java根据类的一个属性对List去重

    public Page regRecord(RecordQueryParam recordQueryParam, PaobaPage paobaPage) {
        if(recordQueryParam.getCardId() == null && recordQueryParam.getOpenId() == null){
            throw new PbServiceException("请登录小程序后查询个人报名记录！");
        }else {
            Page map = playerRepository.regPage(recordQueryParam, paobaPage).map(
                    tuple2 -> {
                        tuple2._1();
                        ActivityVO activityVO = activityAssembler.E2V(tuple2._2());
                        UserActivityRegVO activityRegVO = new UserActivityRegVO();
                        BeanUtil.copyProperties(activityVO, activityRegVO);
                        activityRegVO.setUserRegTime(tuple2._1().getCreateTime());
                        return activityRegVO;
                    }
            );
            List content = map.getContent();
            List res = content.stream().collect(Collectors.collectingAndThen(
                    Collectors.toCollection(() -> new TreeSet<>(Comparator.comparing(UserActivityRegVO::getActId))), ArrayList::new
            ));

            return new PageImpl<>(res,PageRequest.of(paobaPage.getPn(), paobaPage.getPs()),map.getTotalElements());
        }
    }

使用流操作去重：

content.stream().collect(Collectors.collectingAndThen(
                    Collectors.toCollection(() -> new TreeSet<>(Comparator.comparing(UserActivityRegVO::getActId))), ArrayList::new
            ));

记录一下。