSpis.add(fact); |
129 |
} catch (ServiceConfigurationError err) { |
|
130 |
System.err.println("ScriptEngineManager providers.next(): " |
|
131 |
+ err.getMessage()); |
|
132 |
if (DEBUG) { |
|
133 |
err.printStackTrace(); |
|
134 |
} |
|
135 |
// one factory failed, but check other factories... |
|
136 |
continue; |
|
137 |
} |
|
138 |
} |
|
139 |
} catch (ServiceConfigurationError err) { |
|
140 |
System.err.println("ScriptEngineManager providers.hasNext(): " |
|
141 |
+ err.getMessage()); |
|
142 |
if (DEBUG) { |
|
143 |
err.printStackTrace(); |
|
144 |
} |
|
145 |
// do not throw any exception here. user may want to |
|
146 |
// manage his/her own factories using this manager |
|
147 |
// by explicit registratation (by registerXXX) methods. |
|
148 |
return; |
|
149 |
} |
|
150 |
} |
|
151 |
||
152 |
/** |
|
153 |
* <code>setBindings</code> stores the specified <code>Bindings</code> |
|
154 |
* in the <code>globalScope</code> field. ScriptEngineManager sets this |
|
155 |
* <code>Bindings</code> as global bindings for <code>ScriptEngine</code> |
|
156 |
* objects created by it. |
|
157 |
* |
|
158 |
* @param bindings The specified <code>Bindings</code> |
|
159 |
* @throws IllegalArgumentException if bindings is null. |
|
160 |
*/ |
|
161 |
public void setBindings(Bindings bindings) { |
|
162 |
if (bindings == null) { |
|
163 |
throw new IllegalArgumentException("Global scope cannot be null."); |
|
164 |
} |
|
165 |
||
166 |
globalScope = bindings; |
|
167 |
} |
|
168 |
||
169 |
/** |
|
170 |
* <code>getBindings</code> returns the value of the <code>globalScope</code> field. |
|
171 |
* ScriptEngineManager sets this <code>Bindings</code> as global bindings for |
|
172 |
* <code>ScriptEngine</code> objects created by it. |
|
173 |
* |
|
174 |
* @return The globalScope field. |
|
175 |
*/ |
|
176 |
public Bindings getBindings() { |
|
177 |
return globalScope; |
|
178 |
} |
|
179 |
||
180 |
/** |
|
181 |
* Sets the specified key/value pair in the Global Scope. |
|
182 |
* @param key Key to set |
|
183 |
* @param value Value to set. |
|
184 |
* @throws NullPointerException if key is null. |
|
185 |
* @throws IllegalArgumentException if key is empty string. |
|
186 |
*/ |
|
187 |
public void put(String key, Object value) { |
|
188 |
globalScope.put(key, value); |
|
189 |
} |
|
190 |
||
191 |
/** |
|
192 |
* Gets the value for the specified key in the Global Scope |
|
193 |
* @param key The key whose value is to be returned. |
|
194 |
* @return The value for the specified key. |
|
195 |
*/ |
|
196 |
public Object get(String key) { |
|
197 |
return globalScope.get(key); |
|
198 |
} |
|
199 |
||
200 |
/** |
|
201 |
* Looks up and creates a <code>ScriptEngine</code> for a given name. |
|
202 |
* The algorithm first searches for a <code>ScriptEngineFactory</code> that has been |
|
203 |
* registered as a handler for the specified name using the <code>registerEngineName</code> |
|
204 |
* method. |
|
205 |
* <br><br> If one is not found, it searches the array of <code>ScriptEngineFactory</code> instances |
|
206 |
* stored by the constructor for one with the specified name. If a <code>ScriptEngineFactory</code> |
|
207 |
* is found by either method, it is used to create instance of <code>ScriptEngine</code>. |
|
208 |
* @param shortName The short name of the <code>ScriptEngine</code> implementation. |
|
209 |
* returned by the <code>getNames</code> method of its <code>ScriptEngineFactory</code>. |
|
210 |
* @return A <code>ScriptEngine</code> created by the factory located in the search. Returns null |
|
211 |
* if no such factory was found. The <code>ScriptEngineManager</code> sets its own <code>globalScope</code> |
|
212 |
* <code>Bindings</code> as the <code>GLOBAL_SCOPE</code> <code>Bindings</code> of the newly |
|
213 |
* created <code>ScriptEngine</code>. |
|
214 |
* @throws NullPointerException if shortName is null. |
|
215 |
*/ |
|
216 |
public ScriptEngine getEngineByName(String shortName) { |
|
217 |
if (shortName == null) throw new NullPointerException(); |
|
218 |
//look for registered name first |
|
219 |
Object obj; |
|
220 |
if (null != (obj = nameAssociations.get(shortName))) { |
|
221 |
ScriptEngineFactory spi = (ScriptEngineFactory)obj; |
|
222 |
try { |
|
223 |
ScriptEngine engine = spi.getScriptEngine(); |
|
224 |
engine.setBindings(getBindings(), ScriptContext.GLOBAL_SCOPE); |
|
225 |
return engine; |
|
226 |
} catch (Exception exp) { |
|
227 |
if (DEBUG) exp.printStackTrace(); |
|
228 |
} |
|
229 |
} |
|
230 |
||
231 |
for (ScriptEngineFactory spi : engineSpis) { |
|
232 |
List<String> names = null; |
|
233 |
try { |
|
234 |
names = spi.getNames(); |
|
235 |
} catch (Exception exp) { |
|
236 |
if (DEBUG) exp.printStackTrace(); |
|
237 |
} |
|
238 |
||
239 |
if (names != null) { |
|
240 |
for (String name : names) { |
|
241 |
if (shortName.equals(name)) { |
|
242 |
try { |
|
243 |
ScriptEngine engine = spi.getScriptEngine(); |
|
244 |
engine.setBindings(getBindings(), ScriptContext.GLOBAL_SCOPE); |
|
245 |
return engine; |
|
246 |
} catch (Exception exp) { |
|
247 |
if (DEBUG) exp.printStackTrace(); |
|
248 |
} |
|
249 |
} |
|
250 |
} |
|
251 |
} |
|
252 |
} |
|
253 |
||
254 |
return null; |
|
255 |
} |
|
256 |
||
257 |
/** |
|
258 |
* Look up and create a <code>ScriptEngine</code> for a given extension. The algorithm |
|
259 |
* used by <code>getEngineByName</code> is used except that the search starts |
|
260 |
* by looking for a <code>ScriptEngineFactory</code> registered to handle the |
|
261 |
* given extension using <code>registerEngineExtension</code>. |
|
262 |
* @param extension The given extension |
|
263 |
* @return The engine to handle scripts with this extension. Returns <code>null</code> |
|
264 |
* if not found. |
|
265 |
* @throws NullPointerException if extension is null. |
|
266 |
*/ |
|
267 |
public ScriptEngine getEngineByExtension(String extension) { |
|
268 |
if (extension == null) throw new NullPointerException(); |
|
269 |
//look for registered extension first |
|
270 |
Object obj; |
|
271 |
if (null != (obj = extensionAssociations.get(extension))) { |
|
272 |
ScriptEngineFactory spi = (ScriptEngineFactory)obj; |
|
273 |
try { |
|
274 |
ScriptEngine engine = spi.getScriptEngine(); |
|
275 |
engine.setBindings(getBindings(), ScriptContext.GLOBAL_SCOPE); |
|
276 |
return engine; |
|
277 |
} catch (Exception exp) { |
|
278 |
if (DEBUG) exp.printStackTrace(); |
|
279 |
} |
|
280 |
} |
|
281 |
||
282 |
for (ScriptEngineFactory spi : engineSpis) { |
|
283 |
List<String> exts = null; |
|
284 |
try { |
|
285 |
exts = spi.getExtensions(); |
|
286 |
} catch (Exception exp) { |
|
287 |
if (DEBUG) exp.printStackTrace(); |
|
288 |
} |
|
289 |
if (exts == null) continue; |
|
290 |
for (String ext : exts) { |
|
291 |
if (extension.equals(ext)) { |
|
292 |
try { |
|
293 |
ScriptEngine engine = spi.getScriptEngine(); |
|
294 |
engine.setBindings(getBindings(), ScriptContext.GLOBAL_SCOPE); |
|
295 |
return engine; |
|
296 |
} catch (Exception exp) { |
|
297 |
if (DEBUG) exp.printStackTrace(); |
|
298 |
} |
|
299 |
} |
|
300 |
} |
|
301 |
} |
|
302 |
return null; |
|
303 |
} |
|
304 |
||
305 |
/** |
|
306 |
* Look up and create a <code>ScriptEngine</code> for a given mime type. The algorithm |
|
307 |
* used by <code>getEngineByName</code> is used except that the search starts |
|
308 |
* by looking for a <code>ScriptEngineFactory</code> registered to handle the |
|
309 |
* given mime type using <code>registerEngineMimeType</code>. |
|
310 |
* @param mimeType The given mime type |
|
311 |
* @return The engine to handle scripts with this mime type. Returns <code>null</code> |
|
312 |
* if not found. |
|
313 |
* @throws NullPointerException if mimeType is null. |
|
314 |
*/ |
|
315 |
public ScriptEngine getEngineByMimeType(String mimeType) { |
|
316 |
if (mimeType == null) throw new NullPointerException(); |
|
317 |
//look for registered types first |
|
318 |
Object obj; |
|
319 |
if (null != (obj = mimeTypeAssociations.get(mimeType))) { |
|
320 |
ScriptEngineFactory spi = (ScriptEngineFactory)obj; |
|
321 |
try { |
|
322 |
ScriptEngine engine = spi.getScriptEngine(); |
|
323 |
engine.setBindings(getBindings(), ScriptContext.GLOBAL_SCOPE); |
|
324 |
return engine; |
|
325 |
} catch (Exception exp) { |
|
326 |
if (DEBUG) exp.printStackTrace(); |
|
327 |
} |
|
328 |
} |
|
329 |
||
330 |
for (ScriptEngineFactory spi : engineSpis) { |
|
331 |
List<String> types = null; |
|
332 |
try { |
|
333 |
types = spi.getMimeTypes(); |
|
334 |
} catch (Exception exp) { |
|
335 |
if (DEBUG) exp.printStackTrace(); |
|
336 |
} |
|
337 |
if (types == null) continue; |
|
338 |
for (String type : types) { |
|
339 |
if (mimeType.equals(type)) { |
|
340 |
try { |
|
341 |
ScriptEngine engine = spi.getScriptEngine(); |
|
342 |
engine.setBindings(getBindings(), ScriptContext.GLOBAL_SCOPE); |
|
343 |
return engine; |
|
344 |
} catch (Exception exp) { |
|
345 |
if (DEBUG) exp.printStackTrace(); |
|
346 |
} |
|
347 |
} |
|
348 |
} |
|
349 |
} |
|
350 |
return null; |
|
351 |
} |
|
352 |
||
353 |
/** |
|
354 |
* Returns an array whose elements are instances of all the <code>ScriptEngineFactory</code> classes |
|
355 |
* found by the discovery mechanism. |
|
356 |
* @return List of all discovered <code>ScriptEngineFactory</code>s. |
|
357 |
*/ |
|
358 |
public List<ScriptEngineFactory> getEngineFactories() { |
|
359 |
List<ScriptEngineFactory> res = new ArrayList<ScriptEngineFactory>(engineSpis.size()); |
|
360 |
for (ScriptEngineFactory spi : engineSpis) { |
|
361 |
res.add(spi); |
|
362 |
} |
|
363 |
return Collections.unmodifiableList(res); |
|
364 |
} |
|
365 |
||
366 |
/** |
|
367 |
* Registers a <code>ScriptEngineFactory</code> to handle a language |
|
368 |
* name. Overrides any such association found using the Discovery mechanism. |
|
369 |
* @param name The name to be associated with the <code>ScriptEngineFactory</code>. |
|
370 |
* @param factory The class to associate with the given name. |
|
371 |
* @throws NullPointerException if any of the parameters is null. |
|
372 |
*/ |
|
373 |
public void registerEngineName(String name, ScriptEngineFactory factory) { |
|
374 |
if (name == null || factory == null) throw new NullPointerException(); |
|
375 |
nameAssociations.put(name, factory); |
|
376 |
} |
|
377 |
||
378 |
/** |
|
379 |
* Registers a <code>ScriptEngineFactory</code> to handle a mime type. |
|
380 |
* Overrides any such association found using the Discovery mechanism. |
|
381 |
* |
|
382 |
* @param type The mime type to be associated with the |
|
383 |
* <code>ScriptEngineFactory</code>. |
|
384 |
* |
|
385 |
* @param factory The class to associate with the given mime type. |
|
386 |
* @throws NullPointerException if any of the parameters is null. |
|
387 |
*/ |
|
388 |
public void registerEngineMimeType(String type, ScriptEngineFactory factory) { |
|
389 |
if (type == null || factory == null) throw new NullPointerException(); |
|
390 |
mimeTypeAssociations.put(type, factory); |
|
391 |
} |
|
392 |
||
393 |
/** |
|
394 |
* Registers a <code>ScriptEngineFactory</code> to handle an extension. |
|
395 |
* Overrides any such association found using the Discovery mechanism. |
|
396 |
* |
|
397 |
* @param extension The extension type to be associated with the |
|
398 |
* <code>ScriptEngineFactory</code>. |
|
399 |
* @param factory The class to associate with the given extension. |
|
400 |
* @throws NullPointerException if any of the parameters is null. |
|
401 |
*/ |
|
402 |
public void registerEngineExtension(String extension, ScriptEngineFactory factory) { |
|
403 |
if (extension == null || factory == null) throw new NullPointerException(); |
|
404 |
extensionAssociations.put(extension, factory); |
|
405 |
} |
|
406 |
||
407 |
/** Set of script engine factories discovered. */ |
|
408 |
private HashSet<ScriptEngineFactory> engineSpis; |
|
409 |
||
410 |
/** Map of engine name to script engine factory. */ |
|
411 |
private HashMap<String, ScriptEngineFactory> nameAssociations; |
|
412 |
||
413 |
/** Map of script file extension to script engine factory. */ |
|
414 |
private HashMap<String, ScriptEngineFactory> extensionAssociations; |
|
415 |
||
416 |
/** Map of script script MIME type to script engine factory. */ |
|
417 |
private HashMap<String, ScriptEngineFactory> mimeTypeAssociations; |
|
418 |
||
419 |
/** Global bindings associated with script engines created by this manager. */ |
|
420 |
private Bindings globalScope; |
|
421 |
||
422 |
private boolean canCallerAccessLoader(ClassLoader loader) { |
|
423 |
SecurityManager sm = System.getSecurityManager(); |
|
424 |
if (sm != null) { |
|
425 |
ClassLoader callerLoader = getCallerClassLoader(); |
|
426 |
if (callerLoader != null) { |
|
427 |
if (loader != callerLoader || !isAncestor(loader, callerLoader)) { |
|
428 |
try { |
|
429 |
sm.checkPermission(SecurityConstants.GET_CLASSLOADER_PERMISSION); |
|
430 |
} catch (SecurityException exp) { |
|
431 |
if (DEBUG) exp.printStackTrace(); |
|
432 |
return false; |
|
433 |
} |
|
434 |
} // else fallthru.. |
|
435 |
} // else fallthru.. |
|
436 |
} // else fallthru.. |
|
437 |
||
438 |
return true; |
|
439 |
} |
|
440 |
||
441 |
// Note that this code is same as ClassLoader.getCallerClassLoader(). |
|
442 |
// But, that method is package private and hence we can't call here. |
|
443 |
private ClassLoader getCallerClassLoader() { |
|
11119
6ff03c1202ce
7116722: Miscellaneous warnings sun.misc ( and related classes )
chegar
parents:
5506
diff
changeset
|
444 |
Class<?> caller = Reflection.getCallerClass(3); |
2 | 445 |
if (caller == null) { |
446 |
return null; |
|
447 |
} |
|
448 |
return caller.getClassLoader(); |
|
449 |
} |
|
450 |
||
451 |
// is cl1 ancestor of cl2? |
|
452 |
private boolean isAncestor(ClassLoader cl1, ClassLoader cl2) { |
|
453 |
do { |
|
454 |
cl2 = cl2.getParent(); |
|
455 |
if (cl1 == cl2) return true; |
|
456 |
} while (cl2 != null); |
|
457 |
return false; |
|
458 |
} |
|
459 |
} |