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/*
* Copyright (C) 2014 The Android Open Source Project
* Copyright (c) 1996, 2013, 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,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
package java.lang.reflect;
import sun.reflect.CallerSensitive;
import dalvik.annotation.optimization.FastNative;
import java.lang.annotation.Annotation;
import java.util.Comparator;
import libcore.reflect.Types;
import libcore.util.EmptyArray;
/**
* 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).
*
* 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 Executable {
// Android-changed: Extensive modifications made throughout the class for ART.
// Android-changed: Many fields and methods removed / modified.
// Android-removed: Type annotations runtime code. Not supported on Android.
// Android-removed: Declared vs actual parameter annotation indexes handling.
/**
* Orders methods by their name, parameters and return type.
*
* @hide
*/
public static final Comparator ORDER_BY_SIGNATURE = new Comparator() {
@Override public int compare(Method a, Method b) {
if (a == b) {
return 0;
}
int comparison = a.getName().compareTo(b.getName());
if (comparison == 0) {
comparison = a.compareMethodParametersInternal(b);
if (comparison == 0) {
// This is necessary for methods that have covariant return types.
Class aReturnType = a.getReturnType();
Class bReturnType = b.getReturnType();
if (aReturnType == bReturnType) {
comparison = 0;
} else {
comparison = aReturnType.getName().compareTo(bReturnType.getName());
}
}
}
return comparison;
}
};
private Method() {
}
@Override
boolean hasGenericInformation() {
// Android-changed: hasGenericInformation() implemented using Executable.
return super.hasGenericInformationInternal();
}
/**
* {@inheritDoc}
*/
@Override
public Class getDeclaringClass() {
// Android-changed: getDeclaringClass() implemented using Executable.
return super.getDeclaringClassInternal();
}
/**
* Returns the name of the method represented by this {@code Method}
* object, as a {@code String}.
*/
@Override
public String getName() {
// Android-changed: getName() implemented using Executable.
return getMethodNameInternal();
}
/**
* {@inheritDoc}
*/
@Override
public int getModifiers() {
// Android-changed: getModifiers() implemented using Executable.
return super.getModifiersInternal();
}
/**
* {@inheritDoc}
* @throws GenericSignatureFormatError {@inheritDoc}
* @since 1.5
*/
@Override
@SuppressWarnings({"rawtypes", "unchecked"})
public TypeVariable[] getTypeParameters() {
// Android-changed: getTypeParameters() partly implemented using Executable.
GenericInfo info = getMethodOrConstructorGenericInfoInternal();
return (TypeVariable[]) info.formalTypeParameters.clone();
}
/**
* 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() {
// Android-changed: getReturnType() implemented using Executable.
return getMethodReturnTypeInternal();
}
/**
* Returns a {@code Type} object that represents the formal return
* type of the method represented by this {@code Method} object.
*
* 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.
*
*
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
* @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() {
// Android-changed: getGenericReturnType() partly implemented using Executable.
return Types.getType(getMethodOrConstructorGenericInfoInternal().genericReturnType);
}
/**
* {@inheritDoc}
*/
@Override
public Class[] getParameterTypes() {
// Android-changed: getParameterTypes() partly implemented using Executable.
Class[] paramTypes = super.getParameterTypesInternal();
if (paramTypes == null) {
return EmptyArray.CLASS;
}
return paramTypes;
}
/**
* {@inheritDoc}
* @since 1.8
*/
public int getParameterCount() {
// Android-changed: getParameterTypes() implemented using Executable.
return super.getParameterCountInternal();
}
/**
* {@inheritDoc}
* @throws GenericSignatureFormatError {@inheritDoc}
* @throws TypeNotPresentException {@inheritDoc}
* @throws MalformedParameterizedTypeException {@inheritDoc}
* @since 1.5
*/
@Override
public Type[] getGenericParameterTypes() {
return super.getGenericParameterTypes();
}
/**
* {@inheritDoc}
*/
@Override
// Android-changed: getExceptionTypes() implemented natively.
@FastNative
public native Class[] getExceptionTypes();
/**
* {@inheritDoc}
* @throws GenericSignatureFormatError {@inheritDoc}
* @throws TypeNotPresentException {@inheritDoc}
* @throws MalformedParameterizedTypeException {@inheritDoc}
* @since 1.5
*/
@Override
public Type[] getGenericExceptionTypes() {
return super.getGenericExceptionTypes();
}
/**
* 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())) {
// Android-changed: Use getReturnType() instead of deleted returnType field
if (!getReturnType().equals(other.getReturnType()))
return false;
// Android-changed: Use getParameterTypes() instead of deleted parameterTypes field
return equalParamTypes(getParameterTypes(), other.getParameterTypes());
}
}
return false;
}
/**
* 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 {@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:
*
* 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
* {@code public}, {@code protected} or {@code private} first,
* and then other modifiers in the following order:
* {@code abstract}, {@code default}, {@code static}, {@code final},
* {@code synchronized}, {@code native}, {@code strictfp}.
*
* @return a string describing this {@code Method}
*
* @jls 8.4.3 Method Modifiers
*/
public String toString() {
// Android-changed: Use getParameterTypes() / getExceptionTypes() instead of deleted fields
return sharedToString(Modifier.methodModifiers(),
isDefault(),
getParameterTypes(),
getExceptionTypes());
}
@Override
void specificToStringHeader(StringBuilder sb) {
sb.append(getReturnType().getTypeName()).append(' ');
sb.append(getDeclaringClass().getTypeName()).append('.');
sb.append(getName());
}
/**
* 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.
*
* If this method was declared to take a variable number of
* arguments, instead of denoting the last parameter as
* "Type[]", it is denoted as
* "Type...".
*
* 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.
*
*
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 default}, {@code static}, {@code final},
* {@code synchronized}, {@code native}, {@code strictfp}.
*
* @return a string describing this {@code Method},
* include type parameters
*
* @since 1.5
*
* @jls 8.4.3 Method Modifiers
*/
@Override
public String toGenericString() {
return sharedToGenericString(Modifier.methodModifiers(), isDefault());
}
@Override
void specificToGenericStringHeader(StringBuilder sb) {
Type genRetType = getGenericReturnType();
sb.append(genRetType.getTypeName()).append(' ');
sb.append(getDeclaringClass().getTypeName()).append('.');
sb.append(getName());
}
/**
* 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.
*
*
If the underlying method is static, then the specified {@code obj}
* argument is ignored. It may be null.
*
*
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.
*
*
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.
*
* @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
* is enforcing 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
// Android-changed: invoke(Object, Object...) implemented natively.
@FastNative
public native Object invoke(Object obj, Object... args)
throws IllegalAccessException, IllegalArgumentException, InvocationTargetException;
/**
* 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() {
// Android-changed: isBridge() implemented using Executable.
return super.isBridgeMethodInternal();
}
/**
* {@inheritDoc}
* @since 1.5
*/
@Override
public boolean isVarArgs() {
return super.isVarArgs();
}
/**
* {@inheritDoc}
* @jls 13.1 The Form of a Binary
* @since 1.5
*/
@Override
public boolean isSynthetic() {
return super.isSynthetic();
}
/**
* Returns {@code true} if this method is a default
* method; returns {@code false} otherwise.
*
* A default method is a public non-abstract instance method, that
* is, a non-static method with a body, declared in an interface
* type.
*
* @return true if and only if this method is a default
* method as defined by the Java Language Specification.
* @since 1.8
*/
public boolean isDefault() {
// Android-changed: isDefault() implemented using Executable.
return super.isDefaultMethodInternal();
}
/**
* 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
*/
// Android-changed: isDefault() implemented natively.
@FastNative
public native Object getDefaultValue();
/**
* {@inheritDoc}
* @throws NullPointerException {@inheritDoc}
* @since 1.5
*/
public T getAnnotation(Class annotationClass) {
return super.getAnnotation(annotationClass);
}
/**
* {@inheritDoc}
* @since 1.5
*/
public Annotation[] getDeclaredAnnotations() {
return super.getDeclaredAnnotations();
}
/**
* {@inheritDoc}
* @since 1.5
*/
@Override
public Annotation[][] getParameterAnnotations() {
// Android-changed: getParameterAnnotations() implemented using Executable.
return super.getParameterAnnotationsInternal();
}
// Android-added: equalNameAndParameters(Method) for Proxy support.
/**
* Returns true if this and {@code method} have the same name and the same
* parameters in the same order. Such methods can share implementation if
* one method's return types is assignable to the other.
*
* @hide needed by Proxy
*/
boolean equalNameAndParameters(Method m) {
return equalNameAndParametersInternal(m);
}
}