de.unkrig.commons.lang.protocol

Class Functions

java.lang.Object

de.unkrig.commons.lang.protocol.Functions

public final class Functions
extends java.lang.Object

Various Function- and FunctionWhichThrows-related utility methods.

Method Summary

Modifier and Type	Method and Description
static <I,O,EX extends java.lang.RuntimeException> Function<I,O>	asFunction(FunctionWhichThrows<? super I,? extends O,EX> source) Converts a FunctionWhichThrows into a Function.
static <I,O,EX extends java.lang.Throwable> FunctionWhichThrows<I,O,EX>	asFunctionWhichThrows(Function<? super I,? extends O> source) Converts a Function into a FunctionWhichThrows.
static <O,I extends O> Function<I,O>	identity()
static <I,O,EX extends java.lang.Throwable> Function<I,O>	ignoreExceptions(java.lang.Class<EX> exceptionClass, FunctionWhichThrows<I,O,EX> delegate, O defaultValue) Wraps the delegate such that its declared exception is caught, ignored, and the defaultValue is returned.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

identity

public static <O,I extends O> Function<I,O> identity()

Returns:

A Function that transforms any object reference to itself.

asFunctionWhichThrows

public static <I,O,EX extends java.lang.Throwable> FunctionWhichThrows<I,O,EX> asFunctionWhichThrows(Function<? super I,? extends O> source)

Converts a Function into a FunctionWhichThrows.

That is possible iff:

• The target's input type is a subclass of the source's input type, and
• The source's output type is a subclass of the target's output type.

Type Parameters:

I - The functions' input type

O - The functions' output type

EX - The target function's exception

asFunction

public static <I,O,EX extends java.lang.RuntimeException> Function<I,O> asFunction(FunctionWhichThrows<? super I,? extends O,EX> source)

Converts a FunctionWhichThrows into a Function.

That is possible iff:

• The target's input type is a subclass of the source's input type, and
• The source's output type is a subclass of the target's output type
• The source's exception is a subclass of RuntimeException.

Type Parameters:

I - The functions' input type

O - The functions' output type

EX - The source function's exception

ignoreExceptions

public static <I,O,EX extends java.lang.Throwable> Function<I,O> ignoreExceptions(java.lang.Class<EX> exceptionClass,
                                                                                  FunctionWhichThrows<I,O,EX> delegate,
                                                                                  @Nullable
                                                                                  O defaultValue)

Wraps the delegate such that its declared exception is caught, ignored, and the defaultValue is returned.