Question

I have the following class:

public abstract class MyClass<T extends Object> {

    protected T createNewFromData(Reader reader){
        GSON.fromJSON(reader,T.class); // T.class isn't allowed :(
    }
}

How do I pass a Class<T> instance into there? Is there some wierd and wacky work around?

Is there a way to get a Class<T> reference other than from a pre-instantiated Object of type T? It won’t let me do this either:

T t = new T();
Class<T> klass = t.class;

Attempt #2

Interestingly, if I remove the “extends JSONOBjBase” from the class definition, I simply get an unchecked cast WARNING (no error). Is there another way to write how the cast is done?

Answer 1

Or you can send the Class as a constructor argument and use that object instead of trying to get T.class.

public abstract class MyClass<T extends Object> {

    private Class<T> klass;

    public MyClass(Class<T> klass) {
        this.klass = klass;
    }

    protected T createNewFromData(Reader reader){
        GSON.fromJSON(reader,klass); 
    }
}