容器集合

怎么给集合内的数按顺序排序

package test2;

public class Book implements Comparable<Book> {
    private String name;
    private double price;

    public Book() {
        super();
    }

    public Book(String name, double price) {
        super();
        this.name = name;
        this.price = price;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    @Override
    public String toString() {
        return "Book [name=" + name + ", price=" + price + "]";
    }

    @Override
    public int hashCode() {
        final int prime = 31;
        int result = 1;
        result = prime * result + ((name == null) ? 0 : name.hashCode());
        return result;
    }

    @Override
    public boolean equals(Object obj) {
        if (this == obj)
            return true;
        if (obj == null)
            return false;
        if (getClass() != obj.getClass())
            return false;
        Book other = (Book) obj;
        if (name == null) {
            if (other.name != null)
                return false;
        } else if (!name.equals(other.name))
            return false;
        return true;
    }

    public double getPrice() {
        return price;
    }

    public void setPrice(double price) {
        this.price = price;
    }

    @Override
    public int compareTo(Book o) {
        if (this.price > o.getPrice()) {
            return 1;
        }
        if (this.price == o.getPrice()) {
            return 0;
        }
        return -1;
    }
}

package test2;

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

/**
 * Comparable
 * @author Administrator
 */
public class Test6 {

    public static void main(String[] args) {
        List<Book> list = new ArrayList<Book>();
        list.add(new Book("Java从入门到放弃", 78));
        list.add(new Book("Oracle数据库详解", 56));
        list.add(new Book("HTML入门", 3));
        list.add(new Book("三国演义", 108));
        Collections.sort(list);
        Collections.reverse(list);
        
        System.out.println(list);
    }

}

这样就可以按照书本后面的标价进行排序，从而获得一个价格从高到低的数组集合。