Package org.apache.commons.collections4

Interface Transformer<T,R>

Type Parameters:
T - The type of the input to the function.
R - The type of the result of the function.
All Superinterfaces:
Function<T,R>
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<T,R> extends Function<T,R>
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 This will be deprecated in 5.0 in favor of Function.

  • Method Summary

    Modifier and Type
    Method
    Description
    default R
    apply(T t)
     
    R
    transform(T input)
    Transforms the input object into some output object.

    Methods inherited from interface java.util.function.Function

    andThen, compose

  • Method Details

    • apply

      default R apply(T t)
      Specified by:
      apply in interface Function<T,R>

    • transform

      R transform(T input)
      Transforms the input object into some output object.

      The input object SHOULD be left unchanged.

      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.