IT. Expert System.

Java Standard Edition (SE)

FunctionalInterface


java.lang

Annotation Type FunctionalInterface



  • @Documented
     @Retention(value=RUNTIME)
     @Target(value=TYPE)
    public @interface FunctionalInterface
    An informative annotation type used to indicate that an interface type declaration is intended to be a functional interface as defined by the Java Language Specification. Conceptually, a functional interface has exactly one abstract method. Since default methods have an implementation, they are not abstract. If an interface declares an abstract method overriding one of the public methods of java.lang.Object, that also does not count toward the interface's abstract method count since any implementation of the interface will have an implementation from java.lang.Object or elsewhere.

    Note that instances of functional interfaces can be created with lambda expressions, method references, or constructor references.

    If a type is annotated with this annotation type, compilers are required to generate an error message unless:

    • The type is an interface type and not an annotation type, enum, or class.
    • The annotated type satisfies the requirements of a functional interface.

    However, the compiler will treat any interface meeting the definition of a functional interface as a functional interface regardless of whether or not a FunctionalInterface annotation is present on the interface declaration.

    Since:
    1.8
    See The Java™ Language Specification:
    4.3.2. The Class Object, 9.8 Functional Interfaces, 9.4.3 Interface Method Body


Content

Android Reference

Java basics

Java Enterprise Edition (EE)

Java Standard Edition (SE)

SQL

HTML

PHP

CSS

Java Script

MYSQL

JQUERY

VBS

REGEX

C

C++

C#

Design patterns

RFC (standard status)

RFC (proposed standard status)

RFC (draft standard status)

RFC (informational status)

RFC (experimental status)

RFC (best current practice status)

RFC (historic status)

RFC (unknown status)

IT dictionary

License.
All information of this service is derived from the free sources and is provided solely in the form of quotations. This service provides information and interfaces solely for the familiarization (not ownership) and under the "as is" condition.
Copyright 2016 © ELTASK.COM. All rights reserved.
Site is optimized for mobile devices.
Downloads: 60 / 158770349. Delta: 0.03184 с