实施不起作用

Question

我有4节课.一个是驱动程序类,一个是接口和两个子类.这是Interface类:

public interface Speaker {
    public void speak();
    public void announce(String announcement);
}

这是驱动程序类:

public abstract class SpeakerDriver implements Speaker {
    public static void main (String [] args) {
        Speaker ref;
        Politician poli = new Politician("George Bush");
        Lecturer lect = new Lecturer("Professor Cross");
        Pastor past = new Pastor ("P.M. Smith");

        ref = poli;
        ref = lect;
        ref = past;

        System.out.println();
        System.out.println(lect);
        System.out.println(past);   
    }
}

这些是两个子类:

public class Pastor implements Speaker {
    protected String announcement;

    public Pastor (String name) {       
    }

    @Override
    public void speak() {   
    }

    @Override
    public void announce(String announc) {
        System.out.println("I am the pastor at CCBC."); 
    }
}

public class Lecturer implements Speaker {
    protected String announcement;

    public Lecturer(String name) {
    }

    @Override
    public void speak() {
    }

    @Override
    public void announce(String announcement) {     
        System.out.println("I am the lecturer at CCBC");    
    }
}

我的问题是,我的实现有什么问题,使输出看起来像这样:

Lecturer@a90653
Pastor@de6ced

当它们应该包含println中的文本时.

Answer 1

您正在使用以下语句打印对象:

System.out.println(lect);

你可能打算在对象上调用一个函数:

lect.announce();

另请注意,您的驱动程序类实际上并不需要实现'Speaker'接口,而且以下语句中,前两个有效地完成了任何操作:

ref = poli;
ref = lect;
ref = past;