File	Doc	Category	Size	Date	Package
Method.java	API Doc	Java SE 6 API	29955	Tue Jun 10 00:25:40 BST 2008	java.lang.reflect

Method

• java.lang.Object
  • java.lang.reflect.AccessibleObject

Fields Summary
private Class	clazz
private int	slot
private String	name
private Class	returnType
private Class[]	parameterTypes
private Class[]	exceptionTypes
private int	modifiers
private transient String	signature
private transient MethodRepository	genericInfo
private byte[]	annotations
private byte[]	parameterAnnotations
private byte[]	annotationDefault
private volatile sun.reflect.MethodAccessor	methodAccessor
private Method	root
private Class	securityCheckCache
private Class	securityCheckTargetClassCache
private static final int	LANGUAGE_MODIFIERS
private static final Annotation[]	EMPTY_ANNOTATION_ARRAY
private transient Map	declaredAnnotations

Constructors Summary

Method(Class declaringClass, String name, Class[] parameterTypes, Class returnType, Class[] checkedExceptions, int modifiers, int slot, String signature, byte[] annotations, byte[] parameterAnnotations, byte[] annotationDefault) Package-private constructor used by ReflectAccess to enable instantiation of these objects in Java code from the java.lang package via sun.reflect.LangReflectAccess. 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;

Methods Summary
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);
java.lang.reflect.Method	copy() 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. // 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;
private synchronized java.util.Map	declaredAnnotations() if (declaredAnnotations == null) { declaredAnnotations = AnnotationParser.parseAnnotations( annotations, sun.misc.SharedSecrets.getJavaLangAccess(). getConstantPool(getDeclaringClass()), getDeclaringClass()); } return declaredAnnotations;
public boolean	equals(java.lang.Object obj) 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. 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;
public T	getAnnotation(java.lang.Class annotationClass) throws NullPointerException {@inheritDoc} since 1.5 if (annotationClass == null) throw new NullPointerException(); return (T) declaredAnnotations().get(annotationClass);
public java.lang.annotation.Annotation[]	getDeclaredAnnotations() since 1.5 return declaredAnnotations().values().toArray(EMPTY_ANNOTATION_ARRAY);
public java.lang.Class	getDeclaringClass() Returns the Class object representing the class or interface that declares the method represented by this Method object. return clazz;
public java.lang.Object	getDefaultValue() 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. return the default value for the annotation member represented by this 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 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;
public java.lang.Class[]	getExceptionTypes() 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. return the exception types declared as being thrown by the method this object represents return (Class<?>[]) exceptionTypes.clone();
private sun.reflect.generics.factory.GenericsFactory	getFactory() // create scope and factory return CoreReflectionFactory.make(this, MethodScope.make(this));
public java.lang.reflect.Type[]	getGenericExceptionTypes() 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. 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 throws clause refers to a non-existent type declaration throws MalformedParameterizedTypeException if the underlying method's throws clause refers to a parameterized type that cannot be instantiated for any reason since 1.5 Type[] result; if (getGenericSignature() != null && ((result = getGenericInfo().getExceptionTypes()).length > 0)) return result; else return getExceptionTypes();
private sun.reflect.generics.repository.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
public java.lang.reflect.Type[]	getGenericParameterTypes() 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. 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 if (getGenericSignature() != null) return getGenericInfo().getParameterTypes(); else return getParameterTypes();
public java.lang.reflect.Type	getGenericReturnType() 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. return a 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 if (getGenericSignature() != null) { return getGenericInfo().getReturnType(); } else { return getReturnType();}
private java.lang.String	getGenericSignature() // Generics infrastructure return signature;
sun.reflect.MethodAccessor	getMethodAccessor() return methodAccessor;
public int	getModifiers() 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 Modifier return modifiers;
public java.lang.String	getName() Returns the name of the method represented by this Method object, as a String. return name;
public java.lang.annotation.Annotation[][]	getParameterAnnotations() 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. 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 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;
public java.lang.Class[]	getParameterTypes() 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. return the parameter types for the method this object represents return (Class<?>[]) parameterTypes.clone();
public java.lang.Class	getReturnType() Returns a Class object that represents the formal return type of the method represented by this Method object. return the return type for the method this object represents return returnType;
public java.lang.reflect.TypeVariable[]	getTypeParameters() 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. return an array of 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 if (getGenericSignature() != null) return (TypeVariable<Method>[])getGenericInfo().getTypeParameters(); else return (TypeVariable<Method>[])new TypeVariable[0];
public int	hashCode() 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. return getDeclaringClass().getName().hashCode() ^ getName().hashCode();
public java.lang.Object	invoke(java.lang.Object obj, java.lang.Object args) 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. 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 obj with parameters args exception IllegalAccessException if this 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. if (!override) { if (!Reflection.quickCheckMemberAccess(clazz, modifiers)) { Class caller = Reflection.getCallerClass(1); 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);
public boolean	isBridge() Returns true if this method is a bridge method; returns false otherwise. return true if and only if this method is a bridge method as defined by the Java Language Specification. since 1.5 return (getModifiers() & Modifier.BRIDGE) != 0;
public boolean	isSynthetic() Returns true if this method is a synthetic method; returns false otherwise. return true if and only if this method is a synthetic method as defined by the Java Language Specification. since 1.5 return Modifier.isSynthetic(getModifiers());
public boolean	isVarArgs() Returns true if this method was declared to take a variable number of arguments; returns false otherwise. return true if an only if this method was declared to take a variable number of arguments. since 1.5 return (getModifiers() & Modifier.VARARGS) != 0;
void	setMethodAccessor(sun.reflect.MethodAccessor accessor) methodAccessor = accessor; // Propagate up if (root != null) { root.setMethodAccessor(accessor); }
public java.lang.String	toGenericString() 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. return a string describing this Method, include type parameters since 1.5 try { StringBuilder sb = new StringBuilder(); int mod = getModifiers() & LANGUAGE_MODIFIERS; 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 + ">"; }
public java.lang.String	toString() 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. 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 + ">"; }