Java中Spring Controller如何下载文件呢?

实现思路：
    借助向HttpServletResponse对象向客户端发送字节流
	即可实现数据下载

@RequestMapping(value = "/files/{file_name}", method = RequestMethod.GET)
public void downloadFile(
    @PathVariable("file_name") String fileName, 
    HttpServletResponse response) {
    try {
      //获取实际文件流
      InputStream is = ...;
      //将文件流复制到输出流中
      org.apache.commons.io.IOUtils.copy(is, response.getOutputStream());
      response.flushBuffer();
    } catch (IOException ex) { 
      throw new RuntimeException("IOError writing file to output stream");
    }
}