排序注意为的情况null

@Data
@NoArgsConstructor
@AllArgsConstructor
static class Cat {
	private Integer id;
	private String name;
	private Integer p;
	public String toString() {

		return JSON.toJSONString(this,true);
	}
}
public static void main(String[] args) {
	List<Cat> catList = Arrays.asList(new Cat(2, "李四", null), new Cat(1, "周三", null),  new Cat(3, "王五", 2)
			, new Cat(4, "😫aa4", 7));
	catList.sort(((o1, o2) -> {
		if (o1.getP() == null && o2.getP() == null) {
			return 1;
		} else if (o1.getP() == null) {
			return 1;
		} else if (o2.getP() == null) {
			return -1;
		} else {
			return o1.p.compareTo(o2.p);
		}
	}));
	System.out.println(catList);
}