public static ExcelWriterBuilder write(OutputStream outputStream, Class head) {
        ExcelWriterBuilder excelWriterBuilder = new ExcelWriterBuilder();
        excelWriterBuilder.file(outputStream);
        if (head != null) {
            excelWriterBuilder.head(head);
        }
        return excelWriterBuilder;
    }
Build excel the write

@param outputStream Output stream to write
@param head         Annotate the class for configuration information.
@return Excel writer builder
fastexcel-core/src/main/java/cn/idev/excel/FastExcelFactory.java