Commands.java

@FunctionalInterface
public interface Action<T extends Base> {
  void perform(T input);
}

public class Commands {
  private Map<Class<? extends Base>, Action<?>> actions = new HashMap<>();
  
  private <T extends Base> void addAction(Class<T> type, Action<T> action) {
    actions.put(type, action);
  }
  
  {
    addAction(Type1.class, input -> {
     // do something with input, which is of type 'Type1', here.
    });
    addAction(Type2.class, input -> {
     // ....
    });
  }
  
  public <T extends Base> void dispatch(T input) {
    Action<T> a = (Action<T>) actions.get(type.getClass());
    a.perform(input);
  }  
}

public class Type1 extends Base {
}

public class Type2 extends Base {
}