Module java.base
Package java.lang.reflect

Class Executable

    • Method Detail

      • getDeclaringClass

        public abstract Class<?> getDeclaringClass()
        Returns theClass object representing the class or interface that declares the executable represented by this object.
        Specified by:
        getDeclaringClass in interface Member
        Returns:
        an object representing the declaring class of the underlying member
      • getName

        public abstract String getName()
        Returns the name of the executable represented by this object.
        Specified by:
        getName in interface Member
        Returns:
        the simple name of the underlying member
      • getModifiers

        public abstract int getModifiers()
        Returns the Java languagemodifiers for the executable represented by this object.
        Specified by:
        getModifiers in interface Member
        Returns:
        the Java language modifiers for the underlying member
        See Also:
        Modifier
      • getTypeParameters

        public abstract TypeVariable<?>[] getTypeParameters()
        Returns an array ofTypeVariable objects that represent the type variables declared by the generic declaration represented by thisGenericDeclaration object, in declaration order. Returns an array of length 0 if the underlying generic declaration declares no type variables.
        Specified by:
        getTypeParameters in interface GenericDeclaration
        Returns:
        an array ofTypeVariable 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 inThe Java™ Virtual Machine Specification
      • getParameterTypes

        public abstract Class<?>[] getParameterTypes()
        Returns an array ofClass 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:
        the parameter types for the executable this object represents
      • getParameterCount

        public int getParameterCount()
        Returns the number of formal parameters (whether explicitly declared or implicitly declared or neither) for the executable represented by this object.
        Returns:
        The number of formal parameters for the executable this object represents
      • getGenericParameterTypes

        public Type[] getGenericParameterTypes()
        Returns an array ofType 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, theType 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:
        an array ofTypes 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 inThe 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
      • getParameters

        public Parameter[] getParameters()
        Returns an array ofParameter 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:
        an array ofParameter 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.
      • getExceptionTypes

        public abstract Class<?>[] getExceptionTypes()
        Returns an array ofClass 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:
        the exception types declared as being thrown by the executable this object represents
      • getGenericExceptionTypes

        public Type[] getGenericExceptionTypes()
        Returns an array ofType 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 itsthrows clause.

        If an exception type is a type variable or a parameterized type, it is created. Otherwise, it is resolved.

        Returns:
        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 inThe Java™ Virtual Machine Specification
        TypeNotPresentException - if the underlying executable'sthrows clause refers to a non-existent type declaration
        MalformedParameterizedTypeException - if the underlying executable'sthrows clause refers to a parameterized type that cannot be instantiated for any reason
      • toGenericString

        public abstract String toGenericString()
        Returns a string describing thisExecutable, including any type parameters.
        Returns:
        a string describing thisExecutable, including any type parameters
      • isVarArgs

        public boolean isVarArgs()
        Returnstrue if this executable was declared to take a variable number of arguments; returnsfalse otherwise.
        Returns:
        true if an only if this executable was declared to take a variable number of arguments.
      • isSynthetic

        public boolean isSynthetic()
        Returnstrue if this executable is a synthetic construct; returnsfalse otherwise.
        Specified by:
        isSynthetic in interface Member
        Returns:
        true if and only if this executable is a synthetic construct as defined byThe Java™ Language Specification.
        SeeThe Java™ Language Specification:
        13.1 The Form of a Binary
      • getParameterAnnotations

        public abstract Annotation[][] getParameterAnnotations()
        Returns an array of arrays ofAnnotations that represent the annotations on the formal parameters, in declaration order, of theExecutable 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 theExecutable 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. SeeParameter for more information.
        Returns:
        an array of arrays that represent the annotations on the formal and implicit parameters, in declaration order, of the executable represented by this object
        See Also:
        Parameter,AnnotatedElement.getAnnotations()
      • getAnnotation

        public <T extendsAnnotation> T getAnnotation​(Class<T> annotationClass)
        Returns this element's annotation for the specified type if such an annotation ispresent, else null.
        Specified by:
        getAnnotation in interface AnnotatedElement
        Overrides:
        getAnnotation in class AccessibleObject
        Type Parameters:
        T - the type of the annotation to query for and return if present
        Parameters:
        annotationClass - the Class object corresponding to the annotation type
        Returns:
        this element's annotation for the specified annotation type if present on this element, else null
        Throws:
        NullPointerException - if the given annotation class is null
      • getAnnotationsByType

        public <T extendsAnnotation> T[] getAnnotationsByType​(Class<T> annotationClass)
        Returns annotations that areassociated with this element. If there are no annotationsassociated with this element, the return value is an array of length 0. The difference between this method andAnnotatedElement.getAnnotation(Class) is that this method detects if its argument is arepeatable 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.
        Specified by:
        getAnnotationsByType in interface AnnotatedElement
        Overrides:
        getAnnotationsByType in class AccessibleObject
        Type Parameters:
        T - the type of the annotation to query for and return if present
        Parameters:
        annotationClass - the Class object corresponding to the annotation type
        Returns:
        all this element's annotations for the specified annotation type if associated with this element, else an array of length zero
        Throws:
        NullPointerException - if the given annotation class is null
      • getAnnotatedReturnType

        public abstract AnnotatedType getAnnotatedReturnType()
        Returns anAnnotatedType object that represents the use of a type to specify the return type of the method/constructor represented by this Executable. If thisExecutable object represents a constructor, the AnnotatedType object represents the type of the constructed object. If thisExecutable object represents a method, the AnnotatedType object represents the use of a type to specify the return type of the method.
        Returns:
        an object representing the return type of the method or constructor represented by thisExecutable
      • getAnnotatedReceiverType

        public AnnotatedType getAnnotatedReceiverType()
        Returns anAnnotatedType object that represents the use of a type to specify the receiver type of the method/constructor represented by thisExecutable object. The receiver type of a method/constructor is available only if the method/constructor has a receiver parameter (JLS 8.4.1). If this Executable objectrepresents an instance method or represents a constructor of an inner member class, and the method/constructoreither has no receiver parameter or has a receiver parameter with no annotations on its type, then the return value is anAnnotatedType object representing an element with no annotations. If thisExecutable object represents a static method or represents a constructor of a top level, static member, local, or anonymous class, then the return value is null.
        Returns:
        an object representing the receiver type of the method or constructor represented by thisExecutable ornull if thisExecutable can not have a receiver parameter
      • getAnnotatedParameterTypes

        public AnnotatedType[] getAnnotatedParameterTypes()
        Returns an array ofAnnotatedType objects that represent the use of types to specify formal parameter types of the method/constructor represented by this Executable. The order of the objects in the array corresponds to the order of the formal parameter types in the declaration of the method/constructor. Returns an array of length 0 if the method/constructor declares no parameters.
        Returns:
        an array of objects representing the types of the formal parameters of the method or constructor represented by thisExecutable
      • getAnnotatedExceptionTypes

        public AnnotatedType[] getAnnotatedExceptionTypes()
        Returns an array ofAnnotatedType objects that represent the use of types to specify the declared exceptions of the method/constructor represented by this Executable. The order of the objects in the array corresponds to the order of the exception types in the declaration of the method/constructor. Returns an array of length 0 if the method/constructor declares no exceptions.
        Returns:
        an array of objects representing the declared exceptions of the method or constructor represented by this Executable