Re: ArrayList called with specific object constructors

From:

Zio Jerry <ale.mito@tiscali.it>

Newsgroups:

comp.lang.java.programmer

Date:

Tue, 28 Apr 2009 16:30:47 -0700 (PDT)

Message-ID:

<700aac90-4911-41f2-ab7d-fce14f27e85a@d25g2000prn.googlegroups.com>

The idea is that you want to be able to use a factor of Integers (e.g.)
to fill a list of Numbers. The other way of doing this is to do this:
public <T> List<? super T> makeList(Factory<T> factory)

I prefer the other way.

That's clear, but I have problems using the interface Factory<T>

Also Robert code doesn't seem working because of course you can't
instantiate an interface:
List<Foo> lst = makeList(new Factory<Foo>() {
   Foo makeObject(String s1, String s2) {
     return new Foo(s1, s2);
   }

});

This is my code adapted with your suggestions:

//START
*** class calling generic method (implements Factory ?? Factory<T> ??)
***
....
ArrayList<Ric> ricList=xmlService.xml2objGEN(new Factory<Ric>());
....

*** class with GENERIC METHOD xml2objGEN() ***
....
private <T> ArrayList<T> xml2objGEN(Factory<T> factory){
        ArrayList<T> list=new ArrayList<T>();
        list.add(factory.makeObject("value1,"value2"));
        return list;
    }
*** interface Factory ***
public interface Factory<T> {
    public T makeObject(String s1, String s2);
}
//END

Thanks again,
Alessandro