可以按照以下方式编写 Java 程序来创建 Fiction 和 NonFiction 两种书，并显示它们的字段：

public abstract class Book {
    private String title;
    private double price;
   
    public Book(String title, double price) {
        this.title = title;
        this.price = price;
    }
 
    public String getTitle() {
        return title;
    }
 
    public double getPrice() {
        return price;
    }
 
    public void setTitle(String title) {
        this.title = title;
    }
 
    public void setPrice(double price) {
        this.price = price;
    }
   
    public abstract String getBookType();
}
 
public class Fiction extends Book {
    public Fiction(String title, double price) {
        super(title, price);
    }
 
    public String getBookType() {
        return "Fiction";
    }
}
 
public class NonFiction extends Book {
    public NonFiction(String title, double price) {
        super(title, price);
    }
 
    public String getBookType() {
        return "Non-Fiction";
    }
}

public class Main {
    public static void main(String[] args) {
        Fiction fictionBook = new Fiction("Harry Potter", 29.99);
        NonFiction nonFictionBook = new NonFiction("Java for Beginners", 19.99);
        
        System.out.println(fictionBook.getTitle() + ", $" + fictionBook.getPrice() + ", " + fictionBook.getBookType());
        System.out.println(nonFictionBook.getTitle() + ", $" + nonFictionBook.getPrice() + ", " + nonFictionBook.getBookType());
    }
}

在这个例子中，我们定义了一个 Book 抽象类，其中包含通用字段和方法，然后我们继承 Book 类以创建 Fiction 和 NonFiction 书籍，并实现 getBookType() 方法来确定书籍类型。

在 Main 类中，我们创建了 Fiction 和 NonFiction 的实例，并使用它们的方法以显示其标题、价格和类型。运行程序后，输出结果应该为：

Harry Potter, $29.99, Fiction
Java for Beginners, $19.99, Non-Fiction