列表对象排序

程序员南飞2026-01-15 17:25

复制代码

@Data
class Product implements Comparator<Product>{
    String name;
    int popularity;
    int salesVolume;
    public String toString() {
        return String.format(java.util.Locale.ROOT, "[\"%s\", %d, %d]", name, popularity, salesVolume);
    }

    @Override
    public int compare(Product o1, Product o2) {
        if (o1.popularity != o2.popularity) {
            return o2.popularity - o1.popularity;
        } else if (o1.popularity == o2.popularity &&
            o1.salesVolume != o2.salesVolume) {
            return o2.salesVolume - o1.salesVolume;
        } else if (o1.popularity == o2.popularity &&
            o1.salesVolume == o2.salesVolume) {
            return o1.name.compareTo(o2.name);
        }
        return 0;
    }
}
public class test
{
    public static void main(String[] args) {
        Product product1 = new Product();
        product1.setName("product1");
        product1.setPopularity(10);
        product1.setSalesVolume(100);
        Product product2=new Product();
        product2.setName("product2");
        product2.setPopularity(20);
        product2.setSalesVolume(200);
        Product product3=new Product();
        product3.setName("product3");
        product3.setPopularity(20);
        product3.setSalesVolume(150);
        List<Product> list=new ArrayList<>();
        list.add(product1);
        list.add(product2);
        list.add(product3);
        System.out.println(list);
        list.sort(new Product());
        System.out.println(list);
    }
}

内部类写法

复制代码

Collections.sort(list, new Comparator<Product>() {
    @Override
    public int compare(Product o1, Product o2) {
        if (o1.popularity != o2.popularity) {
            return o2.popularity - o1.popularity;
        } else if (o1.popularity == o2.popularity &&
            o1.salesVolume != o2.salesVolume) {
            return o2.salesVolume - o1.salesVolume;
        } else if (o1.popularity == o2.popularity &&
            o1.salesVolume == o2.salesVolume) {
            return o1.name.compareTo(o2.name);
        }
        return 0;
    }
});
System.out.println(list);