Java——类比较器

1、Product类

public class Product
{
    private int pid;
    private String name;
    private double price;

    public Product()
    {
        // TODO Auto-generated constructor stub
    }

    public Product(int pid, String name, double price)
    {
        this.pid = pid;
        this.name = name;
        this.price = price;
    }

    public int getPid()
    {
        return pid;
    }

    public void setPid(int pid)
    {
        this.pid = pid;
    }

    public String getName()
    {
        return name;
    }

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

    public double getPrice()
    {
        return price;
    }

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

}

2、类比较器：重写compare方法

public class MyCompare implements Comparator<Product> // 泛型<Product>表示该比较器只能比较Product类型
{

    @Override
    public int compare(Product p1, Product p2)
    {
        if (p1.getPrice() < p2.getPrice())
        {
            return -1;
        }
        else if (p1.getPrice() > p2.getPrice())
        {
            return 1;
        }
        else
        // 如果价格一样，按照id排序
        {
            if (p1.getPid() < p2.getPid())
            {
                return -1;
            }
            else if (p1.getPid() > p2.getPid())
            {
                return 1;
            }
            else
            {
                return 0;
            }
        }
    }

}

3、在ArrayList中使用比较器

public class ProductSort
{
    public static void main(String[] args)
    {
    
                Product p1 = new Product(1, "爆米花手机", 1000000.00);
        Product p2 = new Product(2, "iPhone 7s", 5088.00);
        Product p3 = new Product(3, "小米5s", 1999.99);
        Product p4 = new Product(4, "NIIT课程", 12800.00);
        Product p5 = new Product(5, "百达翡丽", 1980000.00);
        Product p6 = new Product(6, "宝玛electric", 1999.99);
        Product p7 = new Product(7, "TIIN课程", 12800.00);
                // 获得数组准备排序
        Product[] proArr = { p1, p2, p3, p4, p5, p6, p7 };

        Arrays.sort(proArr, new MyCompare());

        for (Product p : proArr)
        {
            System.out.println(p.getPid() + " " + p.getName() + " "
                    + p.getPrice());
        }
    }
}