Package org.forgerock.util.promise

Class NeverThrowsException

java.lang.Object

java.lang.Throwable

java.lang.Exception

java.lang.RuntimeException

org.forgerock.util.promise.NeverThrowsException

All Implemented Interfaces:

Serializable

public final class NeverThrowsException
extends RuntimeException

The NeverThrowsException class is an uninstantiable placeholder exception which should be used for indicating that a Function or AsyncFunction never throws an exception (i.e. the function cannot fail).

See Also:

• Serialized Form

Method Summary

Modifier and Type	Method	Description
static <V, E extends Exception> Function<NeverThrowsException,V,E>	neverThrown()	Utility method returning an empty function, whose goal is to ease the transformation of a Promise type.
static <V, E extends Exception> AsyncFunction<NeverThrowsException,V,E>	neverThrownAsync()	Utility method returning an empty function, whose goal is to ease the transformation of a Promise type.

Methods inherited from class java.lang.Throwable

addSuppressed, fillInStackTrace, getCause, getLocalizedMessage, getMessage, getStackTrace, getSuppressed, initCause, printStackTrace, printStackTrace, printStackTrace, setStackTrace, toString

Methods inherited from class java.lang.Object

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

Method Details

neverThrown

public static <V,
E extends Exception>
Function<NeverThrowsException,V,E> neverThrown()

Utility method returning an empty function, whose goal is to ease the transformation of a Promise type. Its main usage will be as the second argument in Promise.then(Function, Function). The implementation of this function is just to throw an IllegalStateException : but it will never be invoked as an Exception of type NeverThrowsException will never be thrown.

Type Parameters:

V - The expected type of that function

E - The new Exception that can be thrown by this function.

Returns:

a function that will throw an IllegalStateException : but it will never be invoked as an Exception of type NeverThrowsException will never be thrown.

neverThrownAsync

public static <V,
E extends Exception>
AsyncFunction<NeverThrowsException,V,E> neverThrownAsync()

Utility method returning an empty function, whose goal is to ease the transformation of a Promise type. Its main usage will be as the second argument in Promise.thenAsync(AsyncFunction, AsyncFunction). The implementation of this function is just to return a promise of an IllegalStateException : but it will never be invoked as an Exception of type NeverThrowsException will never be thrown.

Type Parameters:

V - The expected type of that function

E - The new Exception that can be thrown by this function.

Returns:

an async function that will throw an IllegalStateException : but it will never be invoked as an Exception of type NeverThrowsException will never be thrown.