Class and Generics ?

[Edward Chen]

if I only have a Class, how to use generics ?

Like this....

Class myClass = ....

List<myClass> myList = (List<myClass>)anotherList;

But this can't pass compiler, how to work out ?

Thanks

[Gavin Tranter]

Hi,
Generics uses Type information not the names of instances.
Type information is the name of a class, suct as String or 2DPoint.

Therefore in your example you should replace myClass with Class, as Class is the type of the objects you plan to store in the list.

hope this helps
Gavin

[Edward Chen]

Gavin Tranter wrote:
Therefore in your example you should replace myClass with Class, as Class is the type of the objects you plan to store in the list.

Are you saying

List<Class> peopleList = (List<Class>)anotherList;

But this can't help me. My goal is to dynamically cast a list to another list based on its Class type.

The perfect solution for me will be something like this

public void cast(List oneList, Class thisClass){    
   List<thisClass.Type> newList = (List<thisClass.Type>)oneList;
}

cast(myList, People.class); // cast to a People list

How to work out ?

Thanks.

[Ernest Friedman-Hill]

Generics are a compile-time only construct. At runtime, a List contains only Objects; therefore your request really doesn't make any sense; is it not necessary.

[Mike Simmons]

This isn't exactly what you asked for, but you might like Collections.checkedList(). It's not "casting" , but it creates a list that can only contain the specified type. Unless the list already contained some other type within it, in which case you'll get a ClassCastException if you try to access it.