write (ExcelUtils)

Writes an Excel file to the HTTP response with column width adaptation, dropdown sheets, and Long-to-String conversion to avoid precision loss, then sets download headers.

    public static <T> void write(HttpServletResponse response, String filename, String sheetName,
                                 Class<T> head, List<T> data) throws IOException {
        // 输出 Excel
        FastExcelFactory.write(response.getOutputStream(), head)
                .autoCloseStream(false) // 不要自动关闭，交给 Servlet 自己处理
                .registerWriteHandler(new ColumnWidthMatchStyleStrategy()) // 基于 column 长度，自动适配。最大 255 宽度
                .registerWriteHandler(new SelectSheetWriteHandler(head)) // 基于固定 sheet 实现下拉框
                .registerConverter(new LongStringConverter()) // 避免 Long 类型丢失精度
                .sheet(sheetName).doWrite(data);
        // 设置 header 和 contentType。写在最后的原因是，避免报错时，响应 contentType 已经被修改了
        response.addHeader("Content-Disposition", "attachment;filena

... (truncated -- full source via MCP)