java 导出批量excel（分多个sheet）

HSSFWorkbook wb = new HSSFWorkbook();
    OutputStream output = response.getOutputStream();
    List list = this.findActualReturnDetial(params);
    int totle = list.size();// 获取List集合的size
    int mus = 65535;// ：excel表格一个工作表可以存储65536条）
    int avg = totle / mus;
    for (int i = 0; i < avg + 1; i++) {
      HSSFSheet sheet = wb.createSheet("实际还款明细" + (i + 1));
      HSSFRow row = sheet.createRow(0);
      // 第一行标题
      String[] head = new String[]{"机构合同编号", "拍拍贷列表号", "借款人姓名", "贷款本金", "贷款利率", "贷款期数", "还款方式",
          "放款日", "到期日",
          "当期期数", "当期应还款日", "当期应还本金", "当期应还利息", "当期应还逾期利息", "当期实际还款日", "当期实还本金", "当期实还利息",
          "当期实还逾期利息",
          "剩余总本金", "当期还款状态", "逾期天数"};
      int headInt = 0;
      for (String title : head) {
        row.createCell(headInt++).setCellValue(title);
      }
      int num = i * mus;
      int index = 0;
      int rowInt = 1;
      for (int m = num; m < list.size(); m++) {
        if (index == mus) {// 判断index == mus的时候跳出当前for循环
          break;
        }
        ActualReturnDetial actualReturnDetial = list.get(m);
        // 每列对应的字段
        row = sheet.createRow(rowInt++); // 创建行
        row.createCell(0).setCellValue(actualReturnDetial.getLoanid());
        row.createCell(1).setCellValue(actualReturnDetial.getListingid());
        row.createCell(2).setCellValue(actualReturnDetial.getCmstrRealName());
        row.createCell(3).setCellValue(actualReturnDetial.getAmount());
        row.createCell(4).setCellValue(actualReturnDetial.getRate());
        row.createCell(5).setCellValue(actualReturnDetial.getMonths());
        row.createCell(6).setCellValue(actualReturnDetial.getRepType());
        row.createCell(7).setCellValue(actualReturnDetial.getAuditingDate());
        row.createCell(8).setCellValue(actualReturnDetial.getEndDate());
        row.createCell(9).setCellValue(actualReturnDetial.getOrderid());
        row.createCell(10).setCellValue(actualReturnDetial.getDuedate());
        row.createCell(11).setCellValue(actualReturnDetial.getPrincipal());
        row.createCell(12).setCellValue(actualReturnDetial.getInterest());
        row.createCell(13).setCellValue(actualReturnDetial.getDun());
        row.createCell(14).setCellValue(actualReturnDetial.getPaymentdate());
        row.createCell(15).setCellValue(actualReturnDetial.getRepPrincipal());
        row.createCell(16).setCellValue(actualReturnDetial.getRepInterest());
        row.createCell(17).setCellValue(actualReturnDetial.getRepDun());
        row.createCell(18).setCellValue(actualReturnDetial.getResiduePrincipal());
        row.createCell(19).setCellValue(actualReturnDetial.getRepStatus());
        row.createCell(20).setCellValue(actualReturnDetial.getCurrentdefaultdays());

        index++;
      }
    }
    response.setHeader("Content-Disposition", "attachment;filename=actualreturndetial.xls");
    response.setContentType("application/ms-excel");
    wb.write(output);
    output.close();

java导出批量数据分多个sheet。

注意事项：

1. 执行row.createCell(1).setCellValue(actualReturnDetial.getListingid());当setCellValue的为Integer值时注意

由于会转为setCellValue(double value) 当Integer为空时会报错空指针错误。

为了避免空指针错误，把值尽量转为string再setCellValue();

2. 由于机器io限制，导出过多数据会导致机器io爆满，当导出大量数据时，最后先把导出的数据放到文件再导出文件。

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