1 /*
2 * Copyright (c) 2003, 2014, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package sun.reflect.annotation;
27
28 import java.io.ObjectInputStream;
29 import java.lang.annotation.*;
30 import java.lang.reflect.*;
31 import java.io.Serializable;
32 import java.util.*;
33 import java.security.AccessController;
34 import java.security.PrivilegedAction;
35
36 /**
37 * InvocationHandler for dynamic proxy implementation of Annotation.
38 *
39 * @author Josh Bloch
40 * @since 1.5
41 */
42 class AnnotationInvocationHandler implements InvocationHandler, Serializable {
43 private static final long serialVersionUID = 6182022883658399397L;
44 private final Class<? extends Annotation> type;
45 private final Map<String, Object> memberValues;
46
47 AnnotationInvocationHandler(Class<? extends Annotation> type, Map<String, Object> memberValues) {
48 Class<?>[] superInterfaces = type.getInterfaces();
49 if (!type.isAnnotation() ||
50 superInterfaces.length != 1 ||
51 superInterfaces[0] != java.lang.annotation.Annotation.class)
52 throw new AnnotationFormatError("Attempt to create proxy for a non-annotation type.");
53 this.type = type;
54 this.memberValues = memberValues;
55 }
56
57 public Object invoke(Object proxy, Method method, Object[] args) {
58 String member = method.getName();
59 Class<?>[] paramTypes = method.getParameterTypes();
60
61 // Handle Object and Annotation methods
62 if (member.equals("equals") && paramTypes.length == 1 &&
63 paramTypes[0] == Object.class)
64 return equalsImpl(args[0]);
65 if (paramTypes.length != 0)
66 throw new AssertionError("Too many parameters for an annotation method");
67
68 switch(member) {
69 case "toString":
70 return toStringImpl();
71 case "hashCode":
72 return hashCodeImpl();
73 case "annotationType":
74 return type;
75 }
76
77 // Handle annotation member accessors
78 Object result = memberValues.get(member);
79
80 if (result == null)
81 throw new IncompleteAnnotationException(type, member);
82
83 if (result instanceof ExceptionProxy)
84 throw ((ExceptionProxy) result).generateException();
85
86 if (result.getClass().isArray() && Array.getLength(result) != 0)
87 result = cloneArray(result);
88
89 return result;
90 }
91
92 /**
93 * This method, which clones its array argument, would not be necessary
94 * if Cloneable had a public clone method.
95 */
96 private Object cloneArray(Object array) {
97 Class<?> type = array.getClass();
98
99 if (type == byte[].class) {
100 byte[] byteArray = (byte[])array;
101 return byteArray.clone();
102 }
103 if (type == char[].class) {
104 char[] charArray = (char[])array;
105 return charArray.clone();
106 }
107 if (type == double[].class) {
108 double[] doubleArray = (double[])array;
109 return doubleArray.clone();
110 }
111 if (type == float[].class) {
112 float[] floatArray = (float[])array;
113 return floatArray.clone();
114 }
115 if (type == int[].class) {
116 int[] intArray = (int[])array;
117 return intArray.clone();
118 }
119 if (type == long[].class) {
120 long[] longArray = (long[])array;
121 return longArray.clone();
122 }
123 if (type == short[].class) {
124 short[] shortArray = (short[])array;
125 return shortArray.clone();
126 }
127 if (type == boolean[].class) {
128 boolean[] booleanArray = (boolean[])array;
129 return booleanArray.clone();
130 }
131
132 Object[] objectArray = (Object[])array;
133 return objectArray.clone();
134 }
135
136
137 /**
138 * Implementation of dynamicProxy.toString()
139 */
140 private String toStringImpl() {
141 StringBuilder result = new StringBuilder(128);
142 result.append('@');
143 result.append(type.getName());
144 result.append('(');
145 boolean firstMember = true;
146 for (Map.Entry<String, Object> e : memberValues.entrySet()) {
147 if (firstMember)
148 firstMember = false;
149 else
150 result.append(", ");
151
152 result.append(e.getKey());
153 result.append('=');
154 result.append(memberValueToString(e.getValue()));
155 }
156 result.append(')');
157 return result.toString();
158 }
159
160 /**
161 * Translates a member value (in "dynamic proxy return form") into a string
162 */
163 private static String memberValueToString(Object value) {
164 Class<?> type = value.getClass();
165 if (!type.isArray()) // primitive, string, class, enum const,
166 // or annotation
167 return value.toString();
168
169 if (type == byte[].class)
170 return Arrays.toString((byte[]) value);
171 if (type == char[].class)
172 return Arrays.toString((char[]) value);
173 if (type == double[].class)
174 return Arrays.toString((double[]) value);
175 if (type == float[].class)
176 return Arrays.toString((float[]) value);
177 if (type == int[].class)
178 return Arrays.toString((int[]) value);
179 if (type == long[].class)
180 return Arrays.toString((long[]) value);
181 if (type == short[].class)
182 return Arrays.toString((short[]) value);
183 if (type == boolean[].class)
184 return Arrays.toString((boolean[]) value);
185 return Arrays.toString((Object[]) value);
186 }
187
188 /**
189 * Implementation of dynamicProxy.equals(Object o)
190 */
191 private Boolean equalsImpl(Object o) {
192 if (o == this)
193 return true;
194
195 if (!type.isInstance(o))
196 return false;
197 for (Method memberMethod : getMemberMethods()) {
198 String member = memberMethod.getName();
199 Object ourValue = memberValues.get(member);
200 Object hisValue = null;
201 AnnotationInvocationHandler hisHandler = asOneOfUs(o);
202 if (hisHandler != null) {
203 hisValue = hisHandler.memberValues.get(member);
204 } else {
205 try {
206 hisValue = memberMethod.invoke(o);
207 } catch (InvocationTargetException e) {
208 return false;
209 } catch (IllegalAccessException e) {
210 throw new AssertionError(e);
211 }
212 }
213 if (!memberValueEquals(ourValue, hisValue))
214 return false;
215 }
216 return true;
217 }
218
219 /**
220 * Returns an object's invocation handler if that object is a dynamic
221 * proxy with a handler of type AnnotationInvocationHandler.
222 * Returns null otherwise.
223 */
224 private AnnotationInvocationHandler asOneOfUs(Object o) {
225 if (Proxy.isProxyClass(o.getClass())) {
226 InvocationHandler handler = Proxy.getInvocationHandler(o);
227 if (handler instanceof AnnotationInvocationHandler)
228 return (AnnotationInvocationHandler) handler;
229 }
230 return null;
231 }
232
233 /**
234 * Returns true iff the two member values in "dynamic proxy return form"
235 * are equal using the appropriate equality function depending on the
236 * member type. The two values will be of the same type unless one of
237 * the containing annotations is ill-formed. If one of the containing
238 * annotations is ill-formed, this method will return false unless the
239 * two members are identical object references.
240 */
241 private static boolean memberValueEquals(Object v1, Object v2) {
242 Class<?> type = v1.getClass();
243
244 // Check for primitive, string, class, enum const, annotation,
245 // or ExceptionProxy
246 if (!type.isArray())
247 return v1.equals(v2);
248
249 // Check for array of string, class, enum const, annotation,
250 // or ExceptionProxy
251 if (v1 instanceof Object[] && v2 instanceof Object[])
252 return Arrays.equals((Object[]) v1, (Object[]) v2);
253
254 // Check for ill formed annotation(s)
255 if (v2.getClass() != type)
256 return false;
257
258 // Deal with array of primitives
259 if (type == byte[].class)
260 return Arrays.equals((byte[]) v1, (byte[]) v2);
261 if (type == char[].class)
262 return Arrays.equals((char[]) v1, (char[]) v2);
263 if (type == double[].class)
264 return Arrays.equals((double[]) v1, (double[]) v2);
265 if (type == float[].class)
266 return Arrays.equals((float[]) v1, (float[]) v2);
267 if (type == int[].class)
268 return Arrays.equals((int[]) v1, (int[]) v2);
269 if (type == long[].class)
270 return Arrays.equals((long[]) v1, (long[]) v2);
271 if (type == short[].class)
272 return Arrays.equals((short[]) v1, (short[]) v2);
273 assert type == boolean[].class;
274 return Arrays.equals((boolean[]) v1, (boolean[]) v2);
275 }
276
277 /**
278 * Returns the member methods for our annotation type. These are
279 * obtained lazily and cached, as they're expensive to obtain
280 * and we only need them if our equals method is invoked (which should
281 * be rare).
282 */
283 private Method[] getMemberMethods() {
284 Method[] value = memberMethods;
285 if (value == null) {
286 value = computeMemberMethods();
287 memberMethods = value;
288 }
289 return value;
290 }
291
292 private Method[] computeMemberMethods() {
293 return AccessController.doPrivileged(
294 new PrivilegedAction<Method[]>() {
295 public Method[] run() {
296 final Method[] methods = type.getDeclaredMethods();
297 validateAnnotationMethods(methods);
298 AccessibleObject.setAccessible(methods, true);
299 return methods;
300 }});
301 }
302
303 private transient volatile Method[] memberMethods;
304
305 /**
306 * Validates that a method is structurally appropriate for an
307 * annotation type. As of Java SE 8, annotation types cannot
308 * contain static methods and the declared methods of an
309 * annotation type must take zero arguments and there are
310 * restrictions on the return type.
311 */
312 private void validateAnnotationMethods(Method[] memberMethods) {
313 /*
314 * Specification citations below are from JLS
315 * 9.6.1. Annotation Type Elements
316 */
317 boolean valid = true;
318 for(Method method : memberMethods) {
319 /*
320 * "By virtue of the AnnotationTypeElementDeclaration
321 * production, a method declaration in an annotation type
322 * declaration cannot have formal parameters, type
323 * parameters, or a throws clause.
324 *
325 * "By virtue of the AnnotationTypeElementModifier
326 * production, a method declaration in an annotation type
327 * declaration cannot be default or static."
328 */
329 if (method.getModifiers() != (Modifier.PUBLIC | Modifier.ABSTRACT) ||
330 method.isDefault() ||
331 method.getParameterCount() != 0 ||
332 method.getExceptionTypes().length != 0) {
333 valid = false;
334 break;
335 }
336
337 /*
338 * "It is a compile-time error if the return type of a
339 * method declared in an annotation type is not one of the
340 * following: a primitive type, String, Class, any
341 * parameterized invocation of Class, an enum type
342 * (section 8.9), an annotation type, or an array type
343 * (chapter 10) whose element type is one of the preceding
344 * types."
345 */
346 Class<?> returnType = method.getReturnType();
347 if (returnType.isArray()) {
348 returnType = returnType.getComponentType();
349 if (returnType.isArray()) { // Only single dimensional arrays
350 valid = false;
351 break;
352 }
353 }
354
355 if (!((returnType.isPrimitive() && returnType != void.class) ||
356 returnType == java.lang.String.class ||
357 returnType == java.lang.Class.class ||
358 returnType.isEnum() ||
359 returnType.isAnnotation())) {
360 valid = false;
361 break;
362 }
363
364 /*
365 * "It is a compile-time error if any method declared in an
366 * annotation type has a signature that is
367 * override-equivalent to that of any public or protected
368 * method declared in class Object or in the interface
369 * java.lang.annotation.Annotation."
370 *
371 * The methods in Object or Annotation meeting the other
372 * criteria (no arguments, contrained return type, etc.)
373 * above are:
374 *
375 * String toString()
376 * int hashCode()
377 * Class<? extends Annotation> annotationType()
378 */
379 String methodName = method.getName();
380 if ((methodName.equals("toString") && returnType == java.lang.String.class) ||
381 (methodName.equals("hashCode") && returnType == int.class) ||
382 (methodName.equals("annotationType") && returnType == java.lang.Class.class)) {
383 valid = false;
384 break;
385 }
386 }
387 if (valid)
388 return;
389 else
390 throw new AnnotationFormatError("Malformed method on an annotation type");
391 }
392
393 /**
394 * Implementation of dynamicProxy.hashCode()
395 */
396 private int hashCodeImpl() {
397 int result = 0;
398 for (Map.Entry<String, Object> e : memberValues.entrySet()) {
399 result += (127 * e.getKey().hashCode()) ^
400 memberValueHashCode(e.getValue());
401 }
402 return result;
403 }
404
405 /**
406 * Computes hashCode of a member value (in "dynamic proxy return form")
407 */
408 private static int memberValueHashCode(Object value) {
409 Class<?> type = value.getClass();
410 if (!type.isArray()) // primitive, string, class, enum const,
411 // or annotation
412 return value.hashCode();
413
414 if (type == byte[].class)
415 return Arrays.hashCode((byte[]) value);
416 if (type == char[].class)
417 return Arrays.hashCode((char[]) value);
418 if (type == double[].class)
419 return Arrays.hashCode((double[]) value);
420 if (type == float[].class)
421 return Arrays.hashCode((float[]) value);
422 if (type == int[].class)
423 return Arrays.hashCode((int[]) value);
424 if (type == long[].class)
425 return Arrays.hashCode((long[]) value);
426 if (type == short[].class)
427 return Arrays.hashCode((short[]) value);
428 if (type == boolean[].class)
429 return Arrays.hashCode((boolean[]) value);
430 return Arrays.hashCode((Object[]) value);
431 }
432
433 private void readObject(java.io.ObjectInputStream s)
434 throws java.io.IOException, ClassNotFoundException {
435 ObjectInputStream.GetField fields = s.readFields();
436
437 @SuppressWarnings("unchecked")
438 Class<? extends Annotation> t = (Class<? extends Annotation>)fields.get("type", null);
439 @SuppressWarnings("unchecked")
440 Map<String, Object> streamVals = (Map<String, Object>)fields.get("memberValues", null);
441
442 // Check to make sure that types have not evolved incompatibly
443
444 AnnotationType annotationType = null;
445 try {
446 annotationType = AnnotationType.getInstance(t);
447 } catch(IllegalArgumentException e) {
448 // Class is no longer an annotation type; time to punch out
449 throw new java.io.InvalidObjectException("Non-annotation type in annotation serial stream");
450 }
451
452 Map<String, Class<?>> memberTypes = annotationType.memberTypes();
453 // consistent with runtime Map type
454 Map<String, Object> mv = new LinkedHashMap<>();
455
456 // If there are annotation members without values, that
457 // situation is handled by the invoke method.
458 for (Map.Entry<String, Object> memberValue : streamVals.entrySet()) {
459 String name = memberValue.getKey();
460 Object value = null;
461 Class<?> memberType = memberTypes.get(name);
462 if (memberType != null) { // i.e. member still exists
463 value = memberValue.getValue();
464 if (!(memberType.isInstance(value) ||
465 value instanceof ExceptionProxy)) {
466 value = new AnnotationTypeMismatchExceptionProxy(
467 value.getClass() + "[" + value + "]").setMember(
468 annotationType.members().get(name));
469 }
470 }
471 mv.put(name, value);
472 }
473
474 UnsafeAccessor.setType(this, t);
475 UnsafeAccessor.setMemberValues(this, mv);
476 }
477
478 private static class UnsafeAccessor {
479 private static final jdk.internal.misc.Unsafe unsafe;
480 private static final long typeOffset;
481 private static final long memberValuesOffset;
482 static {
483 try {
484 unsafe = jdk.internal.misc.Unsafe.getUnsafe();
485 typeOffset = unsafe.objectFieldOffset
486 (AnnotationInvocationHandler.class.getDeclaredField("type"));
487 memberValuesOffset = unsafe.objectFieldOffset
488 (AnnotationInvocationHandler.class.getDeclaredField("memberValues"));
489 } catch (Exception ex) {
490 throw new ExceptionInInitializerError(ex);
491 }
492 }
493 static void setType(AnnotationInvocationHandler o,
494 Class<? extends Annotation> type) {
495 unsafe.putObject(o, typeOffset, type);
496 }
497
498 static void setMemberValues(AnnotationInvocationHandler o,
499 Map<String, Object> memberValues) {
500 unsafe.putObject(o, memberValuesOffset, memberValues);
501 }
502 }
503 }