Question

How to call this pattern, and is there any existing apache-commons utility for this:

class Person {
    String getName();
}

List<Person> persons = ...;

// create a dynamic bean on the fly, which can be used as:
Object personXxxx = transformListOfBeans(Person.class, persons);
// so each of the bean properties now returns the list of the original property:
List<String> personNames = personXxxx.name;

// i.e. the transformation creates a new "type":
class PersonXxxx {
    List<String> getName();
}

How to call this kind of transformation? A proxy should keep the method signatures. So it is not a proxy, neither decorator.

Well, I can simply rename the generated property names to plural form, like:

personXxxx.names

This is no problem. I want to know if such pattern was already known so I don’t have to choose the appropriate words myself.

Answer 1

I don’t think a tool exists for this.
You have to code it :

List<String> names = new ArrayList<String>(persons.size());
for (Person person : persons) {
    names.add(person.getName());
}

Maybe you can use introspection to be more generic, but code is really simple.