Is it possible to instantiate generic objects in Java as does in the following code fragment? I know that it is possible in C#. But, I haven not seen a similar mechanism yet in Java.
// Let T be a generic type.
T t = new T();
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1Possible duplicate: stackoverflow.com/questions/1090458/…Mike– Mike2010-10-27 13:09:01 +00:00Commented Oct 27, 2010 at 13:09
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2 Answers
No, that doesn't work in Java, due to type erasure. By the time that code is executing, the code doesn't know what T is.
See the Java Generics FAQ more more information about Java generics than you ever wanted :) - in particular, see the Type Erasure section.
If you need to know the type of T at execution time, for this or other reasons, you can store it in a Class<T> and take it in the constructor:
private Class<T> realTypeOfT;
public Foo(Class<T> clazz) {
realTypeOfT = clazz;
}
You can then call newInstance() etc.
Comments
I'm afraid not. Generic types in Java are erased - they're used at compile time, but aren't there at runtime (this is actually quite handy in places).
What you can do is to create a new instance from the Class object.
Class<T> myClass;
T t = myClass.newInstance();
