使用 java servlet 和 apache poi 库下载 xls 文件

Question

I am trying to download xls file by fetching data from mysql database table and java servlet and apache poi library. I am creating fetching data, creating xls file and flushing it into ServletOutputStream.

But file is downloading in different format which is not a proper xls file. I found code is correct, response header is correct.

SQL query is working fine.

Whats wrong? Code is here...

HSSFWorkbook workbook = new HSSFWorkbook();
HSSFSheet firstSheet = workbook.createSheet("GSTR1");

java.sql.ResultSet rs = conx.createStatement().executeQuery(sql);
java.sql.ResultSetMetaData ds = rs.getMetaData();

                HSSFRow rowA1 = firstSheet.createRow(0);
                int c1 = 1;
                while(c1 < ds.getColumnCount())
                {
                    HSSFCell cellA = rowA1.createCell(c1);
                    Object obj = ds.getColumnLabel(c1);
                    if(obj != null)
                    {
                        String data = obj.toString();
                        cellA.setCellValue(data);
                    }
                    else
                    {
                        cellA.setCellValue(""); 
                    }
                    c1++;
                }
                
                int r = 1;
                while(rs.next())
                {
                    HSSFRow rowA = firstSheet.createRow(r);
                    int c = 1;
                    while(c < ds.getColumnCount())
                    {
                        HSSFCell cellA = rowA.createCell(c);
                        Object obj = rs.getString(c);
                        if(obj != null)
                        {
                            String data = obj.toString();
                            cellA.setCellValue(data);
                        }
                        else
                        {
                            cellA.setCellValue(""); 
                        }
                        c++;
                    }
                    r++;
                }

byte[] byteStream = workbook.getBytes();
response.setContentLength(byteStream.length);

servletOutputStream = response.getOutputStream();
servletOutputStream.write(byteStream);

response.addHeader("Content-disposition", "attachment;filename=file.xls");
response.setContentType("application/vnd.ms-excel");
servletOutputStream.flush();
servletOutputStream.close();

Answer 1

I had the same issue. My workaround was to use org.apache.commons.io.IOUtils.write(content, response.getOutputStream());