现有Book类,有属性成员,请定义成员的方法和构造方法,请编程实现使得书籍按价格降序输出

以下是一个简单的Book类的实现，包括成员变量和方法，以及构造方法。要按价格降序输出，我们可以使用Java中的Collections.sort()方法，并传入一个Comparator对象，以比较价格大小。

import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;

public class Book {
    private String title;
    private String author;
    private double price;

    public Book(String title, String author, double price) {
        this.title = title;
        this.author = author;
        this.price = price;
    }

    public String getTitle() {
        return title;
    }

    public String getAuthor() {
        return author;
    }

    public double getPrice() {
        return price;
    }

    public static void main(String[] args) {
        ArrayList<Book> books = new ArrayList<>();
        books.add(new Book("Java Programming", "John Smith", 29.99));
        books.add(new Book("Python Programming", "Jane Doe", 24.99));
        books.add(new Book("Data Structures", "Bob Johnson", 34.99));

        // Sort by price in descending order
        Collections.sort(books, new Comparator<Book>() {
            @Override
            public int compare(Book b1, Book b2) {
                return Double.compare(b2.getPrice(), b1.getPrice());
            }
        });

        // Print sorted books
        for (Book book : books) {
            System.out.println(book.getTitle() + " by " + book.getAuthor() + " - $" + book.getPrice());
        }
    }
}

输出结果：

Data Structures by Bob Johnson - $34.99
Java Programming by John Smith - $29.99
Python Programming by Jane Doe - $24.99