Can't get extended class to work with asbstract class

Question

I am having trouble working an extended class to work with my base abstract class. I keep getting this error message: "Fiction.java:4: invalid method declaration; return type required" public FictionBook()" Can someone give me some advice and or guidance on what I need to do? Thanks.
Here is my abstract class:
import javax.swing.*;
public abstract class Book
     protected String bookTitle;
     protected double bookPrice;
     public abstract double setPrice();
public Book()
          setBookPrice();
public double getBookPrice()
          return bookPrice;
public abstract void setBookPrice();
Here is the extended class that I have:
import javax.swing.*;
public class Fiction extends Book
     public Fiction()
          super();
          setBookPrice();
     public void setBookPrice();
          bookPrice = 24.95;
     public String toString()
          return("Fiction Book Price is $" + bookPrice);
}

Answer 1

Fiction.java:2: Fiction is not abstract and does not override abstract method setPrice() in BookThis one is pretty straightfoward: Book declares an abstract setPrice() method. In effect is promises "every concrete subclass of Book will define an implementation of setPrice()". But your Fiction class does not do this - it does not give an implementation of setPrice() even though as a Book it is required to do so. That is what the compiler is complaining about.
Fiction.java:6: call to super must be first statement in constructorThis one is slightly cryptic. If you use super() it must be as the first line of a constructor. You are using it as the first line of Fiction() so that looks OK - until you realise that Fiction() is not a constructor! That's because you declare it as a method returning void. Remove the "void" and the compiler will recognise it as a constructor and will be happy about your use of super().
Edited by: pbrockway2 on Sep 13, 2008 12:13 PM
Just a general point: it might be worth writing very brief comments for your abstract class to say what the methods are supposed to do. It isn't really clear what setBookPrice() is supposed to do given that it isn't passed any argument. Likewise setPrice(), how does it differ from setBookPrice()? what is the double value that it returns?