通过在java8中传递Function来调用私有字段

Question

请在评论中帮我解决问题。我是java8的新手。如果你给我一些关键词进行搜索，那也会很棒。

public class aClass{
    public Function<String,String> f;
    private void doSomething(){
        System.out.println("done");
    }
    public void addF(Function<String,String> f){
        this.f = f;
    }
}

public class bClass{
    public String func(String str){
        System.out.println(str);
        //Call doSomething();
        //Can I do that? 
    }

    public static void main(String[] args){
        aClass a = new aClass();
        a.addF(this::func);
    }
}