/*
* @(#)Method.java 1.50 04/06/22
*
* Copyright 2004 Sun Microsystems, Inc. All rights reserved.
* SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
*/
package java.lang.reflect;
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 <code>Method</code> 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</code> 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</code> 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 volatile Class securityCheckTargetClassCache;
// 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.
*/
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.
*/
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 <code>Class</code> object representing the class or interface
* that declares the method represented by this <code>Method</code> object.
*/
public Class<?> getDeclaringClass() {
return clazz;
}
/**
* Returns the name of the method represented by this <code>Method</code>
* object, as a <code>String</code>.
*/
public String getName() {
return name;
}
/**
* Returns the Java language modifiers for the method represented
* by this <code>Method</code> object, as an integer. The <code>Modifier</code> class should
* be used to decode the modifiers.
*
* @see Modifier
*/
public int getModifiers() {
return modifiers;
}
/**
* Returns an array of <tt>TypeVariable</tt> objects that represent the
* type variables declared by the generic declaration represented by this
* <tt>GenericDeclaration</tt> object, in declaration order. Returns an
* array of length 0 if the underlying generic declaration declares no type
* variables.
*
* @return an array of <tt>TypeVariable</tt> 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 <code>Class</code> object that represents the formal return type
* of the method represented by this <code>Method</code> object.
*
* @return the return type for the method this object represents
*/
public Class<?> getReturnType() {
return returnType;
}
/**
* Returns a <tt>Type</tt> object that represents the formal return
* type of the method represented by this <tt>Method</tt> object.
*
* <p>If the return type is a parameterized type,
* the <tt>Type</tt> 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 <tt>Type</tt> 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 <code>Class</code> objects that represent the formal
* parameter types, in declaration order, of the method
* represented by this <code>Method</code> 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 <tt>Type</tt> objects that represent the formal
* parameter types, in declaration order, of the method represented by
* this <tt>Method</tt> 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 <tt>Type</tt> 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 <code>Class</code> objects that represent
* the types of the exceptions declared to be thrown
* by the underlying method
* represented by this <code>Method</code> object. Returns an array of length
* 0 if the method declares no exceptions in its <code>throws</code> 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 <tt>Type</tt> objects that represent the
* exceptions declared to be thrown by this <tt>Method</tt> object.
* Returns an array of length 0 if the underlying method declares
* no exceptions in its <tt>throws</tt> clause.
*
* <p>If an exception type is a parameterized type, the <tt>Type</tt>
* 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
* <tt>throws</tt> clause refers to a non-existent type declaration
* @throws MalformedParameterizedTypeException if
* the underlying method's <tt>throws</tt> 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 <code>Method</code> against the specified object. Returns
* true if the objects are the same. Two <code>Methods</code> 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 <code>Method</code>. 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</code>. 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
* <tt>public</tt>, <tt>protected</tt> or <tt>private</tt> first,
* and then other modifiers in the following order:
* <tt>abstract</tt>, <tt>static</tt>, <tt>final</tt>,
* <tt>synchronized</tt> <tt>native</tt>.
*/
public String toString() {
try {
StringBuffer sb = new StringBuffer();
int mod = getModifiers();
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 <code>Method</code>, 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
* <tt>public</tt>, <tt>protected</tt> or <tt>private</tt> first,
* and then other modifiers in the following order:
* <tt>abstract</tt>, <tt>static</tt>, <tt>final</tt>,
* <tt>synchronized</tt> <tt>native</tt>.
*
* @return a string describing this <code>Method</code>,
* include type parameters
*
* @since 1.5
*/
public String toGenericString() {
try {
StringBuilder sb = new StringBuilder();
int mod = getModifiers();
if (mod != 0) {
sb.append(Modifier.toString(mod) + " ");
}
Type[] typeparms = getTypeParameters();
if (typeparms.length > 0) {
boolean first = true;
sb.append("<");
for(Type typeparm: typeparms) {
if (!first)
sb.append(",");
if (typeparm instanceof Class)
sb.append(((Class)typeparm).getName());
else
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++) {
sb.append((params[j] instanceof Class)?
Field.getTypeName((Class)params[j]):
(params[j].toString()) );
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 <code>Method</code>
* 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</code>
* 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</code> 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</code> with parameters
* <code>args</code>
*
* @exception IllegalAccessException if this <code>Method</code> 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.
*/
public Object invoke(Object obj, Object... args)
throws IllegalAccessException, IllegalArgumentException,
InvocationTargetException
{
if (!override) {
if (!Reflection.quickCheckMemberAccess(clazz, modifiers)) {
Class caller = Reflection.getCallerClass(1);
Class targetClass = ((obj == null || !Modifier.isProtected(modifiers))
? clazz
: obj.getClass());
if (securityCheckCache != caller ||
targetClass != securityCheckTargetClassCache) {
Reflection.ensureMemberAccess(caller, clazz, obj, modifiers);
securityCheckCache = caller;
securityCheckTargetClassCache = targetClass;
}
}
}
if (methodAccessor == null) acquireMethodAccessor();
return methodAccessor.invoke(obj, args);
}
/**
* Returns <tt>true</tt> if this method is a bridge
* method; returns <tt>false</tt> 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 <tt>true</tt> if this method was declared to take
* a variable number of arguments; returns <tt>false</tt>
* otherwise.
*
* @return <tt>true</tt> 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 <tt>true</tt> if this method is a synthetic
* method; returns <tt>false</tt> 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);
}
}
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];
public Annotation[] getDeclaredAnnotations() {
return declaredAnnotations().values().toArray(EMPTY_ANNOTATION_ARRAY);
}
private transient Map<Class, Annotation> declaredAnnotations;
private synchronized Map<Class, 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 <tt>Method</tt> 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 <tt>Method</tt> 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 <tt>Method</tt> 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;
}
}
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