java将List<Map<String,Object>>导出Excel

遇到了个需要导出Excel的需求，经过百度查到方法在此记录一下：

public static void  createExcel(List<Map<String, Object>> mapList, String filename, String title, HttpServletResponse response) {
        //获取数据源的 key, 用于获取列数及设置标题
        Map<String, Object> map = mapList.get(0);
        Set<String> stringSet = map.keySet();
        ArrayList<String> headList = new ArrayList<>(stringSet);
        //定义一个新的工作簿
        XSSFWorkbook wb = new XSSFWorkbook();
        //创建一个Sheet页
        XSSFSheet sheet = wb.createSheet(title);
        //设置行高
        sheet.setDefaultRowHeight((short) (2 * 256));
        //为有数据的每列设置列宽
        for (int i = 0; i < headList.size(); i++) {
            sheet.setColumnWidth(i, 8000);
        }
        //设置单元格字体样式
        XSSFFont font = wb.createFont();
        font.setFontName("等线");
        font.setFontHeightInPoints((short) 16);
        //在sheet里创建第一行，并设置单元格内容为 title (标题)
        XSSFRow titleRow = sheet.createRow(0);
        XSSFCell titleCell = titleRow.createCell(0);
        titleCell.setCellValue(title);
        //合并单元格CellRangeAddress构造参数依次表示起始行，截至行，起始列， 截至列
        sheet.addMergedRegion(new CellRangeAddress(0, 0, 0, headList.size() - 1));
        // 创建单元格文字居中样式并设置标题单元格居中
        XSSFCellStyle cellStyle = wb.createCellStyle();
        cellStyle.setAlignment(HorizontalAlignment.CENTER);//水平居中
        cellStyle.setVerticalAlignment(VerticalAlignment.CENTER);//垂直居中
        titleCell.setCellStyle(cellStyle);

        //获得表格第二行
        XSSFRow row = sheet.createRow(1);
        //根据数据源信息给第二行每一列设置标题
        for (int i = 0; i < headList.size(); i++) {
            XSSFCell cell = row.createCell(i);
            cell.setCellValue(headList.get(i));
        }
        XSSFRow rows;
        XSSFCell cells;
        //循环拿到的数据给所有行每一列设置对应的值
        for (int i = 0; i < mapList.size(); i++) {
            //在这个sheet页里创建一行
            rows = sheet.createRow(i + 2);
            //给该行数据赋值
            for (int j = 0; j < headList.size(); j++) {
                String value;
                if (mapList.get(i).get(headList.get(j)) !=null){
                    value = mapList.get(i).get(headList.get(j)).toString();
                }else {
                    value = "";
                }
                cells = rows.createCell(j);
                cells.setCellValue(value);
            }
        }
        try {
            response.setContentType("application/vnd.ms-excel");
            filename = URLEncoder.encode(filename, "UTF-8");
            response.setHeader("Content-Disposition", "attachment;filename="
                    .concat(filename));
            OutputStream out = response.getOutputStream();
            wb.write(out);
            wb.close();
            out.close();;
        } catch (IOException e) {
            e.printStackTrace();
        }
    }