springboot+easyExcel 动态列表导出

1.pom依赖

    com.alibaba
    easyexcel
    3.0.0-beta2

2.导出传参类 

/**
 * @author hbj
 * @Date 2021/12/9 18:21
 * @Description
 * @Modified By
 */
@ApiModel(description = "导出传参类")
@Data
public class ExportDto {
    //接口访问路径
    @ApiModelProperty("接口访问路径")
    private String url;
    //请求方法；get或者post
    @ApiModelProperty("请求方法")
    private String method;
    //导出参数
    @ApiModelProperty("导出数据参数")
    private List exportParams;
    //搜索参数
    @ApiModelProperty("查询参数")
    private Map queryParams;
    //导出数量
    @ApiModelProperty("导出数量")
    private Long total;
    //导出文件名
    @ApiModelProperty("导出文件名")
    private String fileName;
}

@ApiModel(description = "导出数据参数")
@Data
public class ExportParamsDto {
    @ApiModelProperty("参数名（表头名字）")
    private String headName;
    @ApiModelProperty("对应字段")
    private String cloumn;
    /*@ApiModelProperty("时间参数格式（用于设置时间格式）")
    private String dateFormat;*/
    @ApiModelProperty("需要除以的数")
    private BigDecimal divideNum;
}

3.导出处理类 ExportDeal

/**
 * @author hbj
 * @Date 2021/12/17 17:37
 * @Description
 * @Modified By
 */
@Log4j2
public class ExportDeal {
    private ExcelWriter excelWriter;
    private List> heads;
    private WriteHandler writeHandler;
    private String fileName;
    private String sourName;
    private Long startTime;

    //初始化
    public ExportDeal(Map headMap, String fileName, HttpServletResponse response) throws Exception {
        this.sourName = fileName;
        startTime = System.currentTimeMillis();
        //添加响应头信息
        response.setContentType("application/vnd.openxmlformats-officedocument.spreadsheetml.sheet");
        response.setCharacterEncoding("utf-8");
        // 这里URLEncoder.encode可以防止中文乱码 当然和easyexcel没有关系
        fileName = URLEncoder.encode(fileName, "UTF-8").replaceAll("\\+", "%20");
        response.setHeader("Content-disposition", "attachment;filename*=utf-8''" + fileName + ".xlsx");
        //表头数组
        this.heads = head(headMap);
        //样式
        if (writeHandler == null) {
            this.writeHandler = new StyleWriteHandler();
            //this.writeHandler=new LongestMatchColumnWidthStyleStrategy();
        }
        //创建表格
        this.excelWriter = EasyExcel.write(response.getOutputStream()).head(heads).build();
        this.fileName = fileName;
        //log.info("表格【{}】初始化成功",sourName);
    }

    private ExportDeal() {
    }

    /**
     * 录入数据
     *
     * @param datas     录入的数据
     * @param sheetNo   第几页
     * @param sheetName 页名称
     * @param 
     */
    public  void loadData(List> datas, int sheetNo, String sheetName) {
        //录入数据
        WriteSheet writeSheet = EasyExcel.writerSheet(sheetNo).sheetName(sheetName).head(heads)
                .registerWriteHandler(writeHandler).build();
        excelWriter.write(datas, writeSheet);
    }

    /**
     * 根据http获取数据导出
     * @param dto
     * @param sheetNo
     * @param sheetName
     * @param 
     * @return
     */
    public  Result loadDataByHttp(ExportDto dto, int sheetNo, String sheetName) {
        String res;
        Map reqHeadMap = new HashMap<>();
        reqHeadMap.put("Content-Type", "application/json");
        reqHeadMap.put("Accept", "application/json");
        //最大导出10万
        if (dto.getTotal() > 10 * 10000) {
            dto.setTotal(10 * 10000L);
        }
        Map params = dto.getQueryParams();
        if (params == null) {
            params = new HashMap<>();
            params.put("pageSize", dto.getTotal());
            params.put("pageNo", 1);
        }
        if ("GET".equals(dto.getMethod())) {
            res = HttpsClient.doGet(dto.getUrl(), params, reqHeadMap);
        } else {
            res = HttpsClient.doPost(dto.getUrl(), JSONObject.toJSONString(params), reqHeadMap);
        }
        if (res != null) {
            Result result = JSON.parseObject(res, Result.class);
            if (result.getCode() == 0L && result.getMsg() == null) {
                JSONObject obj = JSON.parseObject(res);
                result = Result.restResult(obj.getLong("status"), obj.getString("error"));
            }
            JSONObject obj = ResultDealUtil.getData(result);
            if (obj != null && CollectionUtils.isNotEmpty(dto.getExportParams())) {
                PageVO page = JSON.parseObject(obj.toString(), PageVO.class);
                if (CollectionUtils.isNotEmpty(page.getRecords())) {
                    //表头map，key: 表头，value：字段
                    LinkedHashMap headMap = new LinkedHashMap<>();
                    dto.getExportParams().forEach(a -> headMap.put(a.getHeadName(), a));
                    List> datas = this.dataList(headMap, page.getRecords());
                    //录入导出数据
                    this.loadData(datas, sheetNo, sheetName);
                }
            } else if (ResultCode.SUCCESS.getCode() != result.getCode()) {
                log.error("导出失败：查询数据有误，{}", result);
                return result;
            }
        }
        return Result.ok();
    }

    //结束关闭数据
    public void close() {
        //刷新流
        excelWriter.finish();
        log.info("表格【{}】导出处理结束,耗时：{}ms", sourName, System.currentTimeMillis() - startTime);
    }

    private List> head(Map headMap) {
        if (headMap == null) {
            return null;
        }
        List> list = new ArrayList<>();
        for (String name : headMap.keySet()) {
            List head = new ArrayList<>();
            head.add(name);
            list.add(head);
        }
        return list;
    }

    public ExportDeal writeHandler(WriteHandler handler) {
        this.writeHandler = handler;
        return this;
    }

    private List> dataList(Map headMap, List datas) {
        if (headMap == null) {
            return null;
        }
        Long start = System.currentTimeMillis();
        List> list = new ArrayList<>();
        for (JSONObject json : datas) {
            List