Question

I’m using Spring and Hibernate. I’m uploading images using commons-fileupload-1.2.2 as follows.

String itemName = null;
String files = null;        
String itemStatus="true";
Random rand=new Random();
Long randNumber=Math.abs(rand.nextLong());

Map<String, String> parameters=new HashMap<String, String>();

if (ServletFileUpload.isMultipartContent(request))
{
    ServletFileUpload upload = new ServletFileUpload(new DiskFileItemFactory());
    List<FileItem> items = null;

    try
    {
         items = upload.parseRequest(request);
    }
    catch (FileUploadException e)
    {
         mv.addObject("msg", e.getMessage());
         mv.addObject("status", "-1");
    }

    for(FileItem item:items)
    {                
        if (!item.isFormField()&&!item.getString().equals(""))
        {
             itemName = item.getName();
             parameters.put(item.getFieldName(), item.getName());
             itemName = itemName.substring(itemName.lastIndexOf(File.separatorChar) + 1, itemName.length());

             itemName=randNumber+itemName;
             files = files + " " + itemName;

             ServletContext sc=request.getSession().getServletContext();
             File savedFile = new File(sc.getRealPath("images") , itemName);
             item.write(savedFile);

             File medium = new File(sc.getRealPath("images"+File.separatorChar+"medium") , itemName);
             item.write(medium);
        }
    }
}

Where itemName is the name of the image file after parsing the request (enctype="multipart/form-data").

The image is first being saved in the images folder and then in the images/medium folder. It’s not working causing FileNotFoundException but when I save only one file (commenting out one of them) either this

File savedFile = new File(sc.getRealPath("images") , itemName);
item.write(savedFile);

or this

File medium = new File(sc.getRealPath("images"+File.separatorChar+"medium") , itemName);
item.write(medium);

it works. Why doesn’t it work to save both the files in separate folders at once?

Answer 1

I have not used apache commons-fileupload, but the apidoc for the function FileItem#write(File file) says, writing the same item twice may not work.

This method is not guaranteed to succeed if called more than once for
the same item. This allows a particular implementation to use, for
example, file renaming, where possible, rather than copying all of the
underlying data, thus gaining a significant performance benefit.

JavaDoc for DiskFileItem class says,

This method is only guaranteed to work once, the first time it is
invoked for a particular item. This is because, in the event that the
method renames a temporary file, that file will no longer be available
to copy or rename again at a later time.

You might also want to check out this JIRA:
DiskFileItem Jira Issue

References: FileItem JavaDoc, DiskFileItem JavaDoc