创建使用Apache POI和servlet多个工作表 [英] Creating multiple sheets using Apache poi and servlets

问题描述

当我创建使用Apache POI和servlet多个工作表。这是创建表，但不能写入文件中的数据。我试图写第1000记录sheet1和接下来的1000至低于code到Sheet2，但不工作

When i am creating multiple sheets using Apache poi and servlets. It is creating the sheet but not writing the data to file. I am trying to write the first 1000 records to sheet1 and next 1000 to sheet2 through below code, but not working

private void writeDataToExcelFile(String string,
        ArrayList<ArrayList<String>> excelData, OutputStream outputStream) {
    HSSFWorkbook myWorkBook = new HSSFWorkbook();
    String sheetName = "";
    sheetName = "Document-" + 0;
    HSSFSheet mySheet = myWorkBook.createSheet();
    HSSFRow myRow = null;
    HSSFCell myCell = null;
    for (int rowNum = 0; rowNum < excelData.size(); rowNum++) {
        ArrayList<String> rowData = excelData.get(rowNum);
        if(rowNum>0 && rowNum%1000 == 0)
        {
            sheetName = "Document-" + (rowNum/1000);
            mySheet = myWorkBook.createSheet();
        }
        myRow = mySheet.createRow(rowNum);
        for (int cellNum = 0; cellNum < rowData.size(); cellNum++) {
            myCell = myRow.createCell(cellNum);
            myCell.setCellValue(rowData.get(cellNum));
        }
    }
    System.out.println("Last row:" + mySheet.getLastRowNum());
    System.out.println("Row number:" + mySheet.rowIterator().next().getRowNum());
    try {
        myWorkBook.write(outputStream);
    } catch (Exception e) {
        e.printStackTrace();
    } finally {
        try {
            outputStream.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

我logic.Please做要紧的帮助有什么不对。
谢谢

What is wrong with my logic.Please do the needful help. Thanks

推荐答案

当您完成数据集的循环，你是想在1000行，当你开始新的工作表拆分，开始新的工作表，这是很好的，但是，您所创建的下一行是1001行（外循环索引变量）

When you loop through the dataset, you are wanting to split at row 1000 to start a new sheet, which is fine, however when you start the new sheet, the next row you create is row 1001 (the outer loop index variable)

myRow = mySheet.createRow(rowNum);

要得到你想要的效果，改变循环是这样的：

To get the effect you wish, change the loop to be something like this:

int currentRow = 0;
for (int rowNum = 0; rowNum < excelData.size(); rowNum++) 
{
  ArrayList<String> rowData = excelData.get(rowNum);

  if(currentRow == 1000)
  {
    sheetName = "Document-" + (rowNum/1000);
    mySheet = myWorkBook.createSheet();
    currentRow = 0;
  }
  myRow = mySheet.createRow(currentRow);
  for (int cellNum = 0; cellNum < rowData.size(); cellNum++) 
  {
    myCell = myRow.createCell(cellNum);
    myCell.setCellValue(rowData.get(cellNum));
  }

  currentRow++;
}

我没有这个选项编译，所以我不知道这是否会马上工作，但它应该指向你在正确的方向。

I haven't compiled this, so I don't know if it'll work right away, but it should point you in the right direction.

心连心

修改结果
想到这里进一步，你可以从制作1号线更改原始应用程序获得同样的效果（虽然失去了清晰的一点点）：

Edit
Thinking about this further, you could get the same effect from making a 1 line change to the original application (albeit losing a little bit of clarity):

myRow = mySheet.createRow(rowNum%1000);

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