org.apache.commons.collections

Interface Transformer

All Known Implementing Classes:

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

public interface Transformer

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 invokation, returning a constant, cloning and returning the string value.

Since:

Commons Collections 1.0

Method Summary

Modifier and Type	Method and Description
java.lang.Object	transform(java.lang.Object input) Transforms the input object (leaving it unchanged) into some output object.

Method Detail

transform

java.lang.Object transform(java.lang.Object 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:

java.lang.ClassCastException - (runtime) if the input is the wrong class

java.lang.IllegalArgumentException - (runtime) if the input is invalid

FunctorException - (runtime) if the transform cannot be completed