java生成zip文件，zip文件分两种：一种是包含文件夹、一种是不包含文件夹

生成zip文件的方式

        ZipOutputStream zipOutputStream = new ZipOutputStream(response.getOutputStream());
            
        // 文件夹名称
        String folder = "download/";
           
        ZipEntry ze = new ZipEntry(folder);
        zipOutputStream.putNextEntry(ze);
            
        ze = new ZipEntry(folder + "test.xlsx");
        zipOutputStream.putNextEntry(ze);

        // 读取文件内容并写入ZIP文件中
        FileInputStream fis = new FileInputStream(new File(excelName));
        byte[] buffer = new byte[1024];
        int len;
        while ((len = fis.read(buffer)) > 0) {
            zipOutputStream.write(buffer, 0, len);
        }
        fis.close();

        zipOutputStream.closeEntry();
        zipOutputStream.close();