public final class Method extends Executable
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.
| Modifier and Type | Method | Description |
|---|---|---|
boolean | equals(Object obj) | Compares this Method against the specified object. |
AnnotatedType | getAnnotatedReturnType() | Returns an AnnotatedType object that represents the use of a type to specify the return type of the method/constructor represented by this Executable. |
<T extends Annotation> | getAnnotation(Class<T> annotationClass) | Returns this element's annotation for the specified type if such an annotation is present, else null. |
Annotation[] | getDeclaredAnnotations() | Returns annotations that are directly present on this element. |
Class<?> | getDeclaringClass() | Returns the Class object representing the class or interface that declares the executable represented by this object. |
Object | getDefaultValue() | Returns the default value for the annotation member represented by this Method instance. |
Class<?>[] | getExceptionTypes() | Returns an array of Class objects that represent the types of exceptions declared to be thrown by the underlying executable represented by this object. |
Type[] | getGenericExceptionTypes() | Returns an array of Type objects that represent the exceptions declared to be thrown by this executable object. |
Type[] | getGenericParameterTypes() | Returns an array of Type objects that represent the formal parameter types, in declaration order, of the executable represented by this object. |
Type | getGenericReturnType() | Returns a Type object that represents the formal return type of the method represented by this Method object. |
int | getModifiers() | Returns the Java language modifiers for the executable represented by this object. |
String | getName() | Returns the name of the method represented by this Method object, as a String. |
Annotation[][] | getParameterAnnotations() | Returns an array of arrays of Annotations that represent the annotations on the formal parameters, in declaration order, of the Executable represented by this object. |
int | getParameterCount() | Returns the number of formal parameters (whether explicitly declared or implicitly declared or neither) for the executable represented by this object. |
Class<?>[] | getParameterTypes() | Returns an array of Class objects that represent the formal parameter types, in declaration order, of the executable represented by this object. |
Class<?> | getReturnType() | Returns a Class object that represents the formal return type of the method represented by this Method object. |
TypeVariable<Method>[] | 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. |
int | hashCode() | Returns a hashcode for this Method. |
Object | invoke(Object obj, Object... args) | Invokes the underlying method represented by this Method object, on the specified object with the specified parameters. |
boolean | isBridge() | Returns true if this method is a bridge method; returns false otherwise. |
boolean | isDefault() | Returns true if this method is a default method; returns false otherwise. |
boolean | isSynthetic() | Returns true if this executable is a synthetic construct; returns false otherwise. |
boolean | isVarArgs() | Returns true if this executable was declared to take a variable number of arguments; returns false otherwise. |
String | toGenericString() | Returns a string describing this Method, including type parameters. |
String | toString() | Returns a string describing this Method. |
getAnnotatedExceptionTypes, getAnnotatedParameterTypes, getAnnotatedReceiverType, getAnnotationsByType, getParametersgetAnnotations, getDeclaredAnnotation, getDeclaredAnnotationsByType, isAccessible, isAnnotationPresent, setAccessible, setAccessibleclone, finalize, getClass, notify, notifyAll, wait, wait, waitgetAnnotations, getDeclaredAnnotation, getDeclaredAnnotationsByType, isAnnotationPresentpublic Class<?> getDeclaringClass()
Class object representing the class or interface that declares the executable represented by this object.getDeclaringClass in interface MembergetDeclaringClass in class Executablepublic String getName()
Method object, as a String.getName in interface MembergetName in class Executablepublic int getModifiers()
getModifiers in interface MembergetModifiers in class ExecutableModifierpublic TypeVariable<Method>[] getTypeParameters()
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.getTypeParameters in interface GenericDeclarationgetTypeParameters in class ExecutableTypeVariable objects that represent the type variables declared by this generic declarationGenericSignatureFormatError - if the generic signature of this generic declaration does not conform to the format specified in The Java™ Virtual Machine Specificationpublic Class<?> getReturnType()
Class object that represents the formal return type of the method represented by this Method object.public Type getGenericReturnType()
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.
Type object that represents the formal return type of the underlying methodGenericSignatureFormatError - if the generic method signature does not conform to the format specified in The Java™ Virtual Machine SpecificationTypeNotPresentException - if the underlying method's return type refers to a non-existent type declarationMalformedParameterizedTypeException - if the underlying method's return typed refers to a parameterized type that cannot be instantiated for any reasonpublic Class<?>[] getParameterTypes()
Class objects that represent the formal parameter types, in declaration order, of the executable represented by this object. Returns an array of length 0 if the underlying executable takes no parameters.getParameterTypes in class Executablepublic int getParameterCount()
getParameterCount in class Executablepublic Type[] getGenericParameterTypes()
Type objects that represent the formal parameter types, in declaration order, of the executable represented by this object. Returns an array of length 0 if the underlying executable 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.
getGenericParameterTypes in class ExecutableTypes that represent the formal parameter types of the underlying executable, in declaration orderGenericSignatureFormatError - if the generic method signature does not conform to the format specified in The Java™ Virtual Machine SpecificationTypeNotPresentException - if any of the parameter types of the underlying executable refers to a non-existent type declarationMalformedParameterizedTypeException - if any of the underlying executable's parameter types refer to a parameterized type that cannot be instantiated for any reasonpublic Class<?>[] getExceptionTypes()
Class objects that represent the types of exceptions declared to be thrown by the underlying executable represented by this object. Returns an array of length 0 if the executable declares no exceptions in its throws clause.getExceptionTypes in class Executablepublic Type[] getGenericExceptionTypes()
Type objects that represent the exceptions declared to be thrown by this executable object. Returns an array of length 0 if the underlying executable declares no exceptions in its throws clause. If an exception type is a type variable or a parameterized type, it is created. Otherwise, it is resolved.
getGenericExceptionTypes in class ExecutableGenericSignatureFormatError - if the generic method signature does not conform to the format specified in The Java™ Virtual Machine SpecificationTypeNotPresentException - if the underlying executable's throws clause refers to a non-existent type declarationMalformedParameterizedTypeException - if the underlying executable's throws clause refers to a parameterized type that cannot be instantiated for any reasonpublic boolean equals(Object obj)
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.equals in class Objectobj - the reference object with which to compare.true if this object is the same as the obj argument; false otherwise.Object.hashCode(), HashMappublic int hashCode()
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.hashCode in class ObjectObject.equals(java.lang.Object), System.identityHashCode(java.lang.Object)public String toString()
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, default, static, final, synchronized, native, strictfp.
public String toGenericString()
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 public, protected or private first, and then other modifiers in the following order: abstract, default, static, final, synchronized, native, strictfp.
toGenericString in class ExecutableMethod, include type parameterspublic Object invoke(Object obj, Object... args) throws IllegalAccessException, IllegalArgumentException, InvocationTargetException
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.
obj - the object the underlying method is invoked fromargs - the arguments used for the method callobj with parameters argsIllegalAccessException - if this Method object is enforcing 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.public boolean isBridge()
true if this method is a bridge method; returns false otherwise.public boolean isVarArgs()
true if this executable was declared to take a variable number of arguments; returns false otherwise.isVarArgs in class Executabletrue if an only if this executable was declared to take a variable number of arguments.public boolean isSynthetic()
true if this executable is a synthetic construct; returns false otherwise.isSynthetic in interface MemberisSynthetic in class Executablepublic boolean isDefault()
true if this method is a default method; returns 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.public Object getDefaultValue()
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.Method instance.TypeNotPresentException - if the annotation is of type Class and no definition can be found for the default class value.public <T extends Annotation> T getAnnotation(Class<T> annotationClass)
getAnnotation in interface AnnotatedElementgetAnnotation in class ExecutableT - the type of the annotation to query for and return if presentannotationClass - the Class object corresponding to the annotation typeNullPointerException - if the given annotation class is nullpublic Annotation[] getDeclaredAnnotations()
getDeclaredAnnotations in interface AnnotatedElementgetDeclaredAnnotations in class Executablepublic Annotation[][] getParameterAnnotations()
Annotations that represent the annotations on the formal parameters, in declaration order, of the Executable represented by this object. Synthetic and mandated parameters (see explanation below), such as the outer "this" parameter to an inner class constructor will be represented in the returned array. If the executable has no parameters (meaning no formal, no synthetic, and no mandated parameters), a zero-length array will be returned. If the Executable 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. A compiler may add extra parameters that are implicitly declared in source ("mandated"), as well as parameters that are neither implicitly nor explicitly declared in source ("synthetic") to the parameter list for a method. See Parameter for more information.getParameterAnnotations in class ExecutableParameter, Parameter.getAnnotations()public AnnotatedType getAnnotatedReturnType()
AnnotatedType object that represents the use of a type to specify the return type of the method/constructor represented by this Executable. If this Executable object represents a constructor, the AnnotatedType object represents the type of the constructed object. If this Executable object represents a method, the AnnotatedType object represents the use of a type to specify the return type of the method.getAnnotatedReturnType in class ExecutableExecutable Submit a bug or feature
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