Java后端实现-元素拖动排序

小鱼儿 2022-10-23 04:59 447阅读 0赞

@ApiOperation(value = "板块拖动排序")
        @ApiImplicitParams({
                @ApiImplicitParam(name = "plateId1", value = "拖拽体"),
                @ApiImplicitParam(name = "plateId2", value = "参照体"),
                @ApiImplicitParam(name = "type", value = "实现类型1交换位置2挤压位置")
        })
        @PostMapping("plateSort")
        public ServiceResult<Object> plateSort(@RequestParam @NotNull Integer plateId1,
                                               @RequestParam @NotNull Integer plateId2,
                                               @RequestParam @NotNull @Max(2) @Min(1) Integer type) {
            //元素原地拖动
            if (plateId1.equals(plateId2)) {
                return success();
            }
    
            LambdaQueryWrapper<TiebaPlate> wrapper = new LambdaQueryWrapper<>();
            if (type == 1) {
                //两个元素交换位置
                wrapper
                        .eq(TiebaPlate::getId, plateId1)
                        .or()
                        .eq(TiebaPlate::getId, plateId2);
                List<TiebaPlate> list = tiebaPlateService.list(wrapper);
                int x = list.get(0).getOrderNum();
                int y = list.get(1).getOrderNum();
                list.get(0).setOrderNum(y);
                list.get(1).setOrderNum(x);
                //将collect更新到数据库
                boolean result = tiebaPlateService.updateBatchById(list);
                Assert.isTrue(result, "服务器异常");
    
                return success();
    
            } else if (type == 2) {
    
                if (plateId1 < plateId2) {
                    //将plateId1位置拖到plateId2位置下面
                    wrapper
                            .between(TiebaPlate::getId, plateId1, plateId2);
                    List<TiebaPlate> list = tiebaPlateService.list(wrapper);
                    List<TiebaPlate> collect = list.stream().sorted(Comparator.comparingInt(TiebaPlate::getOrderNum)).collect(Collectors.toList());
    
                    //排序标记
                    int[] orderNums = collect.stream().mapToInt(TiebaPlate::getOrderNum).toArray();
                    //将首位元素挪到末尾
                    TiebaPlate first = collect.get(0);
                    collect.remove(first);
                    collect.add(first);
    
                    //将集合元素和排序标记绑定
                    for (int i = 0; i < orderNums.length; i++) {
                        collect.get(i).setOrderNum(orderNums[i]);
                    }
    
                    //将collect更新到数据库
                    boolean result = tiebaPlateService.updateBatchById(collect);
                    Assert.isTrue(result, "服务器异常");
    
                    return success();
                } else {
                    //将plateId2位置拖到plateId1前面
                    wrapper
                            .between(TiebaPlate::getId, plateId2, plateId1);
                    List<TiebaPlate> list = tiebaPlateService.list(wrapper);
                    List<TiebaPlate> collect = list.stream().sorted(Comparator.comparingInt(TiebaPlate::getOrderNum)).collect(Collectors.toList());
                    //排序标记
                    int[] orderNums = collect.stream().mapToInt(TiebaPlate::getOrderNum).toArray();
    
                    //将末尾元素追加到首位
                    TiebaPlate last = collect.get(collect.size() - 1);
                    collect.remove(last);
                    Collections.reverse(collect);
                    collect.add(last);
                    Collections.reverse(collect);
    
                    //将集合元素和排序标记绑定
                    for (int i = 0; i < orderNums.length; i++) {
                        collect.get(i).setOrderNum(orderNums[i]);
                    }
    
                    //将collect更新到数据库
                    boolean result = tiebaPlateService.updateBatchById(collect);
                    Assert.isTrue(result, "服务器异常");
    
                    return success();
                }
            }
            return failure();
        }

思路:[https://www.jianshu.com/p/384debfe321d][https_www.jianshu.com_p_384debfe321d]

[https_www.jianshu.com_p_384debfe321d]: https://www.jianshu.com/p/384debfe321d