poi导出excel

public void export( HttpServletResponse response){

//方式一
//.xls
//HSSFWorkbook xls1 = new HSSFWorkbook();
//.xlsx
//XSSFWorkbook xls1= new XSSFWorkbook();

//方式2
//.xls
//Workbook xls1 = new HSSFWorkbook();
//.xlsx 以此为例往下
Workbook workbook = new XSSFWorkbook();

//创建sheet

Sheet sheet = workbook.createSheet("商品资料");

//创建行row:添加表头0行
Row row = sheet.createRow(0);

String[] titles = {"A","B","C","D"};//定义标题

Integer[] length={2000,1000,3000,4000};//定义列宽

Cell cell;//填充表头

for (int i = 0; i < titles.length; i++) {
    cell = row.createCell(i);
    cell.setCellValue(titles[i]);
    sheet.setColumnWidth(i, length[i] * 2);
}

Ｌist<Object> list=new ArrayList<>();//需要填入的数据

//创建单元格，并设置值
for (int i = 0; i < exportGoods.size(); i++) {
    int j = -1;
    row = sheet.createRow(i + 1);
    // 商品编码 国际条形码 商品名
    row.createCell(++j).setCellValue(list.get(i).getA());

　　row.createCell(++j).setCellValue(list.get(i).getB());

　　row.createCell(++j).setCellValue(list.get(i).getC());

　　row.createCell(++j).setCellValue(list.get(i).getD());

}

OutputStream outputStream = null;
try {
    response.setContentType("application/vnd.ms-excel");
    response.setHeader("Content-Disposition", "attachment;filename=" + URLEncoder.encode("XXXX.xlsx", "utf-8"));
    outputStream = response.getOutputStream();
    workbook.write(outputStream);
    outputStream.flush();
} catch (UnsupportedEncodingException e) {
    log.error("转换编码异常", e);
} catch (IOException e) {
    log.error("文件输出异常", e);
} finally {
    if (outputStream != null) {
        try {
            outputStream.close();
        } catch (IOException e) {
            log.error("OutputStream关闭异常", e);
        }
    }
}

}