案例：自定义Book类，里面包含name和price，按price排序(从大到小)。要求使用两种方式排序，有一个 Book[] books= 4本书对象。
使用前面学习过的传递实现Comparator接口匿名内部类，也称为定制排序。可以按照price (1)从大到小〔2)从小到大(3）按照书名长度从大到小

public class ArrayExercise {public static void main(String[] args) {Book[] books = new Book[4];books[0] = new Book("红楼梦", 100);books[1] = new Book("金瓶梅新", 90);books[2] = new Book("青年文摘2023", 5);books[3] = new Book("java从入门到放弃", 300);//Arrays.sort(books, new Comparator() {// 这里是对Book数组排序，因此o1和o2就是Book对象@Overridepublic int compare(Object o1, Object o2) {Book book1 = (Book) o1;Book book2 = (Book) o2;double pdiff = book2.getPrice()-book1.getPrice();//这里进行了一个转换if(pdiff > 0) {//如果发现结果和我们输出的不一致，就修改一下返回的1和-1return -1;} else if(pdiff < 0) {return 1;} else {return 0;}}});System.out.println(Arrays.toString(books));}
}class Book {private String name;private int price;public Book(String name, int price) {this.name = name;this.price = price;}public int getPrice() {return price;}@Overridepublic String toString() {return "Book{" +"name='" + name + '\'' +", price=" + price +'}';}
}