org.apache.commons.collections4

Interface Transformer<I,O>

Type Parameters:

I - the input type to the transformer

O - the output type from the transformer

All Known Implementing Classes:

ChainedTransformer, CloneTransformer, ClosureTransformer, ConstantTransformer, ExceptionTransformer, FactoryTransformer, IfTransformer, InstantiateTransformer, InvokerTransformer, MapTransformer, NOPTransformer, PredicateTransformer, StringValueTransformer, SwitchTransformer

Functional Interface:

This is a functional interface and can therefore be used as the assignment target for a lambda expression or method reference.

@FunctionalInterface
public interface Transformer<I,O>

Defines a functor interface implemented by classes that transform one object into another.

A Transformer converts the input object to the output object. The input object should be left unchanged. Transformers are typically used for type conversions, or extracting data from an object.

Standard implementations of common transformers are provided by TransformerUtils. These include method invocation, returning a constant, cloning and returning the string value.

Since:

1.0

Method Summary

Modifier and Type	Method and Description
O	transform(I input) Transforms the input object (leaving it unchanged) into some output object.

Method Detail

transform

O transform(I input)

Transforms the input object (leaving it unchanged) into some output object.

Parameters:

input - the object to be transformed, should be left unchanged

Returns:

a transformed object

Throws:

ClassCastException - (runtime) if the input is the wrong class

IllegalArgumentException - (runtime) if the input is invalid

FunctorException - (runtime) if the transform cannot be completed