-
Notifications
You must be signed in to change notification settings - Fork 21
/
Util.java
790 lines (689 loc) · 25.6 KB
/
Util.java
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
/*
* ---------------
*
* Copied from https://github.com/apache/tomcat/blob/trunk/java/javax/el/Util.java
*
* ---------------
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package javax.el;
import java.lang.ref.WeakReference;
import java.lang.reflect.Array;
import java.lang.reflect.Constructor;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.text.MessageFormat;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Locale;
import java.util.Map;
import java.util.MissingResourceException;
import java.util.ResourceBundle;
import java.util.Set;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReadWriteLock;
import java.util.concurrent.locks.ReentrantReadWriteLock;
class Util {
static String message(ELContext context, String name, Object... props) {
Locale locale = null;
if (context != null) {
locale = context.getLocale();
}
if (locale == null) {
locale = Locale.getDefault();
if (locale == null) {
return "";
}
}
ResourceBundle bundle = ResourceBundle.getBundle(
"javax.el.PrivateMessages", locale);
try {
String template = bundle.getString(name);
if (props != null) {
template = MessageFormat.format(template, props);
}
return template;
} catch (MissingResourceException e) {
return "Missing Resource: '" + name + "' for Locale "
+ locale.getDisplayName();
}
}
private static final CacheValue nullTcclFactory = new CacheValue();
private static final ConcurrentMap<CacheKey, CacheValue> factoryCache =
new ConcurrentHashMap<>();
/**
* Provides a per class loader cache of ExpressionFactory instances without
* pinning any in memory as that could trigger a memory leak.
*/
static ExpressionFactory getExpressionFactory() {
ClassLoader tccl = Thread.currentThread().getContextClassLoader();
CacheValue cacheValue = null;
ExpressionFactory factory = null;
if (tccl == null) {
cacheValue = nullTcclFactory;
} else {
CacheKey key = new CacheKey(tccl);
cacheValue = factoryCache.get(key);
if (cacheValue == null) {
CacheValue newCacheValue = new CacheValue();
cacheValue = factoryCache.putIfAbsent(key, newCacheValue);
if (cacheValue == null) {
cacheValue = newCacheValue;
}
}
}
final Lock readLock = cacheValue.getLock().readLock();
readLock.lock();
try {
factory = cacheValue.getExpressionFactory();
} finally {
readLock.unlock();
}
if (factory == null) {
final Lock writeLock = cacheValue.getLock().writeLock();
writeLock.lock();
try {
factory = cacheValue.getExpressionFactory();
if (factory == null) {
factory = ELUtil.getExpressionFactory();
cacheValue.setExpressionFactory(factory);
}
} finally {
writeLock.unlock();
}
}
return factory;
}
/**
* Key used to cache default ExpressionFactory information per class
* loader. The class loader reference is never {@code null}, because
* {@code null} tccl is handled separately.
*/
private static class CacheKey {
private final int hash;
private final WeakReference<ClassLoader> ref;
public CacheKey(ClassLoader key) {
hash = key.hashCode();
ref = new WeakReference<>(key);
}
@Override
public int hashCode() {
return hash;
}
@Override
public boolean equals(Object obj) {
if (obj == this) {
return true;
}
if (!(obj instanceof CacheKey)) {
return false;
}
ClassLoader thisKey = ref.get();
if (thisKey == null) {
return false;
}
return thisKey == ((CacheKey) obj).ref.get();
}
}
private static class CacheValue {
private final ReadWriteLock lock = new ReentrantReadWriteLock();
private WeakReference<ExpressionFactory> ref;
public CacheValue() {
}
public ReadWriteLock getLock() {
return lock;
}
public ExpressionFactory getExpressionFactory() {
return ref != null ? ref.get() : null;
}
public void setExpressionFactory(ExpressionFactory factory) {
ref = new WeakReference<>(factory);
}
}
/*
* This method duplicates code in org.apache.el.util.ReflectionUtil. When
* making changes keep the code in sync.
*/
static Method findMethod(Class<?> clazz, String methodName,
Class<?>[] paramTypes, Object[] paramValues) {
if (clazz == null || methodName == null) {
throw new MethodNotFoundException(
message(null, "util.method.notfound", clazz, methodName,
paramString(paramTypes)));
}
if (paramTypes == null) {
paramTypes = getTypesFromValues(paramValues);
}
Method[] methods = clazz.getMethods();
List<Wrapper> wrappers = Wrapper.wrap(clazz, methods, methodName);
Wrapper result = findWrapper(
clazz, wrappers, methodName, paramTypes, paramValues);
if (result == null) {
return null;
}
return getMethod(clazz, (Method) result.unWrap());
}
/*
* This method duplicates code in org.apache.el.util.ReflectionUtil. When
* making changes keep the code in sync.
*/
@SuppressWarnings("null")
private static Wrapper findWrapper(Class<?> clazz, List<Wrapper> wrappers,
String name, Class<?>[] paramTypes, Object[] paramValues) {
Map<Wrapper,MatchResult> candidates = new HashMap<>();
int paramCount;
if (paramTypes == null) {
paramCount = 0;
} else {
paramCount = paramTypes.length;
}
for (Wrapper w : wrappers) {
Class<?>[] mParamTypes = w.getParameterTypes();
int mParamCount;
if (mParamTypes == null) {
mParamCount = 0;
} else {
mParamCount = mParamTypes.length;
}
// Check the number of parameters
if (!(paramCount == mParamCount ||
(w.isVarArgs() && paramCount >= mParamCount))) {
// Method has wrong number of parameters
continue;
}
// Check the parameters match
int exactMatch = 0;
int assignableMatch = 0;
int coercibleMatch = 0;
boolean noMatch = false;
for (int i = 0; i < mParamCount; i++) {
// Can't be null
if (mParamTypes[i].equals(paramTypes[i])) {
exactMatch++;
} else if (i == (mParamCount - 1) && w.isVarArgs()) {
Class<?> varType = mParamTypes[i].getComponentType();
for (int j = i; j < paramCount; j++) {
if (isAssignableFrom(paramTypes[j], varType)) {
assignableMatch++;
} else {
if (paramValues == null) {
noMatch = true;
break;
} else {
if (isCoercibleFrom(paramValues[j], varType)) {
coercibleMatch++;
} else {
noMatch = true;
break;
}
}
}
// Don't treat a varArgs match as an exact match, it can
// lead to a varArgs method matching when the result
// should be ambiguous
}
} else if (isAssignableFrom(paramTypes[i], mParamTypes[i])) {
assignableMatch++;
} else {
if (paramValues == null) {
noMatch = true;
break;
} else {
if (isCoercibleFrom(paramValues[i], mParamTypes[i])) {
coercibleMatch++;
} else {
noMatch = true;
break;
}
}
}
}
if (noMatch) {
continue;
}
// If a method is found where every parameter matches exactly,
// return it
if (exactMatch == paramCount) {
return w;
}
candidates.put(w, new MatchResult(
exactMatch, assignableMatch, coercibleMatch, w.isBridge()));
}
// Look for the method that has the highest number of parameters where
// the type matches exactly
MatchResult bestMatch = new MatchResult(0, 0, 0, false);
Wrapper match = null;
boolean multiple = false;
for (Map.Entry<Wrapper, MatchResult> entry : candidates.entrySet()) {
int cmp = entry.getValue().compareTo(bestMatch);
if (cmp > 0 || match == null) {
bestMatch = entry.getValue();
match = entry.getKey();
multiple = false;
} else if (cmp == 0) {
multiple = true;
}
}
if (multiple) {
if (bestMatch.getExact() == paramCount - 1) {
// Only one parameter is not an exact match - try using the
// super class
match = resolveAmbiguousWrapper(candidates.keySet(), paramTypes);
} else {
match = null;
}
if (match == null) {
// If multiple methods have the same matching number of parameters
// the match is ambiguous so throw an exception
throw new MethodNotFoundException(message(
null, "util.method.ambiguous", clazz, name,
paramString(paramTypes)));
}
}
// Handle case where no match at all was found
if (match == null) {
throw new MethodNotFoundException(message(
null, "util.method.notfound", clazz, name,
paramString(paramTypes)));
}
return match;
}
private static final String paramString(Class<?>[] types) {
if (types != null) {
StringBuilder sb = new StringBuilder();
for (int i = 0; i < types.length; i++) {
if (types[i] == null) {
sb.append("null, ");
} else {
sb.append(types[i].getName()).append(", ");
}
}
if (sb.length() > 2) {
sb.setLength(sb.length() - 2);
}
return sb.toString();
}
return null;
}
/*
* This method duplicates code in org.apache.el.util.ReflectionUtil. When
* making changes keep the code in sync.
*/
private static Wrapper resolveAmbiguousWrapper(Set<Wrapper> candidates,
Class<?>[] paramTypes) {
// Identify which parameter isn't an exact match
Wrapper w = candidates.iterator().next();
int nonMatchIndex = 0;
Class<?> nonMatchClass = null;
for (int i = 0; i < paramTypes.length; i++) {
if (w.getParameterTypes()[i] != paramTypes[i]) {
nonMatchIndex = i;
nonMatchClass = paramTypes[i];
break;
}
}
for (Wrapper c : candidates) {
if (c.getParameterTypes()[nonMatchIndex] ==
paramTypes[nonMatchIndex]) {
// Methods have different non-matching parameters
// Result is ambiguous
return null;
}
}
if (nonMatchClass == null) {
// Since null is ambiguous, return the most general method, if possible.
Class<?> mostGeneralType = null;
Wrapper mostGeneralMethod = null;
boolean generalMatchFound = false;
for (Wrapper c : candidates) {
Class<?> candidateType = c.getParameterTypes()[nonMatchIndex];
if (mostGeneralType == null) {
mostGeneralType = candidateType;
mostGeneralMethod = c;
} else if (candidateType.isAssignableFrom(mostGeneralType)) {
mostGeneralType = candidateType;
mostGeneralMethod = c;
generalMatchFound = true;
} else if (mostGeneralType.isAssignableFrom(candidateType)) {
generalMatchFound = true;
}
}
if (generalMatchFound) {
return mostGeneralMethod;
} else {
// Could not determine the most general method
return null;
}
}
// Can't be null
Class<?> superClass = nonMatchClass.getSuperclass();
while (superClass != null) {
for (Wrapper c : candidates) {
if (c.getParameterTypes()[nonMatchIndex].equals(superClass)) {
// Found a match
return c;
}
}
superClass = superClass.getSuperclass();
}
// Treat instances of Number as a special case
Wrapper match = null;
if (Number.class.isAssignableFrom(nonMatchClass)) {
for (Wrapper c : candidates) {
Class<?> candidateType = c.getParameterTypes()[nonMatchIndex];
if (Number.class.isAssignableFrom(candidateType) ||
candidateType.isPrimitive()) {
if (match == null) {
match = c;
} else {
// Match still ambiguous
match = null;
break;
}
}
}
}
return match;
}
/*
* This method duplicates code in org.apache.el.util.ReflectionUtil. When
* making changes keep the code in sync.
*/
static boolean isAssignableFrom(Class<?> src, Class<?> target) {
// src will always be an object
// Short-cut. null is always assignable to an object and in EL null
// can always be coerced to a valid value for a primitive
if (src == null) {
return true;
}
Class<?> targetClass;
if (target.isPrimitive()) {
if (target == Boolean.TYPE) {
targetClass = Boolean.class;
} else if (target == Character.TYPE) {
targetClass = Character.class;
} else if (target == Byte.TYPE) {
targetClass = Byte.class;
} else if (target == Short.TYPE) {
targetClass = Short.class;
} else if (target == Integer.TYPE) {
targetClass = Integer.class;
} else if (target == Long.TYPE) {
targetClass = Long.class;
} else if (target == Float.TYPE) {
targetClass = Float.class;
} else {
targetClass = Double.class;
}
} else {
targetClass = target;
}
return targetClass.isAssignableFrom(src);
}
/*
* This method duplicates code in org.apache.el.util.ReflectionUtil. When
* making changes keep the code in sync.
*/
private static boolean isCoercibleFrom(Object src, Class<?> target) {
// TODO: This isn't pretty but it works. Significant refactoring would
// be required to avoid the exception.
try {
getExpressionFactory().coerceToType(src, target);
} catch (ELException e) {
return false;
}
return true;
}
private static Class<?>[] getTypesFromValues(Object[] values) {
if (values == null) {
return null;
}
Class<?> result[] = new Class<?>[values.length];
for (int i = 0; i < values.length; i++) {
if (values[i] == null) {
result[i] = null;
} else {
result[i] = values[i].getClass();
}
}
return result;
}
/*
* This method duplicates code in org.apache.el.util.ReflectionUtil. When
* making changes keep the code in sync.
*/
static Method getMethod(Class<?> type, Method m) {
if (m == null || Modifier.isPublic(type.getModifiers())) {
return m;
}
Class<?>[] inf = type.getInterfaces();
Method mp = null;
for (int i = 0; i < inf.length; i++) {
try {
mp = inf[i].getMethod(m.getName(), m.getParameterTypes());
mp = getMethod(mp.getDeclaringClass(), mp);
if (mp != null) {
return mp;
}
} catch (NoSuchMethodException e) {
// Ignore
}
}
Class<?> sup = type.getSuperclass();
if (sup != null) {
try {
mp = sup.getMethod(m.getName(), m.getParameterTypes());
mp = getMethod(mp.getDeclaringClass(), mp);
if (mp != null) {
return mp;
}
} catch (NoSuchMethodException e) {
// Ignore
}
}
return null;
}
static Constructor<?> findConstructor(Class<?> clazz, Class<?>[] paramTypes,
Object[] paramValues) {
String methodName = "<init>";
if (clazz == null) {
throw new MethodNotFoundException(
message(null, "util.method.notfound", clazz, methodName,
paramString(paramTypes)));
}
if (paramTypes == null) {
paramTypes = getTypesFromValues(paramValues);
}
Constructor<?>[] constructors = clazz.getConstructors();
List<Wrapper> wrappers = Wrapper.wrap(constructors);
Wrapper result = findWrapper(
clazz, wrappers, methodName, paramTypes, paramValues);
if (result == null) {
return null;
}
return getConstructor(clazz, (Constructor<?>) result.unWrap());
}
static Constructor<?> getConstructor(Class<?> type, Constructor<?> c) {
if (c == null || Modifier.isPublic(type.getModifiers())) {
return c;
}
Constructor<?> cp = null;
Class<?> sup = type.getSuperclass();
if (sup != null) {
try {
cp = sup.getConstructor(c.getParameterTypes());
cp = getConstructor(cp.getDeclaringClass(), cp);
if (cp != null) {
return cp;
}
} catch (NoSuchMethodException e) {
// Ignore
}
}
return null;
}
static Object[] buildParameters(Class<?>[] parameterTypes,
boolean isVarArgs,Object[] params) {
ExpressionFactory factory = getExpressionFactory();
Object[] parameters = null;
if (parameterTypes.length > 0) {
parameters = new Object[parameterTypes.length];
int paramCount = params.length;
if (isVarArgs) {
int varArgIndex = parameterTypes.length - 1;
// First argCount-1 parameters are standard
for (int i = 0; (i < varArgIndex); i++) {
parameters[i] = factory.coerceToType(params[i],
parameterTypes[i]);
}
// Last parameter is the varargs
Class<?> varArgClass =
parameterTypes[varArgIndex].getComponentType();
final Object varargs = Array.newInstance(
varArgClass,
(paramCount - varArgIndex));
for (int i = (varArgIndex); i < paramCount; i++) {
Array.set(varargs, i - varArgIndex,
factory.coerceToType(params[i], varArgClass));
}
parameters[varArgIndex] = varargs;
} else {
parameters = new Object[parameterTypes.length];
for (int i = 0; i < parameterTypes.length; i++) {
parameters[i] = factory.coerceToType(params[i],
parameterTypes[i]);
}
}
}
return parameters;
}
private abstract static class Wrapper {
public static List<Wrapper> wrap(Class<?> clazz, Method[] methods, String name) {
List<Wrapper> result = new ArrayList<>();
for (Method method : methods) {
if (method.getName().equals(name)
&& !(method.isBridge() && !method.getDeclaringClass().equals(clazz))) {
result.add(new MethodWrapper(method));
}
}
return result;
}
public static List<Wrapper> wrap(Constructor<?>[] constructors) {
List<Wrapper> result = new ArrayList<>();
for (Constructor<?> constructor : constructors) {
result.add(new ConstructorWrapper(constructor));
}
return result;
}
public abstract Object unWrap();
public abstract Class<?>[] getParameterTypes();
public abstract boolean isVarArgs();
public abstract boolean isBridge();
}
private static class MethodWrapper extends Wrapper {
private final Method m;
public MethodWrapper(Method m) {
this.m = m;
}
@Override
public Object unWrap() {
return m;
}
@Override
public Class<?>[] getParameterTypes() {
return m.getParameterTypes();
}
@Override
public boolean isVarArgs() {
return m.isVarArgs();
}
@Override
public boolean isBridge() {
return m.isBridge();
}
}
private static class ConstructorWrapper extends Wrapper {
private final Constructor<?> c;
public ConstructorWrapper(Constructor<?> c) {
this.c = c;
}
@Override
public Object unWrap() {
return c;
}
@Override
public Class<?>[] getParameterTypes() {
return c.getParameterTypes();
}
@Override
public boolean isVarArgs() {
return c.isVarArgs();
}
@Override
public boolean isBridge() {
return false;
}
}
/*
* This class duplicates code in org.apache.el.util.ReflectionUtil. When
* making changes keep the code in sync.
*/
private static class MatchResult implements Comparable<MatchResult> {
private final int exact;
private final int assignable;
private final int coercible;
private final boolean bridge;
public MatchResult(int exact, int assignable, int coercible, boolean bridge) {
this.exact = exact;
this.assignable = assignable;
this.coercible = coercible;
this.bridge = bridge;
}
public int getExact() {
return exact;
}
public int getAssignable() {
return assignable;
}
public int getCoercible() {
return coercible;
}
public boolean isBridge() {
return bridge;
}
@Override
public int compareTo(MatchResult o) {
int cmp = Integer.compare(this.getExact(), o.getExact());
if (cmp == 0) {
cmp = Integer.compare(this.getAssignable(), o.getAssignable());
if (cmp == 0) {
cmp = Integer.compare(this.getCoercible(), o.getCoercible());
if (cmp == 0) {
// The nature of bridge methods is such that it actually
// doesn't matter which one we pick as long as we pick
// one. That said, pick the 'right' one (the non-bridge
// one) anyway.
cmp = Boolean.compare(o.isBridge(), this.isBridge());
}
}
}
return cmp;
}
}
}