后端以文件流的形式返回本地资源

//文件地址
String path = "PDFpath";

File file = new File(PDFpath);

//读取生成的PDF文件
InputStream inputStream;
OutputStream outputStream;
响应设置 重制输出流

try {
   if (file.exists()){
       inputStream = new FileInputStream(file);
       outputStream = new BufferedOutputStream(response.getOutputStream());
       byte[] bytes = new byte[1024];
       int len;
       while ((len = inputStream.read(bytes)) != -1){
           response.getOutputStream().write(bytes,0,len);
       }
       outputStream.flush();
       outputStream.close();
       inputStream.close();
   }
    } catch (FileNotFoundException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
}

在接口测试中可以使用postman的Send And Download进行测试。