Is there any way to create an instance of a generic using a Class variable?

Question

For example, is it possible to do something like this:

public void doSomething(Class clazz) {
    List<clazz> list = new ArrayList<clazz>();
    list.add(clazz.newInstance));
}

I know this doesn't work, but it shows what I'm trying to get at. Is there any way to parameterize the creation of generic class?

Thanks, Peter

How will you decide what to do with the stuff inside other than with instanceof? — BoltClock
– BoltClock, Commented Feb 4, 2011 at 15:34
The list is just an example of the kind of mechanics I am trying to use. The real application is different. — Risser
– Risser, Commented Feb 4, 2011 at 16:02

Peter Lawrey · Accepted Answer · 2011-02-04 15:33:52Z

6

You can try

public <T> void doSomething(Class<T> clazz) {
    List<T> list = new ArrayList<T>();
    list.add(clazz.newInstance());
}

answered Feb 4, 2011 at 15:33

Peter Lawrey

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2 Comments

public <T> void doSomething(Class<? extends T> clazz) { would probably be more useful. Although reflection is quite evil.

@Tom, it would be more useful if the method did something with the list (might be a good idea too) ;)