java 同步导出excel数据

1. 依赖导入

<!-- https://mvnrepository.com/artifact/org.apache.poi/poi -->
        <dependency>
            <groupId>org.apache.poi</groupId>
            <artifactId>poi</artifactId>
            <version>4.1.2</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.apache.poi/poi-ooxml -->
        <dependency>
            <groupId>org.apache.poi</groupId>
            <artifactId>poi-ooxml</artifactId>
            <version>4.1.2</version>
        </dependency>

2. 生成excel

 Workbook wb = null;
        if (result.size() < 1000) {
            wb = new XSSFWorkbook();
        } else {
            wb = new SXSSFWorkbook();
        }
        //设置表格的格式--居中
        CellStyle cs = wb.createCellStyle();
        cs.setAlignment(HorizontalAlignment.CENTER);
        //创建工作表
         Sheet sheet = wb.createSheet("测试");
        //设置列宽，有多少列，写多少列，0，1，2，3，4，5..........
         sheet.setColumnWidth(0,20 * 256);

         //创建行-表头行
        Row row = sheet.createRow(0);

        //创建格,有多少格创建多少格，0，1，2，3，4，5..........
        Cell cell = row.createCell(0);
        cell.setCellValue("tt");
        cell.setCellStyle(cs);

        //写入数据
          for (Info info: result) {
             row = sheet.createRow(result.indexOf(info) + 1);
             
             //有多少个创建多少格子，0，1，2，3，4，5..........
             row.createCell(0).setCellValue(info.getName()!=null?info.getName():"");
         }
       //提供下载
       response(request, response,wb,  "文件名称",date);

3. 返回文件

注意：这个不能用异步请求，不然会报错，前端需要注意下。

private void response(HttpServletRequest request, HttpServletResponse response, Workbook wb, String name, String date) throws IOException {
OutputStream outputStream =null;
        try {
            //设置Http响应头告诉浏览器下载这个附件
            outputStream = response.getOutputStream();
            String userAgent = request.getHeader("USER-AGENT");
            String fileName11;
            String fileName = name + date + ".xlsx";
            if(StringUtils.contains(userAgent, "Firefox") || StringUtils.contains(userAgent, "firefox")){
                //火狐浏览器
                fileName11 = new String(fileName.getBytes(), "ISO8859-1");
            }else{
                //其他浏览器
                fileName11 = URLEncoder.encode(fileName,"UTF-8");
            }
            String headStr = "attachment; filename="" + fileName11 + """;
            response.setContentType("application/0000000000000000000000000000");
            response.setCharacterEncoding("UTF-8");
            response.addHeader("Content-Disposition", headStr);
            wb.write(outputStream);
            outputStream.flush();
        } catch (Exception ex) {
            ex.printStackTrace();
        }finally {
            if (null != outputStream) {
                try {
                    outputStream.close();
                } catch (IOException e) {
                         ex.printStackTrace();
                }
            }
        }
}