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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 's': return String.class;
152 case 'o': return Object.class;
153 // case 'V': return Void.TYPE;
155 int up = sig.indexOf("_2");
156 String type = sig.substring(1, up);
157 return Class.forName(type);
158 } catch (ClassNotFoundException ex) {
162 throw new UnsupportedOperationException(sig);
166 * Returns a {@code Type} object that represents the formal return
167 * type of the method represented by this {@code Method} object.
169 * <p>If the return type is a parameterized type,
170 * the {@code Type} object returned must accurately reflect
171 * the actual type parameters used in the source code.
173 * <p>If the return type is a type variable or a parameterized type, it
174 * is created. Otherwise, it is resolved.
176 * @return a {@code Type} object that represents the formal return
177 * type of the underlying method
178 * @throws GenericSignatureFormatError
179 * if the generic method signature does not conform to the format
181 * <cite>The Java™ Virtual Machine Specification</cite>
182 * @throws TypeNotPresentException if the underlying method's
183 * return type refers to a non-existent type declaration
184 * @throws MalformedParameterizedTypeException if the
185 * underlying method's return typed refers to a parameterized
186 * type that cannot be instantiated for any reason
189 public Type getGenericReturnType() {
190 throw new UnsupportedOperationException();
195 * Returns an array of {@code Class} objects that represent the formal
196 * parameter types, in declaration order, of the method
197 * represented by this {@code Method} object. Returns an array of length
198 * 0 if the underlying method takes no parameters.
200 * @return the parameter types for the method this object
203 public Class<?>[] getParameterTypes() {
204 throw new UnsupportedOperationException();
205 //return (Class<?>[]) parameterTypes.clone();
209 * Returns an array of {@code Type} objects that represent the formal
210 * parameter types, in declaration order, of the method represented by
211 * this {@code Method} object. Returns an array of length 0 if the
212 * underlying method takes no parameters.
214 * <p>If a formal parameter type is a parameterized type,
215 * the {@code Type} object returned for it must accurately reflect
216 * the actual type parameters used in the source code.
218 * <p>If a formal parameter type is a type variable or a parameterized
219 * type, it is created. Otherwise, it is resolved.
221 * @return an array of Types that represent the formal
222 * parameter types of the underlying method, in declaration order
223 * @throws GenericSignatureFormatError
224 * if the generic method signature does not conform to the format
226 * <cite>The Java™ Virtual Machine Specification</cite>
227 * @throws TypeNotPresentException if any of the parameter
228 * types of the underlying method refers to a non-existent type
230 * @throws MalformedParameterizedTypeException if any of
231 * the underlying method's parameter types refer to a parameterized
232 * type that cannot be instantiated for any reason
235 public Type[] getGenericParameterTypes() {
236 throw new UnsupportedOperationException();
241 * Returns an array of {@code Class} objects that represent
242 * the types of the exceptions declared to be thrown
243 * by the underlying method
244 * represented by this {@code Method} object. Returns an array of length
245 * 0 if the method declares no exceptions in its {@code throws} clause.
247 * @return the exception types declared as being thrown by the
248 * method this object represents
250 public Class<?>[] getExceptionTypes() {
251 throw new UnsupportedOperationException();
252 //return (Class<?>[]) exceptionTypes.clone();
256 * Returns an array of {@code Type} objects that represent the
257 * exceptions declared to be thrown by this {@code Method} object.
258 * Returns an array of length 0 if the underlying method declares
259 * no exceptions in its {@code throws} clause.
261 * <p>If an exception type is a type variable or a parameterized
262 * type, it is created. Otherwise, it is resolved.
264 * @return an array of Types that represent the exception types
265 * thrown by the underlying method
266 * @throws GenericSignatureFormatError
267 * if the generic method signature does not conform to the format
269 * <cite>The Java™ Virtual Machine Specification</cite>
270 * @throws TypeNotPresentException if the underlying method's
271 * {@code throws} clause refers to a non-existent type declaration
272 * @throws MalformedParameterizedTypeException if
273 * the underlying method's {@code throws} clause refers to a
274 * parameterized type that cannot be instantiated for any reason
277 public Type[] getGenericExceptionTypes() {
278 throw new UnsupportedOperationException();
282 * Compares this {@code Method} against the specified object. Returns
283 * true if the objects are the same. Two {@code Methods} are the same if
284 * they were declared by the same class and have the same name
285 * and formal parameter types and return type.
287 public boolean equals(Object obj) {
288 if (obj != null && obj instanceof Method) {
289 Method other = (Method)obj;
290 return data == other.data;
296 * Returns a hashcode for this {@code Method}. The hashcode is computed
297 * as the exclusive-or of the hashcodes for the underlying
298 * method's declaring class name and the method's name.
300 public int hashCode() {
301 return getDeclaringClass().getName().hashCode() ^ getName().hashCode();
305 * Returns a string describing this {@code Method}. The string is
306 * formatted as the method access modifiers, if any, followed by
307 * the method return type, followed by a space, followed by the
308 * class declaring the method, followed by a period, followed by
309 * the method name, followed by a parenthesized, comma-separated
310 * list of the method's formal parameter types. If the method
311 * throws checked exceptions, the parameter list is followed by a
312 * space, followed by the word throws followed by a
313 * comma-separated list of the thrown exception types.
316 * public boolean java.lang.Object.equals(java.lang.Object)
319 * <p>The access modifiers are placed in canonical order as
320 * specified by "The Java Language Specification". This is
321 * {@code public}, {@code protected} or {@code private} first,
322 * and then other modifiers in the following order:
323 * {@code abstract}, {@code static}, {@code final},
324 * {@code synchronized}, {@code native}, {@code strictfp}.
326 public String toString() {
328 StringBuilder sb = new StringBuilder();
329 int mod = getModifiers() & Modifier.methodModifiers();
331 sb.append(Modifier.toString(mod)).append(' ');
333 sb.append(Field.getTypeName(getReturnType())).append(' ');
334 sb.append(Field.getTypeName(getDeclaringClass())).append('.');
335 sb.append(getName()).append('(');
337 Class<?>[] params = parameterTypes; // avoid clone
338 for (int j = 0; j < params.length; j++) {
339 sb.append(Field.getTypeName(params[j]));
340 if (j < (params.length - 1))
344 Class<?>[] exceptions = exceptionTypes; // avoid clone
345 if (exceptions.length > 0) {
346 sb.append(" throws ");
347 for (int k = 0; k < exceptions.length; k++) {
348 sb.append(exceptions[k].getName());
349 if (k < (exceptions.length - 1))
354 return sb.toString();
355 } catch (Exception e) {
356 return "<" + e + ">";
361 * Returns a string describing this {@code Method}, including
362 * type parameters. The string is formatted as the method access
363 * modifiers, if any, followed by an angle-bracketed
364 * comma-separated list of the method's type parameters, if any,
365 * followed by the method's generic return type, followed by a
366 * space, followed by the class declaring the method, followed by
367 * a period, followed by the method name, followed by a
368 * parenthesized, comma-separated list of the method's generic
369 * formal parameter types.
371 * If this method was declared to take a variable number of
372 * arguments, instead of denoting the last parameter as
373 * "<tt><i>Type</i>[]</tt>", it is denoted as
374 * "<tt><i>Type</i>...</tt>".
376 * A space is used to separate access modifiers from one another
377 * and from the type parameters or return type. If there are no
378 * type parameters, the type parameter list is elided; if the type
379 * parameter list is present, a space separates the list from the
380 * class name. If the method is declared to throw exceptions, the
381 * parameter list is followed by a space, followed by the word
382 * throws followed by a comma-separated list of the generic thrown
383 * exception types. If there are no type parameters, the type
384 * parameter list is elided.
386 * <p>The access modifiers are placed in canonical order as
387 * specified by "The Java Language Specification". This is
388 * {@code public}, {@code protected} or {@code private} first,
389 * and then other modifiers in the following order:
390 * {@code abstract}, {@code static}, {@code final},
391 * {@code synchronized}, {@code native}, {@code strictfp}.
393 * @return a string describing this {@code Method},
394 * include type parameters
398 public String toGenericString() {
400 StringBuilder sb = new StringBuilder();
401 int mod = getModifiers() & Modifier.methodModifiers();
403 sb.append(Modifier.toString(mod)).append(' ');
405 TypeVariable<?>[] typeparms = getTypeParameters();
406 if (typeparms.length > 0) {
407 boolean first = true;
409 for(TypeVariable<?> typeparm: typeparms) {
412 // Class objects can't occur here; no need to test
413 // and call Class.getName().
414 sb.append(typeparm.toString());
420 Type genRetType = getGenericReturnType();
421 sb.append( ((genRetType instanceof Class<?>)?
422 Field.getTypeName((Class<?>)genRetType):genRetType.toString()))
425 sb.append(Field.getTypeName(getDeclaringClass())).append('.');
426 sb.append(getName()).append('(');
427 Type[] params = getGenericParameterTypes();
428 for (int j = 0; j < params.length; j++) {
429 String param = (params[j] instanceof Class)?
430 Field.getTypeName((Class)params[j]):
431 (params[j].toString());
432 if (isVarArgs() && (j == params.length - 1)) // replace T[] with T...
433 param = param.replaceFirst("\\[\\]$", "...");
435 if (j < (params.length - 1))
439 Type[] exceptions = getGenericExceptionTypes();
440 if (exceptions.length > 0) {
441 sb.append(" throws ");
442 for (int k = 0; k < exceptions.length; k++) {
443 sb.append((exceptions[k] instanceof Class)?
444 ((Class)exceptions[k]).getName():
445 exceptions[k].toString());
446 if (k < (exceptions.length - 1))
450 return sb.toString();
451 } catch (Exception e) {
452 return "<" + e + ">";
457 * Invokes the underlying method represented by this {@code Method}
458 * object, on the specified object with the specified parameters.
459 * Individual parameters are automatically unwrapped to match
460 * primitive formal parameters, and both primitive and reference
461 * parameters are subject to method invocation conversions as
464 * <p>If the underlying method is static, then the specified {@code obj}
465 * argument is ignored. It may be null.
467 * <p>If the number of formal parameters required by the underlying method is
468 * 0, the supplied {@code args} array may be of length 0 or null.
470 * <p>If the underlying method is an instance method, it is invoked
471 * using dynamic method lookup as documented in The Java Language
472 * Specification, Second Edition, section 15.12.4.4; in particular,
473 * overriding based on the runtime type of the target object will occur.
475 * <p>If the underlying method is static, the class that declared
476 * the method is initialized if it has not already been initialized.
478 * <p>If the method completes normally, the value it returns is
479 * returned to the caller of invoke; if the value has a primitive
480 * type, it is first appropriately wrapped in an object. However,
481 * if the value has the type of an array of a primitive type, the
482 * elements of the array are <i>not</i> wrapped in objects; in
483 * other words, an array of primitive type is returned. If the
484 * underlying method return type is void, the invocation returns
487 * @param obj the object the underlying method is invoked from
488 * @param args the arguments used for the method call
489 * @return the result of dispatching the method represented by
490 * this object on {@code obj} with parameters
493 * @exception IllegalAccessException if this {@code Method} object
494 * is enforcing Java language access control and the underlying
495 * method is inaccessible.
496 * @exception IllegalArgumentException if the method is an
497 * instance method and the specified object argument
498 * is not an instance of the class or interface
499 * declaring the underlying method (or of a subclass
500 * or implementor thereof); if the number of actual
501 * and formal parameters differ; if an unwrapping
502 * conversion for primitive arguments fails; or if,
503 * after possible unwrapping, a parameter value
504 * cannot be converted to the corresponding formal
505 * parameter type by a method invocation conversion.
506 * @exception InvocationTargetException if the underlying method
507 * throws an exception.
508 * @exception NullPointerException if the specified object is null
509 * and the method is an instance method.
510 * @exception ExceptionInInitializerError if the initialization
511 * provoked by this method fails.
513 public Object invoke(Object obj, Object... args)
514 throws IllegalAccessException, IllegalArgumentException,
515 InvocationTargetException
517 Object res = invoke0(this, obj, args);
518 if (getReturnType().isPrimitive()) {
519 res = fromPrimitive(getReturnType(), res);
524 @JavaScriptBody(args = { "method", "self", "args" }, body =
525 "if (args.length > 0) throw 'unsupported now';"
526 + "return method.fld_data(self);"
528 private static native Object invoke0(Method m, Object self, Object[] args);
530 private static Object fromPrimitive(Class<?> type, Object o) {
531 if (type == Integer.TYPE) {
532 return fromRaw(Integer.class, "valueOf__Ljava_lang_Integer_2I", o);
534 if (type == Long.TYPE) {
535 return fromRaw(Long.class, "valueOf__Ljava_lang_Long_2J", o);
537 if (type == Double.TYPE) {
538 return fromRaw(Double.class, "valueOf__Ljava_lang_Double_2D", o);
540 if (type == Float.TYPE) {
541 return fromRaw(Float.class, "valueOf__Ljava_lang_Float_2F", o);
543 if (type == Byte.TYPE) {
544 return fromRaw(Byte.class, "valueOf__Ljava_lang_Byte_2B", o);
546 if (type == Boolean.TYPE) {
547 return fromRaw(Boolean.class, "valueOf__Ljava_lang_Boolean_2Z", o);
549 if (type == Short.TYPE) {
550 return fromRaw(Short.class, "valueOf__Ljava_lang_Short_2S", o);
552 // case 'V': return Void.TYPE;
553 throw new IllegalStateException("Can't convert " + o);
556 @JavaScriptBody(args = { "cls", "m", "o" },
557 body = "return cls.cnstr(false)[m](o);"
559 private static native Integer fromRaw(Class<?> cls, String m, Object o);
562 * Returns {@code true} if this method is a bridge
563 * method; returns {@code false} otherwise.
565 * @return true if and only if this method is a bridge
566 * method as defined by the Java Language Specification.
569 public boolean isBridge() {
570 return (getModifiers() & Modifier.BRIDGE) != 0;
574 * Returns {@code true} if this method was declared to take
575 * a variable number of arguments; returns {@code false}
578 * @return {@code true} if an only if this method was declared to
579 * take a variable number of arguments.
582 public boolean isVarArgs() {
583 return (getModifiers() & Modifier.VARARGS) != 0;
587 * Returns {@code true} if this method is a synthetic
588 * method; returns {@code false} otherwise.
590 * @return true if and only if this method is a synthetic
591 * method as defined by the Java Language Specification.
594 public boolean isSynthetic() {
595 return Modifier.isSynthetic(getModifiers());
598 @JavaScriptBody(args = { "self", "ac" },
600 "if (self.fld_data.anno) {"
601 + " return self.fld_data.anno['L' + ac.jvmName + ';'];"
602 + "} else return null;"
604 private Object getAnnotationData(Class<?> annotationClass) {
605 throw new UnsupportedOperationException();
609 * @throws NullPointerException {@inheritDoc}
612 public <T extends Annotation> T getAnnotation(Class<T> annotationClass) {
613 Object data = getAnnotationData(annotationClass);
614 return data == null ? null : AnnotationImpl.create(annotationClass, data);
620 public Annotation[] getDeclaredAnnotations() {
621 throw new UnsupportedOperationException();
625 * Returns the default value for the annotation member represented by
626 * this {@code Method} instance. If the member is of a primitive type,
627 * an instance of the corresponding wrapper type is returned. Returns
628 * null if no default is associated with the member, or if the method
629 * instance does not represent a declared member of an annotation type.
631 * @return the default value for the annotation member represented
632 * by this {@code Method} instance.
633 * @throws TypeNotPresentException if the annotation is of type
634 * {@link Class} and no definition can be found for the
635 * default class value.
638 public Object getDefaultValue() {
639 throw new UnsupportedOperationException();
643 * Returns an array of arrays that represent the annotations on the formal
644 * parameters, in declaration order, of the method represented by
645 * this {@code Method} object. (Returns an array of length zero if the
646 * underlying method is parameterless. If the method has one or more
647 * parameters, a nested array of length zero is returned for each parameter
648 * with no annotations.) The annotation objects contained in the returned
649 * arrays are serializable. The caller of this method is free to modify
650 * the returned arrays; it will have no effect on the arrays returned to
653 * @return an array of arrays that represent the annotations on the formal
654 * parameters, in declaration order, of the method represented by this
658 public Annotation[][] getParameterAnnotations() {
659 throw new UnsupportedOperationException();
663 MethodImpl.INSTANCE = new MethodImpl() {
664 protected Method create(Class<?> declaringClass, String name, Object data, String sig) {
665 return new Method(declaringClass, name, data, sig);