apache POI - 获取生成的excel文件的大小 [英] apache POI - get size of generated excel file

问题描述

我正在使用 Apache POI 在我的spring mvc应用程序中生成excel文件。这是我的春季行动：

I'm using Apache POI for generating excel file in my spring mvc application. here is my spring action:

 @RequestMapping(value = "/excel", method = RequestMethod.POST)
public void companyExcelExport(@RequestParam String filter, @RequestParam String colNames, HttpServletResponse response) throws IOException{
    XSSFWorkbook workbook = new XSSFWorkbook();
    //code for generate excel file
    //....

    response.setContentType("application/vnd.openxmlformats-officedocument.spreadsheetml.sheet");
    response.setHeader("Content-Disposition", "attachment; filename=test.xlsx");
    workbook.write(response.getOutputStream());

    response.setHeader("Content-Length", "" + /* How can i access workbook size here*/);
}

我用 XSSFWorkbook 因为我需要生成Excel 2007格式。但我的问题是 XSSFWorkbook 没有 getBytes 或 getSize 方法。如何计算生成的xlsx文件的大小？

I used XSSFWorkbook because i need to generate Excel 2007 format. but my problem is XSSFWorkbook does not have getBytes or getSize method. How can i calculate size of generated xlsx file?

编辑：我使用 ByteArrayOutputStream 就像这里：

I used ByteArrayOutputStream like here:

ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
workbook.write(response.getOutputStream()); 
workbook.write(byteArrayOutputStream);
response.setHeader("Content-Length", "" + byteArrayOutputStream.size());

推荐答案

正如@JB Nizet所说：在写作之前设置标题回复。

As @JB Nizet said : set the Header before writing the response .

所以你应该做的是：

ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
workbook.write(byteArrayOutputStream);
response.setHeader("Content-Length", "" + byteArrayOutputStream.size());
workbook.write(response.getOutputStream()); 

请参阅此答案此处，因为它描述了如何将ByteArrayOutputStream与HSSFWorkbook一起使用。

and please refer to this answer here , as it describes how to use the ByteArrayOutputStream with the HSSFWorkbook .

希望有所帮助。

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