List列表按照对象进行排序

public class Product {
    private int discount;
    // 省略getter/setter方法
}

public class TestSortList {

    @Test
    public void test1(){
        List<Product> list = new ArrayList<>(3);
        Product p1 = new Product();
        p1.setDiscount(1);
        list.add(p1);

        Product p2 = new Product();
        p2.setDiscount(2);
        list.add(p2);

        Product p3 = new Product();
        p3.setDiscount(3);
        list.add(p3);

        Collections.sort(list, new Comparator<Product>() {
            @Override
            public int compare(Product o1, Product o2) {
                if(o1.getDiscount() > o2.getDiscount()){
                    return 1;
                } else if(o1.getDiscount() == o2.getDiscount()){
                    return 0;
                } else {
                    return -1;
                }
            }
        });

        for(Product product : list){
            System.out.println(product.getDiscount());
        }

    }
}

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Collections.sort(list, (o1, o2) -> {
     if(o2.getDiscount() > o1.getDiscount()){
         return 1;
     } else if(o1.getDiscount() == o2.getDiscount()){
         return 0;
     } else {
         return -1;
     }
 });