使用EasyExcel生成表格并且返回File对象

通过此方法,可以导出表格并且存入File对象中进行其他的操作,这里通过File来进行异步存储到文件服务器,用于下载中心

 public static <T> File exportReturnToFile(List<T> data, Class<T> clazz, String fileName) {
        File file = null;
        //名称拆分前后缀
        //1.判断文件名是否有扩展
        try {
            if (StringUtils.isBlank(fileName)) {
                file = File.createTempFile(fileName, "");
            } else {
                String[] parts = fileName.split("\\.");
                String extension = "." + parts[parts.length - 1];
                String name = fileName.substring(0, fileName.length() - extension.length() - 1);
                file = File.createTempFile(name, extension);
            }
        } catch (IOException e) {
            log.error("文件生成失败,文件名异常.异常信息:{}", e.getMessage());
            throw new CustomException("文件生成失败,文件名异常");
        }

        HorizontalCellStyleStrategy horizontalCellStyleStrategy = defaultStylePolicyPolicy();

        //导出
        EasyExcel.write(file, clazz)
                .registerWriteHandler(new LongestMatchColumnWidthStyleStrategy())
                .registerWriteHandler(horizontalCellStyleStrategy)
                .sheet()
                .doWrite(data);


        return file;
    }
    /**
     * 默认样式策略策略
     *
     * @return
     */
    private static HorizontalCellStyleStrategy defaultStylePolicyPolicy() {
        // 头的策略
        WriteCellStyle headWriteCellStyle = new WriteCellStyle();
        // 背景设置为浅蓝色
        headWriteCellStyle.setFillForegroundColor(IndexedColors.PALE_BLUE.getIndex());
        //设置水平对齐方式
        headWriteCellStyle.setHorizontalAlignment(HorizontalAlignment.CENTER);
        //设置字体为微软雅黑
        WriteFont headWriteFont = new WriteFont();
        headWriteFont.setFontName("宋体");
        headWriteCellStyle.setWriteFont(headWriteFont);

        // 内容的策略
        WriteCellStyle contentWriteCellStyle = new WriteCellStyle();
        contentWriteCellStyle.setHorizontalAlignment(HorizontalAlignment.CENTER);
        //设置字体为微软雅黑
        WriteFont contentWriteFont = new WriteFont();
        contentWriteFont.setFontName("宋体");
        contentWriteCellStyle.setWriteFont(contentWriteFont);

        // 这个策略是 头是头的样式 内容是内容的样式
        return new HorizontalCellStyleStrategy(headWriteCellStyle, contentWriteCellStyle);
    }