using apache fileupload on GAE

问题:

I use Apache Commons FileUpload in a java server-side app that has a html form with fields :

1. A destination fied that will be filled with email address of the destination mailbox
2. A message text with a message of the sender
3. A < input type=file ... field for uploading a photo. I can receive uploaded file (as a stream) but how

This app I want to upload on GAE . I can receive uploaded file (as a stream , using org.apache.commons.fileupload.FileItemStream).

I want to receive too input textfields (i.e. 1) and 2)) - completed by the user of app)

I want to access these using org.apache.commons.fileupload.FileItem but I receive java.rmi.server.UID is a restricted class

回答1:

You should use the FileItemIterator of the Apache Commons FileUpload.

import org.apache.commons.fileupload.FileItemStream;
import org.apache.commons.fileupload.FileItemIterator;
import org.apache.commons.fileupload.servlet.ServletFileUpload;
import java.io.InputStream;
..
public void doPost(HttpServletRequest req, HttpServletResponse res)
      throws ServletException, IOException {
    try {
      ServletFileUpload upload = new ServletFileUpload();
      res.setContentType("text/plain");

      FileItemIterator iterator = upload.getItemIterator(req);
      while (iterator.hasNext()) {
        FileItemStream item = iterator.next();
        String name = item.getFieldName();
        InputStream stream = item.openStream();

        if (item.isFormField()) {
          //regular form field
          resp.getWriter().println(("Form:" + name + " : " + Streams.asString(stream));
        } else {
          //fileform field 
          resp.getWriter().println(("File:" +name + " : " + item.getName());
        }

      }
    } catch (Exception ex) {
      throw new ServletException(ex);
    }
}

回答2:

Take a look at this: Google App Engine and FileUpload

You can't write directly to the filesystem in GAE, but take a look at GAEVFS, which uses the datastore and memcache to emulate a filesystem.