controller层一个action控制多个excel文件下载if语句如何实现

假设有两个excel文件需要下载，可以在controller层的action方法中使用if语句实现多个文件下载的逻辑，示例代码如下：

@RequestMapping(value = "/download", method = RequestMethod.GET)
public void downloadExcel(HttpServletRequest request, HttpServletResponse response) throws IOException {
    String fileName1 = "file1.xlsx";
    String fileName2 = "file2.xlsx";
    String filePath1 = "/path/to/file1.xlsx";
    String filePath2 = "/path/to/file2.xlsx";
    
    if (StringUtils.isNotBlank(filePath1) && StringUtils.isNotBlank(fileName1)) {
        File file1 = new File(filePath1);
        if (file1.exists()) {
            response.setContentType("application/vnd.ms-excel");
            response.setHeader("Content-Disposition", "attachment;filename=" + URLEncoder.encode(fileName1, "UTF-8"));
            try (OutputStream outputStream = response.getOutputStream();
                 FileInputStream fileInputStream = new FileInputStream(file1)) {
                byte[] buffer = new byte[1024];
                int len;
                while ((len = fileInputStream.read(buffer)) > 0) {
                    outputStream.write(buffer, 0, len);
                }
                outputStream.flush();
            }
        }
    }
    
    if (StringUtils.isNotBlank(filePath2) && StringUtils.isNotBlank(fileName2)) {
        File file2 = new File(filePath2);
        if (file2.exists()) {
            response.setContentType("application/vnd.ms-excel");
            response.setHeader("Content-Disposition", "attachment;filename=" + URLEncoder.encode(fileName2, "UTF-8"));
            try (OutputStream outputStream = response.getOutputStream();
                 FileInputStream fileInputStream = new FileInputStream(file2)) {
                byte[] buffer = new byte[1024];
                int len;
                while ((len = fileInputStream.read(buffer)) > 0) {
                    outputStream.write(buffer, 0, len);
                }
                outputStream.flush();
            }
        }
    }
}

在上述代码中，首先定义了两个excel文件的文件名和文件路径，然后使用if语句判断文件是否存在，并根据文件存在与否来设置response的属性和输出流的内容。如果只有一个文件需要下载，可以直接去掉一个if语句