poi生成excel下载

一、springmvc入口

@RequestMapping(value="downloadExcel")
public void downloadExcel(HttpServletRequest request, HttpServletResponse response){
    OutputStream outputStream = null;
    FileOutputStream fileOutputStream = null;
    try {
        String fileName = "工作文档.xls";
        fileName = URLEncoder.encode(fileName, "UTF-8");
        response.reset();
        response.setContentType("application/vnd.ms-excel;charset=utf-8");
        response.setHeader("Content-Disposition", "attachment; filename=\"" + fileName + "\"");
        outputStream = response.getOutputStream();

        List<User> users = buildExcelContent();

        // 创建新的Excel 工作簿
        Workbook workbook = buildWorkbook(users);

        //写本地磁盘
        fileOutputStream = new FileOutputStream(new File("D:\\用户目录\\下载\\test.xls"));
        workbook.write(fileOutputStream);

        //下载
        workbook.write(outputStream);
    } catch (Exception e) {
        e.printStackTrace();
    } finally {
        try {
            if(outputStream != null){
                outputStream.close();
            }
            if(fileOutputStream != null){
                fileOutputStream.close();
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

二、构建内容

private List<User> buildExcelContent(){
    List<User> users = new ArrayList<>();
    User user = new User();
    user.setId(1);
    user.setUserName("张三");
    users.add(user);

    user = new User();
    user.setId(2);
    user.setUserName("李四");
    users.add(user);

    user = new User();
    user.setId(3);
    user.setUserName("王五");
    users.add(user);
    return users;
}

三、生成excel

private Workbook buildWorkbook(List<User> users){
    // 创建新的Excel 工作簿
    HSSFWorkbook workbook = new HSSFWorkbook();

    // 在Excel工作簿中建一工作表，其名为缺省值, 也可以指定Sheet名称
    HSSFSheet sheet = workbook.createSheet();
    HSSFSheet sheet = workbook.createSheet("SheetName");

    // 用于格式化单元格的数据
    HSSFDataFormat format = workbook.createDataFormat();

    // 创建新行(row),并将单元格(cell)放入其中. 行号从0开始计算.
    HSSFRow row = sheet.createRow((short) 1);

    // 设置字体
    HSSFFont font = workbook.createFont();
    font.setFontHeightInPoints((short) 20); //字体高度
    font.setColor(HSSFFont.COLOR_RED); //字体颜色
    font.setFontName("黑体"); //字体
    font.setBoldweight(HSSFFont.BOLDWEIGHT_BOLD); //宽度
    font.setItalic(true); //是否使用斜体
    //font.setStrikeout(true); //是否使用划线

    // 设置单元格类型
    HSSFCellStyle cellStyle = workbook.createCellStyle();
    cellStyle.setFont(font);
    cellStyle.setAlignment(HSSFCellStyle.ALIGN_CENTER); //水平布局：居中
    cellStyle.setWrapText(true);

    // 创建每行单元格
    HSSFCell cell = null;
    for(int i=0; i< users.size(); i++){
        row = sheet.createRow(i);

        cell = row.createCell(0);
        cell.setCellValue(users.get(i).getId());

        cell = row.createCell(1);
        cell.setCellValue(users.get(i).getUserName());
    }

    return workbook;
}

四、参考

https://www.cnblogs.com/azhqiang/p/4111197.html