OlliN's

import java.lang.reflect.ParameterizedType;
import java.lang.reflect.Type;
 
public class Parameterized {
    public static void main(String[] args) {
        new SubDada();
        new SubSubDada();
    }
}
 
abstract class Dada<T> {
    private Class<T> typeOfT;
    public Dada() {
        this.typeOfT = getTypeOfT();
        System.out.println("typeOfT: " + this.typeOfT);
    }
    @SuppressWarnings("unchecked")
    private Class<T> getTypeOfT() {
        ParameterizedType pType = getDadaAsParameterizedType(getClass());
        return (Class<T>) pType.getActualTypeArguments()[0];
    }
    private ParameterizedType getDadaAsParameterizedType(Class<?> clazz) {
        Object gstype = clazz.getGenericSuperclass();
        if (gstype instanceof ParameterizedType) {
            ParameterizedType ptype = (ParameterizedType) gstype;
            Type rawtype = ptype.getRawType();
            if (Dada.class.equals(rawtype)) {
                return ptype;
            }
        }
        return getDadaAsParameterizedType(clazz.getSuperclass());
    }
}
 
class SubDada extends Dada<String> {
    public SubDada() {
    }
}
 
class SubSubDada extends SubDada {
    public SubSubDada() {
    }
}