Executable

public abstract class Executable
extends AccessibleObject implements Member, GenericDeclaration

java.lang.Object
   ↳ java.lang.reflect.AccessibleObject
     ↳ java.lang.reflect.Executable


A shared superclass for the common functionality of Method and Constructor.

Summary

Inherited constants

Public methods

<T extends Annotation> T getAnnotation(Class<T> annotationClass)

Returns this element's annotation for the specified type if such an annotation is present, else null.

<T extends Annotation> T[] getAnnotationsByType(Class<T> annotationClass)

Returns annotations that are associated with this element.

Annotation[] getDeclaredAnnotations()

Returns annotations that are directly present on this element.

abstract Class<?> getDeclaringClass()

Returns the Class object representing the class or interface that declares the executable represented by this object.

abstract 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.

abstract int getModifiers()

Returns the Java language modifiers for the executable represented by this object.

abstract String getName()

Returns the name of the executable represented by this object.

abstract 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.

abstract Class[]<?> getParameterTypes()

Returns an array of Class objects that represent the formal parameter types, in declaration order, of the executable represented by this object.

Parameter[] getParameters()

Returns an array of Parameter objects that represent all the parameters to the underlying executable represented by this object.

abstract 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.

final boolean isAnnotationPresent(Class<? extends Annotation> annotationType)

Returns true if an annotation for the specified type is present on this element, else false.

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.

abstract String toGenericString()

Returns a string describing this Executable, including any type parameters.

Inherited methods

Public methods

getAnnotation

added in API level 26
T getAnnotation (Class<T> annotationClass)

Returns this element's annotation for the specified type if such an annotation is present, else null.

Parameters
annotationClass Class: the Class object corresponding to the annotation type

Returns
T this element's annotation for the specified annotation type if present on this element, else null

Throws
NullPointerException

getAnnotationsByType

T[] getAnnotationsByType (Class<T> annotationClass)

Returns annotations that are associated with this element. If there are no annotations associated with this element, the return value is an array of length 0. The difference between this method and getAnnotation(Class) is that this method detects if its argument is a repeatable annotation type (JLS 9.6), and if so, attempts to find one or more annotations of that type by "looking through" a container annotation. The caller of this method is free to modify the returned array; it will have no effect on the arrays returned to other callers.

Parameters
annotationClass Class: the Class object corresponding to the annotation type

Returns
T[] all this element's annotations for the specified annotation type if associated with this element, else an array of length zero

Throws
NullPointerException

getDeclaredAnnotations

added in API level 26
Annotation[] getDeclaredAnnotations ()

Returns annotations that are directly present on this element. This method ignores inherited annotations. If there are no annotations directly present on this element, the return value is an array of length 0. The caller of this method is free to modify the returned array; it will have no effect on the arrays returned to other callers.

Returns
Annotation[] annotations directly present on this element

getDeclaringClass

added in API level 26
Class<?> getDeclaringClass ()

Returns the Class object representing the class or interface that declares the executable represented by this object.

Returns
Class<?> an object representing the declaring class of the underlying member

getExceptionTypes

added in API level 26
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. Returns an array of length 0 if the executable declares no exceptions in its throws clause.

Returns
Class[]<?> the exception types declared as being thrown by the executable this object represents

getGenericExceptionTypes

added in API level 26
Type[] getGenericExceptionTypes ()

Returns an array of 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.

Returns
Type[] an array of Types that represent the exception types thrown by the underlying executable

Throws
GenericSignatureFormatError if the generic method signature does not conform to the format specified in The Java™ Virtual Machine Specification
TypeNotPresentException if the underlying executable's throws clause refers to a non-existent type declaration
MalformedParameterizedTypeException if the underlying executable's throws clause refers to a parameterized type that cannot be instantiated for any reason

getGenericParameterTypes

added in API level 26
Type[] getGenericParameterTypes ()

Returns an array of 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.

Returns
Type[] an array of Types that represent the formal parameter types of the underlying executable, in declaration order

Throws
GenericSignatureFormatError if the generic method signature does not conform to the format specified in The Java™ Virtual Machine Specification
TypeNotPresentException if any of the parameter types of the underlying executable refers to a non-existent type declaration
MalformedParameterizedTypeException if any of the underlying executable's parameter types refer to a parameterized type that cannot be instantiated for any reason

getModifiers

added in API level 26
int getModifiers ()

Returns the Java language modifiers for the executable represented by this object.

Returns
int the Java language modifiers for the underlying member

getName

added in API level 26
String getName ()

Returns the name of the executable represented by this object.

Returns
String the simple name of the underlying member

getParameterAnnotations

added in API level 26
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. 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.

Returns
Annotation[][] an array of arrays that represent the annotations on the formal and implicit parameters, in declaration order, of the executable represented by this object

getParameterCount

added in API level 26
int getParameterCount ()

Returns the number of formal parameters (whether explicitly declared or implicitly declared or neither) for the executable represented by this object.

Returns
int The number of formal parameters for the executable this object represents

getParameterTypes

added in API level 26
Class[]<?> getParameterTypes ()

Returns an array of 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.

Returns
Class[]<?> the parameter types for the executable this object represents

getParameters

added in API level 26
Parameter[] getParameters ()

Returns an array of Parameter objects that represent all the parameters to the underlying executable represented by this object. Returns an array of length 0 if the executable has no parameters.

The parameters of the underlying executable do not necessarily have unique names, or names that are legal identifiers in the Java programming language (JLS 3.8).

Returns
Parameter[] an array of Parameter objects representing all the parameters to the executable this object represents.

Throws
MalformedParametersException if the class file contains a MethodParameters attribute that is improperly formatted.

getTypeParameters

added in API level 26
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.

Returns
TypeVariable[]<?> 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

isAnnotationPresent

added in API level 1
boolean isAnnotationPresent (Class<? extends Annotation> annotationType)

Returns true if an annotation for the specified type is present on this element, else false. This method is designed primarily for convenient access to marker annotations.

The truth value returned by this method is equivalent to: getAnnotation(annotationClass) != null

The body of the default method is specified to be the code above.

Parameters
annotationType Class: the Class object corresponding to the annotation type

Returns
boolean true if an annotation for the specified annotation type is present on this element, else false

isSynthetic

added in API level 26
boolean isSynthetic ()

Returns true if this executable is a synthetic construct; returns false otherwise.

Returns
boolean true if and only if this executable is a synthetic construct as defined by The Java™ Language Specification.

isVarArgs

added in API level 26
boolean isVarArgs ()

Returns true if this executable was declared to take a variable number of arguments; returns false otherwise.

Returns
boolean true if an only if this executable was declared to take a variable number of arguments.

toGenericString

added in API level 26
String toGenericString ()

Returns a string describing this Executable, including any type parameters.

Returns
String a string describing this Executable, including any type parameters