SpringBoot获取resources下的文件

例如下载/resources/excel/template.xlsx

@GetMapping("/download")
    public void downloadFile(HttpServletRequest request,
                             HttpServletResponse response) {
          
   
        String fullFileName = "excel/template.xlsx";
        ExcelUtils.exportLocalExcel(request, response, fullFileName);
    }

ExcelUtils.java

public class ExcelUtils {
          
   

    /**
     * 导出本地Excel
     *
     * @param httpRequest  请求信息
     * @param httpResponse 响应信息
     * @param pathFileName 带路径的文件名字
     */
    public static void exportLocalExcel(HttpServletRequest httpRequest, HttpServletResponse httpResponse, String pathFileName) throws Exception {
          
   
        String[] split = pathFileName.split("/");
        ClassPathResource classPathResource = new ClassPathResource(pathFileName);
        InputStream fis = classPathResource.getInputStream();
        httpResponse.setContentType("application/application/vnd.openxmlformats-officedocument.spreadsheetml.sheet;charset=utf-8");
        String rawFileName = split[split.length - 1];
        String fileName = FileNameUtil.getPrefix(rawFileName);
        String suffix = FileNameUtil.getSuffix(rawFileName);
        httpResponse.setHeader("Content-Disposition", "attachment;filename=" + getFileName(fileName, httpRequest) + "." + suffix);
        ServletOutputStream outputStream = httpResponse.getOutputStream();
        if (fis.available() != 0) {
          
   
            httpResponse.setStatus(200);
        }
        IOUtils.copy(fis, outputStream);
        fis.close();
        outputStream.flush();
        outputStream.close();
    }

    /**
     * 处理文件名字编码
     *
     * @param fileName 文件名字
     * @param request  请求信息
     * @return 编码后文件名
     * @throws Exception 异常信息
     */
    private static String getFileName(String fileName, HttpServletRequest request) throws Exception {
          
   
        String ua = request.getHeader("User-Agent").toLowerCase();
        if (ua.contains("macintosh") && !ua.contains("chrome")) {
          
   
            //浏览器: safari
            return new String(fileName.getBytes(), "ISO8859-1");
        }
        //默认utf-8
        return URLEncoder.encode(fileName, StandardCharsets.UTF_8.name());
    }
}