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* Copyright (c) 1996, 2006, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
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*
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package java.lang.reflect;
import sun.reflect.CallerSensitive;
import sun.reflect.MethodAccessor;
import sun.reflect.Reflection;
import sun.reflect.generics.repository.MethodRepository;
import sun.reflect.generics.factory.CoreReflectionFactory;
import sun.reflect.generics.factory.GenericsFactory;
import sun.reflect.generics.scope.MethodScope;
import sun.reflect.annotation.AnnotationType;
import sun.reflect.annotation.AnnotationParser;
import java.lang.annotation.Annotation;
import java.lang.annotation.AnnotationFormatError;
import java.nio.ByteBuffer;
import java.util.Map;
A Method
provides information about, and access to, a single method on a class or interface. The reflected method may be a class method or an instance method (including an abstract method). A Method
permits widening conversions to occur when matching the actual parameters to invoke with the underlying method's formal parameters, but it throws an IllegalArgumentException
if a narrowing conversion would occur.
Author: Kenneth Russell, Nakul Saraiya See Also:
/**
* A {@code Method} provides information about, and access to, a single method
* on a class or interface. The reflected method may be a class method
* or an instance method (including an abstract method).
*
* <p>A {@code Method} permits widening conversions to occur when matching the
* actual parameters to invoke with the underlying method's formal
* parameters, but it throws an {@code IllegalArgumentException} if a
* narrowing conversion would occur.
*
* @see Member
* @see java.lang.Class
* @see java.lang.Class#getMethods()
* @see java.lang.Class#getMethod(String, Class[])
* @see java.lang.Class#getDeclaredMethods()
* @see java.lang.Class#getDeclaredMethod(String, Class[])
*
* @author Kenneth Russell
* @author Nakul Saraiya
*/
public final
class Method extends AccessibleObject implements GenericDeclaration,
Member {
private Class<?> clazz;
private int slot;
// This is guaranteed to be interned by the VM in the 1.4
// reflection implementation
private String name;
private Class<?> returnType;
private Class<?>[] parameterTypes;
private Class<?>[] exceptionTypes;
private int modifiers;
// Generics and annotations support
private transient String signature;
// generic info repository; lazily initialized
private transient MethodRepository genericInfo;
private byte[] annotations;
private byte[] parameterAnnotations;
private byte[] annotationDefault;
private volatile MethodAccessor methodAccessor;
// For sharing of MethodAccessors. This branching structure is
// currently only two levels deep (i.e., one root Method and
// potentially many Method objects pointing to it.)
private Method root;
// More complicated security check cache needed here than for
// Class.newInstance() and Constructor.newInstance()
private Class securityCheckCache;
private Class securityCheckTargetClassCache;
// Modifiers that can be applied to a method in source code
private static final int LANGUAGE_MODIFIERS =
Modifier.PUBLIC | Modifier.PROTECTED | Modifier.PRIVATE |
Modifier.ABSTRACT | Modifier.STATIC | Modifier.FINAL |
Modifier.SYNCHRONIZED | Modifier.NATIVE;
// Generics infrastructure
private String getGenericSignature() {return signature;}
// Accessor for factory
private GenericsFactory getFactory() {
// create scope and factory
return CoreReflectionFactory.make(this, MethodScope.make(this));
}
// Accessor for generic info repository
private MethodRepository getGenericInfo() {
// lazily initialize repository if necessary
if (genericInfo == null) {
// create and cache generic info repository
genericInfo = MethodRepository.make(getGenericSignature(),
getFactory());
}
return genericInfo; //return cached repository
}
Package-private constructor used by ReflectAccess to enable
instantiation of these objects in Java code from the java.lang
package via sun.reflect.LangReflectAccess.
/**
* Package-private constructor used by ReflectAccess to enable
* instantiation of these objects in Java code from the java.lang
* package via sun.reflect.LangReflectAccess.
*/
Method(Class<?> declaringClass,
String name,
Class<?>[] parameterTypes,
Class<?> returnType,
Class<?>[] checkedExceptions,
int modifiers,
int slot,
String signature,
byte[] annotations,
byte[] parameterAnnotations,
byte[] annotationDefault)
{
this.clazz = declaringClass;
this.name = name;
this.parameterTypes = parameterTypes;
this.returnType = returnType;
this.exceptionTypes = checkedExceptions;
this.modifiers = modifiers;
this.slot = slot;
this.signature = signature;
this.annotations = annotations;
this.parameterAnnotations = parameterAnnotations;
this.annotationDefault = annotationDefault;
}
Package-private routine (exposed to java.lang.Class via
ReflectAccess) which returns a copy of this Method. The copy's
"root" field points to this Method.
/**
* Package-private routine (exposed to java.lang.Class via
* ReflectAccess) which returns a copy of this Method. The copy's
* "root" field points to this Method.
*/
Method copy() {
// This routine enables sharing of MethodAccessor objects
// among Method objects which refer to the same underlying
// method in the VM. (All of this contortion is only necessary
// because of the "accessibility" bit in AccessibleObject,
// which implicitly requires that new java.lang.reflect
// objects be fabricated for each reflective call on Class
// objects.)
Method res = new Method(clazz, name, parameterTypes, returnType,
exceptionTypes, modifiers, slot, signature,
annotations, parameterAnnotations, annotationDefault);
res.root = this;
// Might as well eagerly propagate this if already present
res.methodAccessor = methodAccessor;
return res;
}
Returns the Class
object representing the class or interface that declares the method represented by this Method
object. /**
* Returns the {@code Class} object representing the class or interface
* that declares the method represented by this {@code Method} object.
*/
public Class<?> getDeclaringClass() {
return clazz;
}
Returns the name of the method represented by this Method
object, as a String
. /**
* Returns the name of the method represented by this {@code Method}
* object, as a {@code String}.
*/
public String getName() {
return name;
}
Returns the Java language modifiers for the method represented by this Method
object, as an integer. The Modifier
class should be used to decode the modifiers. See Also:
/**
* Returns the Java language modifiers for the method represented
* by this {@code Method} object, as an integer. The {@code Modifier} class should
* be used to decode the modifiers.
*
* @see Modifier
*/
public int getModifiers() {
return modifiers;
}
Returns an array of TypeVariable
objects that represent the type variables declared by the generic declaration represented by this GenericDeclaration
object, in declaration order. Returns an array of length 0 if the underlying generic declaration declares no type variables. Throws: - GenericSignatureFormatError – if the generic
signature of this generic declaration does not conform to
the format specified in the Java Virtual Machine Specification,
3rd edition
Returns: an array of TypeVariable
objects that represent the type variables declared by this generic declaration Since: 1.5
/**
* Returns an array of {@code TypeVariable} objects that represent the
* type variables declared by the generic declaration represented by this
* {@code GenericDeclaration} object, in declaration order. Returns an
* array of length 0 if the underlying generic declaration declares no type
* variables.
*
* @return an array of {@code TypeVariable} objects that represent
* the type variables declared by this generic declaration
* @throws GenericSignatureFormatError if the generic
* signature of this generic declaration does not conform to
* the format specified in the Java Virtual Machine Specification,
* 3rd edition
* @since 1.5
*/
public TypeVariable<Method>[] getTypeParameters() {
if (getGenericSignature() != null)
return (TypeVariable<Method>[])getGenericInfo().getTypeParameters();
else
return (TypeVariable<Method>[])new TypeVariable[0];
}
Returns a Class
object that represents the formal return type of the method represented by this Method
object. Returns: the return type for the method this object represents
/**
* Returns a {@code Class} object that represents the formal return type
* of the method represented by this {@code Method} object.
*
* @return the return type for the method this object represents
*/
public Class<?> getReturnType() {
return returnType;
}
Returns a Type
object that represents the formal return type of the method represented by this Method
object. If the return type is a parameterized type, the Type
object returned must accurately reflect the actual type parameters used in the source code.
If the return type is a type variable or a parameterized type, it
is created. Otherwise, it is resolved.
Throws: - GenericSignatureFormatError –
if the generic method signature does not conform to the format
specified in the Java Virtual Machine Specification, 3rd edition
- TypeNotPresentException – if the underlying method's
return type refers to a non-existent type declaration
- MalformedParameterizedTypeException – if the
underlying method's return typed refers to a parameterized
type that cannot be instantiated for any reason
Returns: a Type
object that represents the formal return type of the underlying method Since: 1.5
/**
* Returns a {@code Type} object that represents the formal return
* type of the method represented by this {@code Method} object.
*
* <p>If the return type is a parameterized type,
* the {@code Type} object returned must accurately reflect
* the actual type parameters used in the source code.
*
* <p>If the return type is a type variable or a parameterized type, it
* is created. Otherwise, it is resolved.
*
* @return a {@code Type} object that represents the formal return
* type of the underlying method
* @throws GenericSignatureFormatError
* if the generic method signature does not conform to the format
* specified in the Java Virtual Machine Specification, 3rd edition
* @throws TypeNotPresentException if the underlying method's
* return type refers to a non-existent type declaration
* @throws MalformedParameterizedTypeException if the
* underlying method's return typed refers to a parameterized
* type that cannot be instantiated for any reason
* @since 1.5
*/
public Type getGenericReturnType() {
if (getGenericSignature() != null) {
return getGenericInfo().getReturnType();
} else { return getReturnType();}
}
Returns an array of Class
objects that represent the formal parameter types, in declaration order, of the method represented by this Method
object. Returns an array of length 0 if the underlying method takes no parameters. Returns: the parameter types for the method this object
represents
/**
* Returns an array of {@code Class} objects that represent the formal
* parameter types, in declaration order, of the method
* represented by this {@code Method} object. Returns an array of length
* 0 if the underlying method takes no parameters.
*
* @return the parameter types for the method this object
* represents
*/
public Class<?>[] getParameterTypes() {
return (Class<?>[]) parameterTypes.clone();
}
Returns an array of Type
objects that represent the formal parameter types, in declaration order, of the method represented by this Method
object. Returns an array of length 0 if the underlying method takes no parameters. If a formal parameter type is a parameterized type, the Type
object returned for it must accurately reflect the actual type parameters used in the source code.
If a formal parameter type is a type variable or a parameterized
type, it is created. Otherwise, it is resolved.
Throws: - GenericSignatureFormatError –
if the generic method signature does not conform to the format
specified in the Java Virtual Machine Specification, 3rd edition
- TypeNotPresentException – if any of the parameter
types of the underlying method refers to a non-existent type
declaration
- MalformedParameterizedTypeException – if any of
the underlying method's parameter types refer to a parameterized
type that cannot be instantiated for any reason
Returns: an array of Types that represent the formal
parameter types of the underlying method, in declaration order Since: 1.5
/**
* Returns an array of {@code Type} objects that represent the formal
* parameter types, in declaration order, of the method represented by
* this {@code Method} object. Returns an array of length 0 if the
* underlying method takes no parameters.
*
* <p>If a formal parameter type is a parameterized type,
* the {@code Type} object returned for it must accurately reflect
* the actual type parameters used in the source code.
*
* <p>If a formal parameter type is a type variable or a parameterized
* type, it is created. Otherwise, it is resolved.
*
* @return an array of Types that represent the formal
* parameter types of the underlying method, in declaration order
* @throws GenericSignatureFormatError
* if the generic method signature does not conform to the format
* specified in the Java Virtual Machine Specification, 3rd edition
* @throws TypeNotPresentException if any of the parameter
* types of the underlying method refers to a non-existent type
* declaration
* @throws MalformedParameterizedTypeException if any of
* the underlying method's parameter types refer to a parameterized
* type that cannot be instantiated for any reason
* @since 1.5
*/
public Type[] getGenericParameterTypes() {
if (getGenericSignature() != null)
return getGenericInfo().getParameterTypes();
else
return getParameterTypes();
}
Returns an array of Class
objects that represent the types of the exceptions declared to be thrown by the underlying method represented by this Method
object. Returns an array of length 0 if the method declares no exceptions in its throws
clause. Returns: the exception types declared as being thrown by the
method this object represents
/**
* Returns an array of {@code Class} objects that represent
* the types of the exceptions declared to be thrown
* by the underlying method
* represented by this {@code Method} object. Returns an array of length
* 0 if the method declares no exceptions in its {@code throws} clause.
*
* @return the exception types declared as being thrown by the
* method this object represents
*/
public Class<?>[] getExceptionTypes() {
return (Class<?>[]) exceptionTypes.clone();
}
Returns an array of Type
objects that represent the exceptions declared to be thrown by this Method
object. Returns an array of length 0 if the underlying method declares no exceptions in its throws
clause. If an exception type is a parameterized type, the Type
object returned for it must accurately reflect the actual type parameters used in the source code.
If an exception type is a type variable or a parameterized
type, it is created. Otherwise, it is resolved.
Throws: - GenericSignatureFormatError –
if the generic method signature does not conform to the format
specified in the Java Virtual Machine Specification, 3rd edition
- TypeNotPresentException – if the underlying method's
throws
clause refers to a non-existent type declaration - MalformedParameterizedTypeException – if the underlying method's
throws
clause refers to a parameterized type that cannot be instantiated for any reason
Returns: an array of Types that represent the exception types
thrown by the underlying method Since: 1.5
/**
* Returns an array of {@code Type} objects that represent the
* exceptions declared to be thrown by this {@code Method} object.
* Returns an array of length 0 if the underlying method declares
* no exceptions in its {@code throws} clause.
*
* <p>If an exception type is a parameterized type, the {@code Type}
* object returned for it must accurately reflect the actual type
* parameters used in the source code.
*
* <p>If an exception type is a type variable or a parameterized
* type, it is created. Otherwise, it is resolved.
*
* @return an array of Types that represent the exception types
* thrown by the underlying method
* @throws GenericSignatureFormatError
* if the generic method signature does not conform to the format
* specified in the Java Virtual Machine Specification, 3rd edition
* @throws TypeNotPresentException if the underlying method's
* {@code throws} clause refers to a non-existent type declaration
* @throws MalformedParameterizedTypeException if
* the underlying method's {@code throws} clause refers to a
* parameterized type that cannot be instantiated for any reason
* @since 1.5
*/
public Type[] getGenericExceptionTypes() {
Type[] result;
if (getGenericSignature() != null &&
((result = getGenericInfo().getExceptionTypes()).length > 0))
return result;
else
return getExceptionTypes();
}
Compares this Method
against the specified object. Returns true if the objects are the same. Two Methods
are the same if they were declared by the same class and have the same name and formal parameter types and return type. /**
* Compares this {@code Method} against the specified object. Returns
* true if the objects are the same. Two {@code Methods} are the same if
* they were declared by the same class and have the same name
* and formal parameter types and return type.
*/
public boolean equals(Object obj) {
if (obj != null && obj instanceof Method) {
Method other = (Method)obj;
if ((getDeclaringClass() == other.getDeclaringClass())
&& (getName() == other.getName())) {
if (!returnType.equals(other.getReturnType()))
return false;
/* Avoid unnecessary cloning */
Class<?>[] params1 = parameterTypes;
Class<?>[] params2 = other.parameterTypes;
if (params1.length == params2.length) {
for (int i = 0; i < params1.length; i++) {
if (params1[i] != params2[i])
return false;
}
return true;
}
}
}
return false;
}
Returns a hashcode for this Method
. The hashcode is computed as the exclusive-or of the hashcodes for the underlying method's declaring class name and the method's name. /**
* Returns a hashcode for this {@code Method}. The hashcode is computed
* as the exclusive-or of the hashcodes for the underlying
* method's declaring class name and the method's name.
*/
public int hashCode() {
return getDeclaringClass().getName().hashCode() ^ getName().hashCode();
}
Returns a string describing this Method
. The string is formatted as the method access modifiers, if any, followed by the method return type, followed by a space, followed by the class declaring the method, followed by a period, followed by the method name, followed by a parenthesized, comma-separated list of the method's formal parameter types. If the method throws checked exceptions, the parameter list is followed by a space, followed by the word throws followed by a comma-separated list of the thrown exception types. For example: public boolean java.lang.Object.equals(java.lang.Object)
The access modifiers are placed in canonical order as specified by "The Java Language Specification". This is public
, protected
or private
first, and then other modifiers in the following order: abstract
, static
, final
, synchronized
, native
.
/**
* Returns a string describing this {@code Method}. The string is
* formatted as the method access modifiers, if any, followed by
* the method return type, followed by a space, followed by the
* class declaring the method, followed by a period, followed by
* the method name, followed by a parenthesized, comma-separated
* list of the method's formal parameter types. If the method
* throws checked exceptions, the parameter list is followed by a
* space, followed by the word throws followed by a
* comma-separated list of the thrown exception types.
* For example:
* <pre>
* public boolean java.lang.Object.equals(java.lang.Object)
* </pre>
*
* <p>The access modifiers are placed in canonical order as
* specified by "The Java Language Specification". This is
* {@code public}, {@code protected} or {@code private} first,
* and then other modifiers in the following order:
* {@code abstract}, {@code static}, {@code final},
* {@code synchronized}, {@code native}.
*/
public String toString() {
try {
StringBuffer sb = new StringBuffer();
int mod = getModifiers() & LANGUAGE_MODIFIERS;
if (mod != 0) {
sb.append(Modifier.toString(mod) + " ");
}
sb.append(Field.getTypeName(getReturnType()) + " ");
sb.append(Field.getTypeName(getDeclaringClass()) + ".");
sb.append(getName() + "(");
Class[] params = parameterTypes; // avoid clone
for (int j = 0; j < params.length; j++) {
sb.append(Field.getTypeName(params[j]));
if (j < (params.length - 1))
sb.append(",");
}
sb.append(")");
Class<?>[] exceptions = exceptionTypes; // avoid clone
if (exceptions.length > 0) {
sb.append(" throws ");
for (int k = 0; k < exceptions.length; k++) {
sb.append(exceptions[k].getName());
if (k < (exceptions.length - 1))
sb.append(",");
}
}
return sb.toString();
} catch (Exception e) {
return "<" + e + ">";
}
}
Returns a string describing this Method
, including type parameters. The string is formatted as the method access modifiers, if any, followed by an angle-bracketed comma-separated list of the method's type parameters, if any, followed by the method's generic return type, followed by a space, followed by the class declaring the method, followed by a period, followed by the method name, followed by a parenthesized, comma-separated list of the method's generic formal parameter types. A space is used to separate access modifiers from one another and from the type parameters or return type. If there are no type parameters, the type parameter list is elided; if the type parameter list is present, a space separates the list from the class name. If the method is declared to throw exceptions, the parameter list is followed by a space, followed by the word throws followed by a comma-separated list of the generic thrown exception types. If there are no type parameters, the type parameter list is elided. The access modifiers are placed in canonical order as specified by "The Java Language Specification". This is public
, protected
or private
first, and then other modifiers in the following order: abstract
, static
, final
, synchronized
native
.
Returns: a string describing this Method
, include type parameters Since: 1.5
/**
* Returns a string describing this {@code Method}, including
* type parameters. The string is formatted as the method access
* modifiers, if any, followed by an angle-bracketed
* comma-separated list of the method's type parameters, if any,
* followed by the method's generic return type, followed by a
* space, followed by the class declaring the method, followed by
* a period, followed by the method name, followed by a
* parenthesized, comma-separated list of the method's generic
* formal parameter types.
*
* A space is used to separate access modifiers from one another
* and from the type parameters or return type. If there are no
* type parameters, the type parameter list is elided; if the type
* parameter list is present, a space separates the list from the
* class name. If the method is declared to throw exceptions, the
* parameter list is followed by a space, followed by the word
* throws followed by a comma-separated list of the generic thrown
* exception types. If there are no type parameters, the type
* parameter list is elided.
*
* <p>The access modifiers are placed in canonical order as
* specified by "The Java Language Specification". This is
* {@code public}, {@code protected} or {@code private} first,
* and then other modifiers in the following order:
* {@code abstract}, {@code static}, {@code final},
* {@code synchronized} {@code native}.
*
* @return a string describing this {@code Method},
* include type parameters
*
* @since 1.5
*/
public String toGenericString() {
try {
StringBuilder sb = new StringBuilder();
int mod = getModifiers() & LANGUAGE_MODIFIERS;
if (mod != 0) {
sb.append(Modifier.toString(mod) + " ");
}
TypeVariable<?>[] typeparms = getTypeParameters();
if (typeparms.length > 0) {
boolean first = true;
sb.append("<");
for(TypeVariable<?> typeparm: typeparms) {
if (!first)
sb.append(",");
// Class objects can't occur here; no need to test
// and call Class.getName().
sb.append(typeparm.toString());
first = false;
}
sb.append("> ");
}
Type genRetType = getGenericReturnType();
sb.append( ((genRetType instanceof Class<?>)?
Field.getTypeName((Class<?>)genRetType):genRetType.toString()) + " ");
sb.append(Field.getTypeName(getDeclaringClass()) + ".");
sb.append(getName() + "(");
Type[] params = getGenericParameterTypes();
for (int j = 0; j < params.length; j++) {
String param = (params[j] instanceof Class)?
Field.getTypeName((Class)params[j]):
(params[j].toString());
sb.append(param);
if (j < (params.length - 1))
sb.append(",");
}
sb.append(")");
Type[] exceptions = getGenericExceptionTypes();
if (exceptions.length > 0) {
sb.append(" throws ");
for (int k = 0; k < exceptions.length; k++) {
sb.append((exceptions[k] instanceof Class)?
((Class)exceptions[k]).getName():
exceptions[k].toString());
if (k < (exceptions.length - 1))
sb.append(",");
}
}
return sb.toString();
} catch (Exception e) {
return "<" + e + ">";
}
}
Invokes the underlying method represented by this Method
object, on the specified object with the specified parameters. Individual parameters are automatically unwrapped to match primitive formal parameters, and both primitive and reference parameters are subject to method invocation conversions as necessary. If the underlying method is static, then the specified obj
argument is ignored. It may be null.
If the number of formal parameters required by the underlying method is 0, the supplied args
array may be of length 0 or null.
If the underlying method is an instance method, it is invoked
using dynamic method lookup as documented in The Java Language
Specification, Second Edition, section 15.12.4.4; in particular,
overriding based on the runtime type of the target object will occur.
If the underlying method is static, the class that declared
the method is initialized if it has not already been initialized.
If the method completes normally, the value it returns is
returned to the caller of invoke; if the value has a primitive
type, it is first appropriately wrapped in an object. However,
if the value has the type of an array of a primitive type, the
elements of the array are not wrapped in objects; in
other words, an array of primitive type is returned. If the
underlying method return type is void, the invocation returns
null.
Params: - obj – the object the underlying method is invoked from
- args – the arguments used for the method call
Throws: - IllegalAccessException – if this
Method
object enforces Java language access control and the underlying method is inaccessible. - IllegalArgumentException – if the method is an
instance method and the specified object argument
is not an instance of the class or interface
declaring the underlying method (or of a subclass
or implementor thereof); if the number of actual
and formal parameters differ; if an unwrapping
conversion for primitive arguments fails; or if,
after possible unwrapping, a parameter value
cannot be converted to the corresponding formal
parameter type by a method invocation conversion.
- InvocationTargetException – if the underlying method
throws an exception.
- NullPointerException – if the specified object is null
and the method is an instance method.
- ExceptionInInitializerError – if the initialization
provoked by this method fails.
Returns: the result of dispatching the method represented by this object on obj
with parameters args
/**
* Invokes the underlying method represented by this {@code Method}
* object, on the specified object with the specified parameters.
* Individual parameters are automatically unwrapped to match
* primitive formal parameters, and both primitive and reference
* parameters are subject to method invocation conversions as
* necessary.
*
* <p>If the underlying method is static, then the specified {@code obj}
* argument is ignored. It may be null.
*
* <p>If the number of formal parameters required by the underlying method is
* 0, the supplied {@code args} array may be of length 0 or null.
*
* <p>If the underlying method is an instance method, it is invoked
* using dynamic method lookup as documented in The Java Language
* Specification, Second Edition, section 15.12.4.4; in particular,
* overriding based on the runtime type of the target object will occur.
*
* <p>If the underlying method is static, the class that declared
* the method is initialized if it has not already been initialized.
*
* <p>If the method completes normally, the value it returns is
* returned to the caller of invoke; if the value has a primitive
* type, it is first appropriately wrapped in an object. However,
* if the value has the type of an array of a primitive type, the
* elements of the array are <i>not</i> wrapped in objects; in
* other words, an array of primitive type is returned. If the
* underlying method return type is void, the invocation returns
* null.
*
* @param obj the object the underlying method is invoked from
* @param args the arguments used for the method call
* @return the result of dispatching the method represented by
* this object on {@code obj} with parameters
* {@code args}
*
* @exception IllegalAccessException if this {@code Method} object
* enforces Java language access control and the underlying
* method is inaccessible.
* @exception IllegalArgumentException if the method is an
* instance method and the specified object argument
* is not an instance of the class or interface
* declaring the underlying method (or of a subclass
* or implementor thereof); if the number of actual
* and formal parameters differ; if an unwrapping
* conversion for primitive arguments fails; or if,
* after possible unwrapping, a parameter value
* cannot be converted to the corresponding formal
* parameter type by a method invocation conversion.
* @exception InvocationTargetException if the underlying method
* throws an exception.
* @exception NullPointerException if the specified object is null
* and the method is an instance method.
* @exception ExceptionInInitializerError if the initialization
* provoked by this method fails.
*/
@CallerSensitive
public Object invoke(Object obj, Object... args)
throws IllegalAccessException, IllegalArgumentException,
InvocationTargetException
{
if (!override) {
if (!Reflection.quickCheckMemberAccess(clazz, modifiers)) {
// Until there is hotspot @CallerSensitive support
// can't call Reflection.getCallerClass() here
// Workaround for now: add a frame getCallerClass to
// make the caller at stack depth 2
Class<?> caller = getCallerClass();
Class targetClass = ((obj == null || !Modifier.isProtected(modifiers))
? clazz
: obj.getClass());
boolean cached;
synchronized (this) {
cached = (securityCheckCache == caller)
&& (securityCheckTargetClassCache == targetClass);
}
if (!cached) {
Reflection.ensureMemberAccess(caller, clazz, obj, modifiers);
synchronized (this) {
securityCheckCache = caller;
securityCheckTargetClassCache = targetClass;
}
}
}
}
if (methodAccessor == null) acquireMethodAccessor();
return methodAccessor.invoke(obj, args);
}
/*
* This method makes the frame count to be 2 to find the caller
*/
@CallerSensitive
private Class<?> getCallerClass() {
// Reflection.getCallerClass() currently returns the frame at depth 2
// before the hotspot support is in.
return Reflection.getCallerClass();
}
Returns true
if this method is a bridge method; returns false
otherwise. Returns: true if and only if this method is a bridge
method as defined by the Java Language Specification. Since: 1.5
/**
* Returns {@code true} if this method is a bridge
* method; returns {@code false} otherwise.
*
* @return true if and only if this method is a bridge
* method as defined by the Java Language Specification.
* @since 1.5
*/
public boolean isBridge() {
return (getModifiers() & Modifier.BRIDGE) != 0;
}
Returns true
if this method was declared to take a variable number of arguments; returns false
otherwise. Returns: true
if an only if this method was declared to take a variable number of arguments.Since: 1.5
/**
* Returns {@code true} if this method was declared to take
* a variable number of arguments; returns {@code false}
* otherwise.
*
* @return {@code true} if an only if this method was declared to
* take a variable number of arguments.
* @since 1.5
*/
public boolean isVarArgs() {
return (getModifiers() & Modifier.VARARGS) != 0;
}
Returns true
if this method is a synthetic method; returns false
otherwise. Returns: true if and only if this method is a synthetic
method as defined by the Java Language Specification. Since: 1.5
/**
* Returns {@code true} if this method is a synthetic
* method; returns {@code false} otherwise.
*
* @return true if and only if this method is a synthetic
* method as defined by the Java Language Specification.
* @since 1.5
*/
public boolean isSynthetic() {
return Modifier.isSynthetic(getModifiers());
}
// NOTE that there is no synchronization used here. It is correct
// (though not efficient) to generate more than one MethodAccessor
// for a given Method. However, avoiding synchronization will
// probably make the implementation more scalable.
private void acquireMethodAccessor() {
// First check to see if one has been created yet, and take it
// if so
MethodAccessor tmp = null;
if (root != null) tmp = root.getMethodAccessor();
if (tmp != null) {
methodAccessor = tmp;
return;
}
// Otherwise fabricate one and propagate it up to the root
tmp = reflectionFactory.newMethodAccessor(this);
setMethodAccessor(tmp);
}
// Returns MethodAccessor for this Method object, not looking up
// the chain to the root
MethodAccessor getMethodAccessor() {
return methodAccessor;
}
// Sets the MethodAccessor for this Method object and
// (recursively) its root
void setMethodAccessor(MethodAccessor accessor) {
methodAccessor = accessor;
// Propagate up
if (root != null) {
root.setMethodAccessor(accessor);
}
}
Throws: - NullPointerException – {@inheritDoc}
Since: 1.5
/**
* @throws NullPointerException {@inheritDoc}
* @since 1.5
*/
public <T extends Annotation> T getAnnotation(Class<T> annotationClass) {
if (annotationClass == null)
throw new NullPointerException();
return (T) declaredAnnotations().get(annotationClass);
}
private static final Annotation[] EMPTY_ANNOTATION_ARRAY=new Annotation[0];
Since: 1.5
/**
* @since 1.5
*/
public Annotation[] getDeclaredAnnotations() {
return declaredAnnotations().values().toArray(EMPTY_ANNOTATION_ARRAY);
}
private transient Map<Class<? extends Annotation>, Annotation> declaredAnnotations;
private synchronized Map<Class<? extends Annotation>, Annotation> declaredAnnotations() {
if (declaredAnnotations == null) {
declaredAnnotations = AnnotationParser.parseAnnotations(
annotations, sun.misc.SharedSecrets.getJavaLangAccess().
getConstantPool(getDeclaringClass()),
getDeclaringClass());
}
return declaredAnnotations;
}
Returns the default value for the annotation member represented by this Method
instance. If the member is of a primitive type, an instance of the corresponding wrapper type is returned. Returns null if no default is associated with the member, or if the method instance does not represent a declared member of an annotation type. Throws: - TypeNotPresentException – if the annotation is of type
Class
and no definition can be found for the default class value.
Returns: the default value for the annotation member represented by this Method
instance. Since: 1.5
/**
* Returns the default value for the annotation member represented by
* this {@code Method} instance. If the member is of a primitive type,
* an instance of the corresponding wrapper type is returned. Returns
* null if no default is associated with the member, or if the method
* instance does not represent a declared member of an annotation type.
*
* @return the default value for the annotation member represented
* by this {@code Method} instance.
* @throws TypeNotPresentException if the annotation is of type
* {@link Class} and no definition can be found for the
* default class value.
* @since 1.5
*/
public Object getDefaultValue() {
if (annotationDefault == null)
return null;
Class<?> memberType = AnnotationType.invocationHandlerReturnType(
getReturnType());
Object result = AnnotationParser.parseMemberValue(
memberType, ByteBuffer.wrap(annotationDefault),
sun.misc.SharedSecrets.getJavaLangAccess().
getConstantPool(getDeclaringClass()),
getDeclaringClass());
if (result instanceof sun.reflect.annotation.ExceptionProxy)
throw new AnnotationFormatError("Invalid default: " + this);
return result;
}
Returns an array of arrays that represent the annotations on the formal parameters, in declaration order, of the method represented by this Method
object. (Returns an array of length zero if the underlying method is parameterless. If the method has one or more parameters, a nested array of length zero is returned for each parameter with no annotations.) The annotation objects contained in the returned arrays are serializable. The caller of this method is free to modify the returned arrays; it will have no effect on the arrays returned to other callers. Returns: an array of arrays that represent the annotations on the formal
parameters, in declaration order, of the method represented by this
Method object Since: 1.5
/**
* Returns an array of arrays that represent the annotations on the formal
* parameters, in declaration order, of the method represented by
* this {@code Method} object. (Returns an array of length zero if the
* underlying method is parameterless. If the method has one or more
* parameters, a nested array of length zero is returned for each parameter
* with no annotations.) The annotation objects contained in the returned
* arrays are serializable. The caller of this method is free to modify
* the returned arrays; it will have no effect on the arrays returned to
* other callers.
*
* @return an array of arrays that represent the annotations on the formal
* parameters, in declaration order, of the method represented by this
* Method object
* @since 1.5
*/
public Annotation[][] getParameterAnnotations() {
int numParameters = parameterTypes.length;
if (parameterAnnotations == null)
return new Annotation[numParameters][0];
Annotation[][] result = AnnotationParser.parseParameterAnnotations(
parameterAnnotations,
sun.misc.SharedSecrets.getJavaLangAccess().
getConstantPool(getDeclaringClass()),
getDeclaringClass());
if (result.length != numParameters)
throw new java.lang.annotation.AnnotationFormatError(
"Parameter annotations don't match number of parameters");
return result;
}
}