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15 * accompanied this code).
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26 package java.lang.reflect;
28 import java.lang.annotation.Annotation;
29 import org.apidesign.bck2brwsr.core.JavaScriptBody;
30 import org.apidesign.bck2brwsr.emul.AnnotationImpl;
31 import org.apidesign.bck2brwsr.emul.MethodImpl;
34 * A {@code Method} provides information about, and access to, a single method
35 * on a class or interface. The reflected method may be a class method
36 * or an instance method (including an abstract method).
38 * <p>A {@code Method} permits widening conversions to occur when matching the
39 * actual parameters to invoke with the underlying method's formal
40 * parameters, but it throws an {@code IllegalArgumentException} if a
41 * narrowing conversion would occur.
44 * @see java.lang.Class
45 * @see java.lang.Class#getMethods()
46 * @see java.lang.Class#getMethod(String, Class[])
47 * @see java.lang.Class#getDeclaredMethods()
48 * @see java.lang.Class#getDeclaredMethod(String, Class[])
50 * @author Kenneth Russell
51 * @author Nakul Saraiya
54 class Method extends AccessibleObject implements GenericDeclaration,
56 private final Class<?> clazz;
57 private final String name;
58 private final Object data;
59 private final String sig;
61 // Generics infrastructure
63 private String getGenericSignature() {return null;}
66 * Package-private constructor used by ReflectAccess to enable
67 * instantiation of these objects in Java code from the java.lang
68 * package via sun.reflect.LangReflectAccess.
70 Method(Class<?> declaringClass, String name, Object data, String sig)
72 this.clazz = declaringClass;
79 * Package-private routine (exposed to java.lang.Class via
80 * ReflectAccess) which returns a copy of this Method. The copy's
81 * "root" field points to this Method.
88 * Returns the {@code Class} object representing the class or interface
89 * that declares the method represented by this {@code Method} object.
91 public Class<?> getDeclaringClass() {
96 * Returns the name of the method represented by this {@code Method}
97 * object, as a {@code String}.
99 public String getName() {
104 * Returns the Java language modifiers for the method represented
105 * by this {@code Method} object, as an integer. The {@code Modifier} class should
106 * be used to decode the modifiers.
110 public int getModifiers() {
111 return getAccess(data);
114 @JavaScriptBody(args = "self", body = "return self.access;")
115 private static native int getAccess(Object self);
118 * Returns an array of {@code TypeVariable} objects that represent the
119 * type variables declared by the generic declaration represented by this
120 * {@code GenericDeclaration} object, in declaration order. Returns an
121 * array of length 0 if the underlying generic declaration declares no type
124 * @return an array of {@code TypeVariable} objects that represent
125 * the type variables declared by this generic declaration
126 * @throws GenericSignatureFormatError if the generic
127 * signature of this generic declaration does not conform to
128 * the format specified in
129 * <cite>The Java™ Virtual Machine Specification</cite>
132 public TypeVariable<Method>[] getTypeParameters() {
133 throw new UnsupportedOperationException();
137 * Returns a {@code Class} object that represents the formal return type
138 * of the method represented by this {@code Method} object.
140 * @return the return type for the method this object represents
142 public Class<?> getReturnType() {
143 switch (sig.charAt(0)) {
144 case 'I': return Integer.TYPE;
145 case 'J': return Long.TYPE;
146 case 'D': return Double.TYPE;
147 case 'F': return Float.TYPE;
148 case 'B': return Byte.TYPE;
149 case 'Z': return Boolean.TYPE;
150 case 'S': return Short.TYPE;
151 // case 'V': return Void.TYPE;
153 int up = sig.indexOf("_2");
154 String type = sig.substring(1, up);
155 return Class.forName(type);
156 } catch (ClassNotFoundException ex) {
160 throw new UnsupportedOperationException(sig);
164 * Returns a {@code Type} object that represents the formal return
165 * type of the method represented by this {@code Method} object.
167 * <p>If the return type is a parameterized type,
168 * the {@code Type} object returned must accurately reflect
169 * the actual type parameters used in the source code.
171 * <p>If the return type is a type variable or a parameterized type, it
172 * is created. Otherwise, it is resolved.
174 * @return a {@code Type} object that represents the formal return
175 * type of the underlying method
176 * @throws GenericSignatureFormatError
177 * if the generic method signature does not conform to the format
179 * <cite>The Java™ Virtual Machine Specification</cite>
180 * @throws TypeNotPresentException if the underlying method's
181 * return type refers to a non-existent type declaration
182 * @throws MalformedParameterizedTypeException if the
183 * underlying method's return typed refers to a parameterized
184 * type that cannot be instantiated for any reason
187 public Type getGenericReturnType() {
188 throw new UnsupportedOperationException();
193 * Returns an array of {@code Class} objects that represent the formal
194 * parameter types, in declaration order, of the method
195 * represented by this {@code Method} object. Returns an array of length
196 * 0 if the underlying method takes no parameters.
198 * @return the parameter types for the method this object
201 public Class<?>[] getParameterTypes() {
202 throw new UnsupportedOperationException();
203 //return (Class<?>[]) parameterTypes.clone();
207 * Returns an array of {@code Type} objects that represent the formal
208 * parameter types, in declaration order, of the method represented by
209 * this {@code Method} object. Returns an array of length 0 if the
210 * underlying method takes no parameters.
212 * <p>If a formal parameter type is a parameterized type,
213 * the {@code Type} object returned for it must accurately reflect
214 * the actual type parameters used in the source code.
216 * <p>If a formal parameter type is a type variable or a parameterized
217 * type, it is created. Otherwise, it is resolved.
219 * @return an array of Types that represent the formal
220 * parameter types of the underlying method, in declaration order
221 * @throws GenericSignatureFormatError
222 * if the generic method signature does not conform to the format
224 * <cite>The Java™ Virtual Machine Specification</cite>
225 * @throws TypeNotPresentException if any of the parameter
226 * types of the underlying method refers to a non-existent type
228 * @throws MalformedParameterizedTypeException if any of
229 * the underlying method's parameter types refer to a parameterized
230 * type that cannot be instantiated for any reason
233 public Type[] getGenericParameterTypes() {
234 throw new UnsupportedOperationException();
239 * Returns an array of {@code Class} objects that represent
240 * the types of the exceptions declared to be thrown
241 * by the underlying method
242 * represented by this {@code Method} object. Returns an array of length
243 * 0 if the method declares no exceptions in its {@code throws} clause.
245 * @return the exception types declared as being thrown by the
246 * method this object represents
248 public Class<?>[] getExceptionTypes() {
249 throw new UnsupportedOperationException();
250 //return (Class<?>[]) exceptionTypes.clone();
254 * Returns an array of {@code Type} objects that represent the
255 * exceptions declared to be thrown by this {@code Method} object.
256 * Returns an array of length 0 if the underlying method declares
257 * no exceptions in its {@code throws} clause.
259 * <p>If an exception type is a type variable or a parameterized
260 * type, it is created. Otherwise, it is resolved.
262 * @return an array of Types that represent the exception types
263 * thrown by the underlying method
264 * @throws GenericSignatureFormatError
265 * if the generic method signature does not conform to the format
267 * <cite>The Java™ Virtual Machine Specification</cite>
268 * @throws TypeNotPresentException if the underlying method's
269 * {@code throws} clause refers to a non-existent type declaration
270 * @throws MalformedParameterizedTypeException if
271 * the underlying method's {@code throws} clause refers to a
272 * parameterized type that cannot be instantiated for any reason
275 public Type[] getGenericExceptionTypes() {
276 throw new UnsupportedOperationException();
280 * Compares this {@code Method} against the specified object. Returns
281 * true if the objects are the same. Two {@code Methods} are the same if
282 * they were declared by the same class and have the same name
283 * and formal parameter types and return type.
285 public boolean equals(Object obj) {
286 if (obj != null && obj instanceof Method) {
287 Method other = (Method)obj;
288 return data == other.data;
294 * Returns a hashcode for this {@code Method}. The hashcode is computed
295 * as the exclusive-or of the hashcodes for the underlying
296 * method's declaring class name and the method's name.
298 public int hashCode() {
299 return getDeclaringClass().getName().hashCode() ^ getName().hashCode();
303 * Returns a string describing this {@code Method}. The string is
304 * formatted as the method access modifiers, if any, followed by
305 * the method return type, followed by a space, followed by the
306 * class declaring the method, followed by a period, followed by
307 * the method name, followed by a parenthesized, comma-separated
308 * list of the method's formal parameter types. If the method
309 * throws checked exceptions, the parameter list is followed by a
310 * space, followed by the word throws followed by a
311 * comma-separated list of the thrown exception types.
314 * public boolean java.lang.Object.equals(java.lang.Object)
317 * <p>The access modifiers are placed in canonical order as
318 * specified by "The Java Language Specification". This is
319 * {@code public}, {@code protected} or {@code private} first,
320 * and then other modifiers in the following order:
321 * {@code abstract}, {@code static}, {@code final},
322 * {@code synchronized}, {@code native}, {@code strictfp}.
324 public String toString() {
326 StringBuilder sb = new StringBuilder();
327 int mod = getModifiers() & Modifier.methodModifiers();
329 sb.append(Modifier.toString(mod)).append(' ');
331 sb.append(Field.getTypeName(getReturnType())).append(' ');
332 sb.append(Field.getTypeName(getDeclaringClass())).append('.');
333 sb.append(getName()).append('(');
335 Class<?>[] params = parameterTypes; // avoid clone
336 for (int j = 0; j < params.length; j++) {
337 sb.append(Field.getTypeName(params[j]));
338 if (j < (params.length - 1))
342 Class<?>[] exceptions = exceptionTypes; // avoid clone
343 if (exceptions.length > 0) {
344 sb.append(" throws ");
345 for (int k = 0; k < exceptions.length; k++) {
346 sb.append(exceptions[k].getName());
347 if (k < (exceptions.length - 1))
352 return sb.toString();
353 } catch (Exception e) {
354 return "<" + e + ">";
359 * Returns a string describing this {@code Method}, including
360 * type parameters. The string is formatted as the method access
361 * modifiers, if any, followed by an angle-bracketed
362 * comma-separated list of the method's type parameters, if any,
363 * followed by the method's generic return type, followed by a
364 * space, followed by the class declaring the method, followed by
365 * a period, followed by the method name, followed by a
366 * parenthesized, comma-separated list of the method's generic
367 * formal parameter types.
369 * If this method was declared to take a variable number of
370 * arguments, instead of denoting the last parameter as
371 * "<tt><i>Type</i>[]</tt>", it is denoted as
372 * "<tt><i>Type</i>...</tt>".
374 * A space is used to separate access modifiers from one another
375 * and from the type parameters or return type. If there are no
376 * type parameters, the type parameter list is elided; if the type
377 * parameter list is present, a space separates the list from the
378 * class name. If the method is declared to throw exceptions, the
379 * parameter list is followed by a space, followed by the word
380 * throws followed by a comma-separated list of the generic thrown
381 * exception types. If there are no type parameters, the type
382 * parameter list is elided.
384 * <p>The access modifiers are placed in canonical order as
385 * specified by "The Java Language Specification". This is
386 * {@code public}, {@code protected} or {@code private} first,
387 * and then other modifiers in the following order:
388 * {@code abstract}, {@code static}, {@code final},
389 * {@code synchronized}, {@code native}, {@code strictfp}.
391 * @return a string describing this {@code Method},
392 * include type parameters
396 public String toGenericString() {
398 StringBuilder sb = new StringBuilder();
399 int mod = getModifiers() & Modifier.methodModifiers();
401 sb.append(Modifier.toString(mod)).append(' ');
403 TypeVariable<?>[] typeparms = getTypeParameters();
404 if (typeparms.length > 0) {
405 boolean first = true;
407 for(TypeVariable<?> typeparm: typeparms) {
410 // Class objects can't occur here; no need to test
411 // and call Class.getName().
412 sb.append(typeparm.toString());
418 Type genRetType = getGenericReturnType();
419 sb.append( ((genRetType instanceof Class<?>)?
420 Field.getTypeName((Class<?>)genRetType):genRetType.toString()))
423 sb.append(Field.getTypeName(getDeclaringClass())).append('.');
424 sb.append(getName()).append('(');
425 Type[] params = getGenericParameterTypes();
426 for (int j = 0; j < params.length; j++) {
427 String param = (params[j] instanceof Class)?
428 Field.getTypeName((Class)params[j]):
429 (params[j].toString());
430 if (isVarArgs() && (j == params.length - 1)) // replace T[] with T...
431 param = param.replaceFirst("\\[\\]$", "...");
433 if (j < (params.length - 1))
437 Type[] exceptions = getGenericExceptionTypes();
438 if (exceptions.length > 0) {
439 sb.append(" throws ");
440 for (int k = 0; k < exceptions.length; k++) {
441 sb.append((exceptions[k] instanceof Class)?
442 ((Class)exceptions[k]).getName():
443 exceptions[k].toString());
444 if (k < (exceptions.length - 1))
448 return sb.toString();
449 } catch (Exception e) {
450 return "<" + e + ">";
455 * Invokes the underlying method represented by this {@code Method}
456 * object, on the specified object with the specified parameters.
457 * Individual parameters are automatically unwrapped to match
458 * primitive formal parameters, and both primitive and reference
459 * parameters are subject to method invocation conversions as
462 * <p>If the underlying method is static, then the specified {@code obj}
463 * argument is ignored. It may be null.
465 * <p>If the number of formal parameters required by the underlying method is
466 * 0, the supplied {@code args} array may be of length 0 or null.
468 * <p>If the underlying method is an instance method, it is invoked
469 * using dynamic method lookup as documented in The Java Language
470 * Specification, Second Edition, section 15.12.4.4; in particular,
471 * overriding based on the runtime type of the target object will occur.
473 * <p>If the underlying method is static, the class that declared
474 * the method is initialized if it has not already been initialized.
476 * <p>If the method completes normally, the value it returns is
477 * returned to the caller of invoke; if the value has a primitive
478 * type, it is first appropriately wrapped in an object. However,
479 * if the value has the type of an array of a primitive type, the
480 * elements of the array are <i>not</i> wrapped in objects; in
481 * other words, an array of primitive type is returned. If the
482 * underlying method return type is void, the invocation returns
485 * @param obj the object the underlying method is invoked from
486 * @param args the arguments used for the method call
487 * @return the result of dispatching the method represented by
488 * this object on {@code obj} with parameters
491 * @exception IllegalAccessException if this {@code Method} object
492 * is enforcing Java language access control and the underlying
493 * method is inaccessible.
494 * @exception IllegalArgumentException if the method is an
495 * instance method and the specified object argument
496 * is not an instance of the class or interface
497 * declaring the underlying method (or of a subclass
498 * or implementor thereof); if the number of actual
499 * and formal parameters differ; if an unwrapping
500 * conversion for primitive arguments fails; or if,
501 * after possible unwrapping, a parameter value
502 * cannot be converted to the corresponding formal
503 * parameter type by a method invocation conversion.
504 * @exception InvocationTargetException if the underlying method
505 * throws an exception.
506 * @exception NullPointerException if the specified object is null
507 * and the method is an instance method.
508 * @exception ExceptionInInitializerError if the initialization
509 * provoked by this method fails.
511 public Object invoke(Object obj, Object... args)
512 throws IllegalAccessException, IllegalArgumentException,
513 InvocationTargetException
515 if ((getModifiers() & Modifier.STATIC) == 0 && obj == null) {
516 throw new NullPointerException();
518 Object res = invoke0(this, obj, args);
519 if (getReturnType().isPrimitive()) {
520 res = fromPrimitive(getReturnType(), res);
525 @JavaScriptBody(args = { "method", "self", "args" }, body =
526 "if (args.length > 0) throw 'unsupported now';"
527 + "return method.fld_data(self);"
529 private static native Object invoke0(Method m, Object self, Object[] args);
531 private static Object fromPrimitive(Class<?> type, Object o) {
532 if (type == Integer.TYPE) {
533 return fromRaw(Integer.class, "valueOf__Ljava_lang_Integer_2I", o);
535 if (type == Long.TYPE) {
536 return fromRaw(Long.class, "valueOf__Ljava_lang_Long_2J", o);
538 if (type == Double.TYPE) {
539 return fromRaw(Double.class, "valueOf__Ljava_lang_Double_2D", o);
541 if (type == Float.TYPE) {
542 return fromRaw(Float.class, "valueOf__Ljava_lang_Float_2F", o);
544 if (type == Byte.TYPE) {
545 return fromRaw(Byte.class, "valueOf__Ljava_lang_Byte_2B", o);
547 if (type == Boolean.TYPE) {
548 return fromRaw(Boolean.class, "valueOf__Ljava_lang_Boolean_2Z", o);
550 if (type == Short.TYPE) {
551 return fromRaw(Short.class, "valueOf__Ljava_lang_Short_2S", o);
553 if (type.getName().equals("void")) {
556 throw new IllegalStateException("Can't convert " + o);
559 @JavaScriptBody(args = { "cls", "m", "o" },
560 body = "return cls.cnstr(false)[m](o);"
562 private static native Integer fromRaw(Class<?> cls, String m, Object o);
565 * Returns {@code true} if this method is a bridge
566 * method; returns {@code false} otherwise.
568 * @return true if and only if this method is a bridge
569 * method as defined by the Java Language Specification.
572 public boolean isBridge() {
573 return (getModifiers() & Modifier.BRIDGE) != 0;
577 * Returns {@code true} if this method was declared to take
578 * a variable number of arguments; returns {@code false}
581 * @return {@code true} if an only if this method was declared to
582 * take a variable number of arguments.
585 public boolean isVarArgs() {
586 return (getModifiers() & Modifier.VARARGS) != 0;
590 * Returns {@code true} if this method is a synthetic
591 * method; returns {@code false} otherwise.
593 * @return true if and only if this method is a synthetic
594 * method as defined by the Java Language Specification.
597 public boolean isSynthetic() {
598 return Modifier.isSynthetic(getModifiers());
601 @JavaScriptBody(args = { "self", "ac" },
603 "if (self.fld_data.anno) {"
604 + " return self.fld_data.anno['L' + ac.jvmName + ';'];"
605 + "} else return null;"
607 private Object getAnnotationData(Class<?> annotationClass) {
608 throw new UnsupportedOperationException();
612 * @throws NullPointerException {@inheritDoc}
615 public <T extends Annotation> T getAnnotation(Class<T> annotationClass) {
616 Object data = getAnnotationData(annotationClass);
617 return data == null ? null : AnnotationImpl.create(annotationClass, data);
623 public Annotation[] getDeclaredAnnotations() {
624 throw new UnsupportedOperationException();
628 * Returns the default value for the annotation member represented by
629 * this {@code Method} instance. If the member is of a primitive type,
630 * an instance of the corresponding wrapper type is returned. Returns
631 * null if no default is associated with the member, or if the method
632 * instance does not represent a declared member of an annotation type.
634 * @return the default value for the annotation member represented
635 * by this {@code Method} instance.
636 * @throws TypeNotPresentException if the annotation is of type
637 * {@link Class} and no definition can be found for the
638 * default class value.
641 public Object getDefaultValue() {
642 throw new UnsupportedOperationException();
646 * Returns an array of arrays that represent the annotations on the formal
647 * parameters, in declaration order, of the method represented by
648 * this {@code Method} object. (Returns an array of length zero if the
649 * underlying method is parameterless. If the method has one or more
650 * parameters, a nested array of length zero is returned for each parameter
651 * with no annotations.) The annotation objects contained in the returned
652 * arrays are serializable. The caller of this method is free to modify
653 * the returned arrays; it will have no effect on the arrays returned to
656 * @return an array of arrays that represent the annotations on the formal
657 * parameters, in declaration order, of the method represented by this
661 public Annotation[][] getParameterAnnotations() {
662 throw new UnsupportedOperationException();
666 MethodImpl.INSTANCE = new MethodImpl() {
667 protected Method create(Class<?> declaringClass, String name, Object data, String sig) {
668 return new Method(declaringClass, name, data, sig);