java-按多字段排序

@Data
@AllArgsConstructor
private static class Testsort {
		private String parentId;

		private String sort;
}

public static void main(String[] args) {
        Testsort vo1 = new Testsort("3", "1");
        Testsort vo2 = new Testsort("4", "1");
        Testsort vo3 = new Testsort("3", "3");
        Testsort vo4 = new Testsort("2", "1");
        Testsort vo5 = new Testsort("4", "2");
        Testsort vo6 = new Testsort("3", "2");
        List list = new ArrayList<>();
        list.add(vo1);
        list.add(vo2);
        list.add(vo3);
        list.add(vo4);
        list.add(vo5);
        list.add(vo6);

		Collections.sort(list, new Comparator() {
            @Override
            public int compare(Testsort o1, Testsort o2) {
                int i = o1.getParentId().compareTo(o2.getParentId());
                if (i != 0) {
                    return i;
                }
                return o1.getSort().compareTo(o2.getSort());
            }
        });

        list.forEach(v -> {
            System.out.print(v.getParentId());
            System.out.print("--");
            System.out.println(v.getSort());
        });
		
		//lambda写法： 
		details.sort(Comparator.comparing(Testsort::getParentId).thenComparingInt(Testsort::getSort));
    }