Package 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
    Description
    O
    transform(I input)
    Transforms the input object (leaving it unchanged) into some output object.

  • Method Details

    • 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