Question

当我尝试上传数据以及附加的文件时，我有一个控制器发布方法。它工作正常。但是我想知道在没有附加文件时如何处理以及如何读取数据。这是我的控制器：

@RequestMapping(value="saveimage",method=RequestMethod.POST)
public ModelAndView saveimage( @RequestParam CommonsMultipartFile file,HttpSession session,HttpServletRequest request,HttpServletResponse response) throws Exception
{
DiskFileItemFactory factory = new DiskFileItemFactory();
factory.setSizeThreshold(THRESHOLD_SIZE);
factory.setRepository(new File(System.getProperty("java.io.tmpdir")));

ServletFileUpload upload = new ServletFileUpload(factory);
ServletContext context = session.getServletContext();

String uploadPath = context.getRealPath(UPLOAD_DIRECTORY);
System.out.println(uploadPath);    

System.out.println(file.getOriginalFilename());


byte[] bytes = file.getBytes();
BufferedOutputStream stream =new BufferedOutputStream(new FileOutputStream(new File(uploadPath + File.separator + file.getOriginalFilename())));
stream.write(bytes);
stream.flush();
stream.close();
EmpFileBean e=new EmpFileBean();
e.setFile(file.getOriginalFilename());
e.setTextdata(request.getParameter("textdata"));
     dao.saveImage(e);
     request.setAttribute("img_name", e.getFile());
return new ModelAndView("uploadform","filesuccess","File successfully saved!");
}

我的JSP看起来像：

  <form:form method="post" action="saveimage" attribute="EmpFileBean" 
  enctype="multipart/form-data">  
  <p><label for="image">Choose Image</label></p>  
  <p><input name="file" id="fileToUpload" type="file" path="file"/></p> 
  <p><label for="textdata">Enter User Name</label></p>  

  <p><input name="textdata" id="textdata" type="text" path="textdata"/></p>  
   <%
  if(request.getAttribute("img_name")!=null)
  {

  %>
  <img alt="" src="images/<%=request.getAttribute("img_name")%>">
  <%} %>

 <p><input type="submit" value="Upload"></p>  
  </form:form>

Answer 1

如果您使用@RequestParam进行多部分文件上传，那么如果该字段为空，则控制器不接受请求，说明某些错误消息

请求中不存在参数“file”，如：

但是，您可以将Model类用作@ModelAttribute，并在模型类中放置多部分文件对象及其setter，getter。也许这个类看起来像那样，

public class FileBean {

    private CommonsMultipartFile file;

    public CommonsMultipartFile getFile() {
        return file;
    }

    public void setFile(CommonsMultipartFile file) {
        this.file = file;
    }
}

来自控制器

@RequestMapping(value="saveimage",method=RequestMethod.POST)
public ModelAndView saveimage( @ModelAttribute FileBean file,HttpSession session,HttpServletRequest request,HttpServletResponse response) throws Exception{
----------------------- your controller code---------
}

让我知道状态。

如何将表单数据发送到CommonsMultipartFile Controller post方法而不附加文件？

1 个答案: