无论什么情况，只要是一组对象要排序，对象所在的类一定要实现Comparable接口

源代码：

import java.util.Arrays;

class Book implements Comparable{ //实现比较

private String title ;

private double price ;

public Book(String title,double price){

this.title = title ;

this.price = price ;

}

@Override

public String toString() {

return "书名："+this.title +",价格："+ this.price + "\n";

}

@Override

public int compareTo(Book o) { //Arrays.sort()会自动调用方法比较

if (this.price > o.price) {

return 1 ;

} else if (this.price < o.price) {

return -1 ;

}else {

return 0 ;

}

}

}

public class TestDemo {

public static void main(String[] args){

Book books[] = new Book[]{

new Book("Java开发",79.2),

new Book("J开发",78.2),

new Book("Ja开发",77.2),

new Book("Jav开发",76.2)

};

Arrays.sort(books);

System.out.println(Arrays.toString(books));

}

}

℃江