2 * Copyright (c) 1996, 2006, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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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).
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26 package java.lang.reflect;
28 import java.lang.annotation.Annotation;
29 import java.util.Enumeration;
30 import org.apidesign.bck2brwsr.core.JavaScriptBody;
31 import org.apidesign.bck2brwsr.emul.AnnotationImpl;
32 import org.apidesign.bck2brwsr.emul.MethodImpl;
35 * A {@code Method} provides information about, and access to, a single method
36 * on a class or interface. The reflected method may be a class method
37 * or an instance method (including an abstract method).
39 * <p>A {@code Method} permits widening conversions to occur when matching the
40 * actual parameters to invoke with the underlying method's formal
41 * parameters, but it throws an {@code IllegalArgumentException} if a
42 * narrowing conversion would occur.
45 * @see java.lang.Class
46 * @see java.lang.Class#getMethods()
47 * @see java.lang.Class#getMethod(String, Class[])
48 * @see java.lang.Class#getDeclaredMethods()
49 * @see java.lang.Class#getDeclaredMethod(String, Class[])
51 * @author Kenneth Russell
52 * @author Nakul Saraiya
55 class Method extends AccessibleObject implements GenericDeclaration,
57 private final Class<?> clazz;
58 private final String name;
59 private final Object data;
60 private final String sig;
62 // Generics infrastructure
64 private String getGenericSignature() {return null;}
67 * Package-private constructor used by ReflectAccess to enable
68 * instantiation of these objects in Java code from the java.lang
69 * package via sun.reflect.LangReflectAccess.
71 Method(Class<?> declaringClass, String name, Object data, String sig)
73 this.clazz = declaringClass;
80 * Package-private routine (exposed to java.lang.Class via
81 * ReflectAccess) which returns a copy of this Method. The copy's
82 * "root" field points to this Method.
89 * Returns the {@code Class} object representing the class or interface
90 * that declares the method represented by this {@code Method} object.
92 public Class<?> getDeclaringClass() {
97 * Returns the name of the method represented by this {@code Method}
98 * object, as a {@code String}.
100 public String getName() {
105 * Returns the Java language modifiers for the method represented
106 * by this {@code Method} object, as an integer. The {@code Modifier} class should
107 * be used to decode the modifiers.
111 public int getModifiers() {
112 return getAccess(data);
115 @JavaScriptBody(args = "self", body = "return self.access;")
116 private static native int getAccess(Object self);
119 * Returns an array of {@code TypeVariable} objects that represent the
120 * type variables declared by the generic declaration represented by this
121 * {@code GenericDeclaration} object, in declaration order. Returns an
122 * array of length 0 if the underlying generic declaration declares no type
125 * @return an array of {@code TypeVariable} objects that represent
126 * the type variables declared by this generic declaration
127 * @throws GenericSignatureFormatError if the generic
128 * signature of this generic declaration does not conform to
129 * the format specified in
130 * <cite>The Java™ Virtual Machine Specification</cite>
133 public TypeVariable<Method>[] getTypeParameters() {
134 throw new UnsupportedOperationException();
138 * Returns a {@code Class} object that represents the formal return type
139 * of the method represented by this {@code Method} object.
141 * @return the return type for the method this object represents
143 public Class<?> getReturnType() {
144 return MethodImpl.signatureParser(sig).nextElement();
148 * Returns a {@code Type} object that represents the formal return
149 * type of the method represented by this {@code Method} object.
151 * <p>If the return type is a parameterized type,
152 * the {@code Type} object returned must accurately reflect
153 * the actual type parameters used in the source code.
155 * <p>If the return type is a type variable or a parameterized type, it
156 * is created. Otherwise, it is resolved.
158 * @return a {@code Type} object that represents the formal return
159 * type of the underlying method
160 * @throws GenericSignatureFormatError
161 * if the generic method signature does not conform to the format
163 * <cite>The Java™ Virtual Machine Specification</cite>
164 * @throws TypeNotPresentException if the underlying method's
165 * return type refers to a non-existent type declaration
166 * @throws MalformedParameterizedTypeException if the
167 * underlying method's return typed refers to a parameterized
168 * type that cannot be instantiated for any reason
171 public Type getGenericReturnType() {
172 throw new UnsupportedOperationException();
177 * Returns an array of {@code Class} objects that represent the formal
178 * parameter types, in declaration order, of the method
179 * represented by this {@code Method} object. Returns an array of length
180 * 0 if the underlying method takes no parameters.
182 * @return the parameter types for the method this object
185 public Class<?>[] getParameterTypes() {
186 Class[] arr = new Class[MethodImpl.signatureElements(sig) - 1];
187 Enumeration<Class> en = MethodImpl.signatureParser(sig);
188 en.nextElement(); // return type
189 for (int i = 0; i < arr.length; i++) {
190 arr[i] = en.nextElement();
196 * Returns an array of {@code Type} objects that represent the formal
197 * parameter types, in declaration order, of the method represented by
198 * this {@code Method} object. Returns an array of length 0 if the
199 * underlying method takes no parameters.
201 * <p>If a formal parameter type is a parameterized type,
202 * the {@code Type} object returned for it must accurately reflect
203 * the actual type parameters used in the source code.
205 * <p>If a formal parameter type is a type variable or a parameterized
206 * type, it is created. Otherwise, it is resolved.
208 * @return an array of Types that represent the formal
209 * parameter types of the underlying method, in declaration order
210 * @throws GenericSignatureFormatError
211 * if the generic method signature does not conform to the format
213 * <cite>The Java™ Virtual Machine Specification</cite>
214 * @throws TypeNotPresentException if any of the parameter
215 * types of the underlying method refers to a non-existent type
217 * @throws MalformedParameterizedTypeException if any of
218 * the underlying method's parameter types refer to a parameterized
219 * type that cannot be instantiated for any reason
222 public Type[] getGenericParameterTypes() {
223 throw new UnsupportedOperationException();
228 * Returns an array of {@code Class} objects that represent
229 * the types of the exceptions declared to be thrown
230 * by the underlying method
231 * represented by this {@code Method} object. Returns an array of length
232 * 0 if the method declares no exceptions in its {@code throws} clause.
234 * @return the exception types declared as being thrown by the
235 * method this object represents
237 public Class<?>[] getExceptionTypes() {
238 throw new UnsupportedOperationException();
239 //return (Class<?>[]) exceptionTypes.clone();
243 * Returns an array of {@code Type} objects that represent the
244 * exceptions declared to be thrown by this {@code Method} object.
245 * Returns an array of length 0 if the underlying method declares
246 * no exceptions in its {@code throws} clause.
248 * <p>If an exception type is a type variable or a parameterized
249 * type, it is created. Otherwise, it is resolved.
251 * @return an array of Types that represent the exception types
252 * thrown by the underlying method
253 * @throws GenericSignatureFormatError
254 * if the generic method signature does not conform to the format
256 * <cite>The Java™ Virtual Machine Specification</cite>
257 * @throws TypeNotPresentException if the underlying method's
258 * {@code throws} clause refers to a non-existent type declaration
259 * @throws MalformedParameterizedTypeException if
260 * the underlying method's {@code throws} clause refers to a
261 * parameterized type that cannot be instantiated for any reason
264 public Type[] getGenericExceptionTypes() {
265 throw new UnsupportedOperationException();
269 * Compares this {@code Method} against the specified object. Returns
270 * true if the objects are the same. Two {@code Methods} are the same if
271 * they were declared by the same class and have the same name
272 * and formal parameter types and return type.
274 public boolean equals(Object obj) {
275 if (obj != null && obj instanceof Method) {
276 Method other = (Method)obj;
277 return data == other.data;
283 * Returns a hashcode for this {@code Method}. The hashcode is computed
284 * as the exclusive-or of the hashcodes for the underlying
285 * method's declaring class name and the method's name.
287 public int hashCode() {
288 return getDeclaringClass().getName().hashCode() ^ getName().hashCode();
292 * Returns a string describing this {@code Method}. The string is
293 * formatted as the method access modifiers, if any, followed by
294 * the method return type, followed by a space, followed by the
295 * class declaring the method, followed by a period, followed by
296 * the method name, followed by a parenthesized, comma-separated
297 * list of the method's formal parameter types. If the method
298 * throws checked exceptions, the parameter list is followed by a
299 * space, followed by the word throws followed by a
300 * comma-separated list of the thrown exception types.
303 * public boolean java.lang.Object.equals(java.lang.Object)
306 * <p>The access modifiers are placed in canonical order as
307 * specified by "The Java Language Specification". This is
308 * {@code public}, {@code protected} or {@code private} first,
309 * and then other modifiers in the following order:
310 * {@code abstract}, {@code static}, {@code final},
311 * {@code synchronized}, {@code native}, {@code strictfp}.
313 public String toString() {
315 StringBuilder sb = new StringBuilder();
316 int mod = getModifiers() & Modifier.methodModifiers();
318 sb.append(Modifier.toString(mod)).append(' ');
320 sb.append(Field.getTypeName(getReturnType())).append(' ');
321 sb.append(Field.getTypeName(getDeclaringClass())).append('.');
322 sb.append(getName()).append('(');
323 Class<?>[] params = getParameterTypes(); // avoid clone
324 for (int j = 0; j < params.length; j++) {
325 sb.append(Field.getTypeName(params[j]));
326 if (j < (params.length - 1))
331 Class<?>[] exceptions = exceptionTypes; // avoid clone
332 if (exceptions.length > 0) {
333 sb.append(" throws ");
334 for (int k = 0; k < exceptions.length; k++) {
335 sb.append(exceptions[k].getName());
336 if (k < (exceptions.length - 1))
341 return sb.toString();
342 } catch (Exception e) {
343 return "<" + e + ">";
348 * Returns a string describing this {@code Method}, including
349 * type parameters. The string is formatted as the method access
350 * modifiers, if any, followed by an angle-bracketed
351 * comma-separated list of the method's type parameters, if any,
352 * followed by the method's generic return type, followed by a
353 * space, followed by the class declaring the method, followed by
354 * a period, followed by the method name, followed by a
355 * parenthesized, comma-separated list of the method's generic
356 * formal parameter types.
358 * If this method was declared to take a variable number of
359 * arguments, instead of denoting the last parameter as
360 * "<tt><i>Type</i>[]</tt>", it is denoted as
361 * "<tt><i>Type</i>...</tt>".
363 * A space is used to separate access modifiers from one another
364 * and from the type parameters or return type. If there are no
365 * type parameters, the type parameter list is elided; if the type
366 * parameter list is present, a space separates the list from the
367 * class name. If the method is declared to throw exceptions, the
368 * parameter list is followed by a space, followed by the word
369 * throws followed by a comma-separated list of the generic thrown
370 * exception types. If there are no type parameters, the type
371 * parameter list is elided.
373 * <p>The access modifiers are placed in canonical order as
374 * specified by "The Java Language Specification". This is
375 * {@code public}, {@code protected} or {@code private} first,
376 * and then other modifiers in the following order:
377 * {@code abstract}, {@code static}, {@code final},
378 * {@code synchronized}, {@code native}, {@code strictfp}.
380 * @return a string describing this {@code Method},
381 * include type parameters
385 public String toGenericString() {
387 StringBuilder sb = new StringBuilder();
388 int mod = getModifiers() & Modifier.methodModifiers();
390 sb.append(Modifier.toString(mod)).append(' ');
392 TypeVariable<?>[] typeparms = getTypeParameters();
393 if (typeparms.length > 0) {
394 boolean first = true;
396 for(TypeVariable<?> typeparm: typeparms) {
399 // Class objects can't occur here; no need to test
400 // and call Class.getName().
401 sb.append(typeparm.toString());
407 Type genRetType = getGenericReturnType();
408 sb.append( ((genRetType instanceof Class<?>)?
409 Field.getTypeName((Class<?>)genRetType):genRetType.toString()))
412 sb.append(Field.getTypeName(getDeclaringClass())).append('.');
413 sb.append(getName()).append('(');
414 Type[] params = getGenericParameterTypes();
415 for (int j = 0; j < params.length; j++) {
416 String param = (params[j] instanceof Class)?
417 Field.getTypeName((Class)params[j]):
418 (params[j].toString());
419 if (isVarArgs() && (j == params.length - 1)) // replace T[] with T...
420 param = param.replaceFirst("\\[\\]$", "...");
422 if (j < (params.length - 1))
426 Type[] exceptions = getGenericExceptionTypes();
427 if (exceptions.length > 0) {
428 sb.append(" throws ");
429 for (int k = 0; k < exceptions.length; k++) {
430 sb.append((exceptions[k] instanceof Class)?
431 ((Class)exceptions[k]).getName():
432 exceptions[k].toString());
433 if (k < (exceptions.length - 1))
437 return sb.toString();
438 } catch (Exception e) {
439 return "<" + e + ">";
444 * Invokes the underlying method represented by this {@code Method}
445 * object, on the specified object with the specified parameters.
446 * Individual parameters are automatically unwrapped to match
447 * primitive formal parameters, and both primitive and reference
448 * parameters are subject to method invocation conversions as
451 * <p>If the underlying method is static, then the specified {@code obj}
452 * argument is ignored. It may be null.
454 * <p>If the number of formal parameters required by the underlying method is
455 * 0, the supplied {@code args} array may be of length 0 or null.
457 * <p>If the underlying method is an instance method, it is invoked
458 * using dynamic method lookup as documented in The Java Language
459 * Specification, Second Edition, section 15.12.4.4; in particular,
460 * overriding based on the runtime type of the target object will occur.
462 * <p>If the underlying method is static, the class that declared
463 * the method is initialized if it has not already been initialized.
465 * <p>If the method completes normally, the value it returns is
466 * returned to the caller of invoke; if the value has a primitive
467 * type, it is first appropriately wrapped in an object. However,
468 * if the value has the type of an array of a primitive type, the
469 * elements of the array are <i>not</i> wrapped in objects; in
470 * other words, an array of primitive type is returned. If the
471 * underlying method return type is void, the invocation returns
474 * @param obj the object the underlying method is invoked from
475 * @param args the arguments used for the method call
476 * @return the result of dispatching the method represented by
477 * this object on {@code obj} with parameters
480 * @exception IllegalAccessException if this {@code Method} object
481 * is enforcing Java language access control and the underlying
482 * method is inaccessible.
483 * @exception IllegalArgumentException if the method is an
484 * instance method and the specified object argument
485 * is not an instance of the class or interface
486 * declaring the underlying method (or of a subclass
487 * or implementor thereof); if the number of actual
488 * and formal parameters differ; if an unwrapping
489 * conversion for primitive arguments fails; or if,
490 * after possible unwrapping, a parameter value
491 * cannot be converted to the corresponding formal
492 * parameter type by a method invocation conversion.
493 * @exception InvocationTargetException if the underlying method
494 * throws an exception.
495 * @exception NullPointerException if the specified object is null
496 * and the method is an instance method.
497 * @exception ExceptionInInitializerError if the initialization
498 * provoked by this method fails.
500 public Object invoke(Object obj, Object... args)
501 throws IllegalAccessException, IllegalArgumentException,
502 InvocationTargetException
504 final boolean isStatic = (getModifiers() & Modifier.STATIC) == 0;
505 if (isStatic && obj == null) {
506 throw new NullPointerException();
508 Class[] types = getParameterTypes();
509 if (types.length != args.length) {
510 throw new IllegalArgumentException("Types len " + types.length + " args: " + args.length);
513 for (int i = 0; i < types.length; i++) {
515 if (c.isPrimitive()) {
516 args[i] = toPrimitive(c, args[i]);
520 Object res = invoke0(isStatic, this, obj, args);
521 if (getReturnType().isPrimitive()) {
522 res = fromPrimitive(getReturnType(), res);
527 @JavaScriptBody(args = { "st", "method", "self", "args" }, body =
530 + " p = new Array(1);\n"
532 + " p = p.concat(args);\n"
536 + "return method.fld_data.apply(self, p);\n"
538 private static native Object invoke0(boolean isStatic, Method m, Object self, Object[] args);
540 private static Object fromPrimitive(Class<?> type, Object o) {
541 if (type == Integer.TYPE) {
542 return fromRaw(Integer.class, "valueOf__Ljava_lang_Integer_2I", o);
544 if (type == Long.TYPE) {
545 return fromRaw(Long.class, "valueOf__Ljava_lang_Long_2J", o);
547 if (type == Double.TYPE) {
548 return fromRaw(Double.class, "valueOf__Ljava_lang_Double_2D", o);
550 if (type == Float.TYPE) {
551 return fromRaw(Float.class, "valueOf__Ljava_lang_Float_2F", o);
553 if (type == Byte.TYPE) {
554 return fromRaw(Byte.class, "valueOf__Ljava_lang_Byte_2B", o);
556 if (type == Boolean.TYPE) {
557 return fromRaw(Boolean.class, "valueOf__Ljava_lang_Boolean_2Z", o);
559 if (type == Short.TYPE) {
560 return fromRaw(Short.class, "valueOf__Ljava_lang_Short_2S", o);
562 if (type == Character.TYPE) {
563 return fromRaw(Character.class, "valueOf__Ljava_lang_Character_2C", o);
565 if (type.getName().equals("void")) {
568 throw new IllegalStateException("Can't convert " + o);
571 @JavaScriptBody(args = { "cls", "m", "o" },
572 body = "return cls.cnstr(false)[m](o);"
574 private static native Integer fromRaw(Class<?> cls, String m, Object o);
576 private static Object toPrimitive(Class<?> type, Object o) {
577 if (type == Integer.TYPE) {
578 return toRaw("intValue__I", o);
580 if (type == Long.TYPE) {
581 return toRaw("longValue__J", o);
583 if (type == Double.TYPE) {
584 return toRaw("doubleValue__D", o);
586 if (type == Float.TYPE) {
587 return toRaw("floatValue__F", o);
589 if (type == Byte.TYPE) {
590 return toRaw("byteValue__B", o);
592 if (type == Boolean.TYPE) {
593 return toRaw("booleanValue__Z", o);
595 if (type == Short.TYPE) {
596 return toRaw("shortValue__S", o);
598 if (type == Character.TYPE) {
599 return toRaw("charValue__C", o);
601 if (type.getName().equals("void")) {
604 throw new IllegalStateException("Can't convert " + o);
607 @JavaScriptBody(args = { "m", "o" },
608 body = "return o[m](o);"
610 private static native Object toRaw(String m, Object o);
613 * Returns {@code true} if this method is a bridge
614 * method; returns {@code false} otherwise.
616 * @return true if and only if this method is a bridge
617 * method as defined by the Java Language Specification.
620 public boolean isBridge() {
621 return (getModifiers() & Modifier.BRIDGE) != 0;
625 * Returns {@code true} if this method was declared to take
626 * a variable number of arguments; returns {@code false}
629 * @return {@code true} if an only if this method was declared to
630 * take a variable number of arguments.
633 public boolean isVarArgs() {
634 return (getModifiers() & Modifier.VARARGS) != 0;
638 * Returns {@code true} if this method is a synthetic
639 * method; returns {@code false} otherwise.
641 * @return true if and only if this method is a synthetic
642 * method as defined by the Java Language Specification.
645 public boolean isSynthetic() {
646 return Modifier.isSynthetic(getModifiers());
649 @JavaScriptBody(args = { "ac" },
651 "if (this.fld_data.anno) {"
652 + " return this.fld_data.anno['L' + ac.jvmName + ';'];"
653 + "} else return null;"
655 private Object getAnnotationData(Class<?> annotationClass) {
656 throw new UnsupportedOperationException();
660 * @throws NullPointerException {@inheritDoc}
663 public <T extends Annotation> T getAnnotation(Class<T> annotationClass) {
664 Object data = getAnnotationData(annotationClass);
665 return data == null ? null : AnnotationImpl.create(annotationClass, data);
671 public Annotation[] getDeclaredAnnotations() {
672 throw new UnsupportedOperationException();
676 * Returns the default value for the annotation member represented by
677 * this {@code Method} instance. If the member is of a primitive type,
678 * an instance of the corresponding wrapper type is returned. Returns
679 * null if no default is associated with the member, or if the method
680 * instance does not represent a declared member of an annotation type.
682 * @return the default value for the annotation member represented
683 * by this {@code Method} instance.
684 * @throws TypeNotPresentException if the annotation is of type
685 * {@link Class} and no definition can be found for the
686 * default class value.
689 public Object getDefaultValue() {
690 throw new UnsupportedOperationException();
694 * Returns an array of arrays that represent the annotations on the formal
695 * parameters, in declaration order, of the method represented by
696 * this {@code Method} object. (Returns an array of length zero if the
697 * underlying method is parameterless. If the method has one or more
698 * parameters, a nested array of length zero is returned for each parameter
699 * with no annotations.) The annotation objects contained in the returned
700 * arrays are serializable. The caller of this method is free to modify
701 * the returned arrays; it will have no effect on the arrays returned to
704 * @return an array of arrays that represent the annotations on the formal
705 * parameters, in declaration order, of the method represented by this
709 public Annotation[][] getParameterAnnotations() {
710 throw new UnsupportedOperationException();
714 MethodImpl.INSTANCE = new MethodImpl() {
715 protected Method create(Class<?> declaringClass, String name, Object data, String sig) {
716 return new Method(declaringClass, name, data, sig);