Uses of Interface

Packages that use Function
Provides classes that are fundamental to the design of the Java programming language.
HTTP Client and WebSocket APIs
Provides the classes and interfaces for the security framework.
Contains the collections framework, some internationalization support classes, a service loader, properties, random number generation, string parsing and scanning classes, base64 encoding and decoding, a bit array, and several miscellaneous utility classes.
Utility classes commonly useful in concurrent programming.
Functional interfaces provide target types for lambda expressions and method references.
Provides the classes and interfaces of the Java 2 platform's core logging facilities.
Classes for matching character sequences against patterns specified by regular expressions.
Classes to support functional-style operations on streams of elements, such as map-reduce transformations on collections.
Defines non-final APIs for concurrent programming.
Provides interfaces for creating tools, such as a Read-Eval-Print Loop (REPL), which interactively evaluate "snippets" of Java programming language code.