I want to create a list from a Class variable.
...
Class clazz = someObject.getClass();
List<clazz> myList = new ArrayList<clazz>(); // this line is a compilation error
...
How I can do it?
EDIT: I think you are getting it wrong. For example, if someObject is a Car, then myList type should be List<Car>. I want to treat my clazz variable as a type, in some way.
EDIT:
As Boris the Spider pointed out in the comments it actually is possible by using a generic method, but with a slight modification:
Instead of using the normal Class object, use the generic version Class<? extends [Type of someObject]>.
Example:
public static void main(String[] args){
Test t = new Test();
Class<? extends Test> testClass = t.getClass();
List<? extends Test> list = createListOfType(testClass);
}
private static <T> List<T> createListOfType(Class<T> type){
return new ArrayList<T>();
}
Of course you can also just go with
public static void main(String[] args){
Test t = new Test();
List<? extends Test> list = createListOfType(t);
}
private static <T> List<T> createListOfType(T element){
return new ArrayList<T>();
}
OLD POST:
You can't.
You can't, because Java needs to know the generic type you want to use for the ArrayList at compile time. It's possible to use Object as type though.
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