Most of the interfaces provided in the java.util.function package are specializations of the following four interfaces: Consumer<T>, Predicate<T>, Supplier<T>, and Function<T,R>. Let's review them and then look at a short overview of the other 39 standard functional interfaces.
Standard functional interfaces
Consumer<T>
By looking at the Consumer<T> interface definition, you can <indexentry content="standard functional interfaces:Consumer">guess already that this interface has an abstract method that accepts a parameter of type T and does not return anything. Well, when only one type is listed, it may define the type of the return value, as in the case of the Supplier...
