Comments on: Java Generics: Instantiating Objects Of Type Parameter Without Passing Class Literal To Instance

By: Pim

Pim — Mon, 14 Feb 2011 10:19:04 +0000

html… :(
Nice solution.
Though I don’t get one thing.
If I have a generic container FooContainer[C] of Foo[T].
Where [C] is in fact Foo[T].
How can FooContainer create an instance of [C]?

By: Pim

Pim — Mon, 14 Feb 2011 10:18:14 +0000

Nice solution.
Though I don’t get one thing.
If I have a generic container FooContainer of Foo.
Where is in fact Foo.
How can FooContainer create an instance of ?

By: Pim

Pim — Mon, 14 Feb 2011 10:15:57 +0000

Nice solution.
Though I don’t get one thing.
If I have a generic container FooContainer of Foo.
Where is in fact Foo.
How can FooContainer create an instance of ?

By: travelar

travelar — Fri, 24 Dec 2010 12:05:38 +0000

“Fortunately, you can avoid such ugly code in some situations. In case where your class is a subclass of fully parameterized type you could get classes of actual type arguments using the Reflect API.”
How much is real?

By: Seweryn Niemiec

Seweryn Niemiec — Thu, 07 Feb 2008 11:07:55 +0000

thx for all comments.
btw, I have fixed some formatting issues which arouse with new web template.

By: Alex Miller

Alex Miller — Mon, 26 Mar 2007 12:53:04 +0000

Yeah, reified generics hopefully will be part of Java 7 – see http://tech.puredanger.com/java7#reified for some more info.

By: Seweryn Niemiec

Seweryn Niemiec — Mon, 26 Mar 2007 10:30:11 +0000

We have to wait for Java 7 for that.

By: Sam

Sam — Mon, 26 Mar 2007 09:40:22 +0000

You should really be able to do T.getClass()

By: Ricky Clarkson

Ricky Clarkson — Sun, 25 Mar 2007 15:10:29 +0000

A better way is to require a general Factory, which is what a Constructor would be if it wasn’t so tightly bound to the implementation of objects/classes in Java.

Then you just take a generic Factory, and call newInstance.

public [T] void doSomething(Factory[T] factory)
{
T t=factory.newInstance();
t.stuff();
}

I used [] to avoid HTML swallowing, as there’s no Preview button.