javaclassgenericsargumentsloaded

Java how to pass a loaded class parameter type as a generic argument?

I would like to load a java class dynamically, and then add objects created with this class in an ObservableList<myLoadedClass> for example.

Class<?> thisClass = Class.forName("Point", true, classLoader);
Object iClass = thisClass.newInstance();
...
ObservableList<thisClass> data = FXCollections.observableArrayList();

The last line cause error

Cannot find symbol: class thisClass...

Thank you for your help.

Solution

  • Ok for the wildcard but then ...

    Class<?> thisClass = Class.forName("Point", true, classLoader);
Object iClass = thisClass.newInstance();
...
ObservableList<?> data = FXCollections.observableArrayList();
data.addAll(iClass);

    Last line cause: No suitable method found for addAll(Object).

    Any ideas?

    Five (or a bit more ;-) minutes later...

    Instead of wildcard, 'Object' made the trick. Inspired by This thread where they explain: "So a Collection of unknown type is not a collection that can take any type. It only takes the unknown type. And as we don't know that type (its unknown ;) ), we can never add a value, because no type in java is a subclass of the unknown type."

    So, for now, my solution is:

    Class<?> thisClass = Class.forName("Point", true, classLoader);
Object iClass = thisClass.newInstance();
...
ObservableList<Object> data = FXCollections.observableArrayList();
data.addAll(iClass);

// Sample Point class method
Method getXMethod = thisClass.getDeclaredMethod("getX");

System.out.println(getXMethod.invoke(data.get(0)));