The conversion from input object to output object is supported in commons-collections with the help of Transformer interface. The Transformers can be applied to get the output collection from input collection with the help of codes available in Commons-collections. BeanToPropertyTransformer is an example of Transformer that will convert a bean to its property value. This feature is able to extract a particular property from the input object and present it as output object.
If you try to find out a particular car model from many car users in a collection. The syntax is shown below:
// creating transformer BeanToPropertyValueTransformer transformer = new BeanToPropertyValueTransformer( "person.company.carmodel" ); // transforming Collection Collection carModel = CollectionUtils.collect( peopleCollection, transformer );