On 19/04/2010 17:06, Ken Bowen wrote: > Using Tomcat 6.0.18 (to be 6.0.26) and Google App Engine, for parallel > development (different db tech) > > Short form: I need to accept a file upload in a servlet, do some > computations on the upload, and then transition to a JSP with some data > resulting from the computations. I'm having some trouble with the > transition at the end. I need either to make the current code work or > find an > alternate way to achieve the goal. > > Long form. Here's the html for file upload (vanilla): > > <form name="csvUploadForm" action="csvfileupload" method="post" > enctype="multipart/form-data"> > File:<input type="file" name="csvfile2upload"><br></br> > <input type="submit" name="Submit" value="Upload CSV File" > onclick="uploadCSVFile();return false;"> > </form> > > Here's the servlet mapping for the receiving/processing servlet: > > <servlet-mapping> > <servlet-name>CSVFileUpload</servlet-name> > <url-pattern>/csvfileupload/*</url-pattern> > </servlet-mapping>
Why use a wildcard instead of an absolute/explicit path, in both the
action attribute and in the url-pattern?
> The CSVFileUpload servlet doPost method uses
> org.apache.commons.fileupload.servlet.ServletFileUpload;
> to accept and process the upload, and puts the resulting data into the
> db. If I don't care about duplicates or partial matches,
> this works fine; at the end of the servlet processing, I execute
> response.sendRedirect("/myStartPage.jsp");
> -- where response is the doPost's HttpServletResponse.
>
> Now I need to deal with partial matches between incoming data from the
> upload, and information already in the db. Specifically,
> I need to interact with the user to determine how to resolve the
> ambiguities. I /thought/ I could create a bean with the necessary computed
> info, use setAttribute to attach the bean to request (the doPost's
> HttpServletRequest), and then forward to a JSP with code like this:
>
> String nextJSP = "/nextPage.jsp";
> RequestDispatcher dispatcher =
> getServletContext().getRequestDispatcher(nextJSP);
> dispatcher.forward(request, response);
/myStartPage.jsp or /nextPage.jsp?
When does the redirect occur and when does the forward occur, it's not
entirely clear.
> Unfortunately, I'm running into the following errors showing in the log:
>
> WARNING: Nested in javax.servlet.ServletException:
> org.apache.commons.fileupload.FileUploadBase$InvalidContentTypeException: the
> request doesn't contain a multipart/form-data or multipart/mixed stream,
> content type header is null:
> org.apache.commons.fileupload.FileUploadBase$InvalidContentTypeException: the
> request doesn't contain a multipart/form-data or multipart/mixed stream,
> content type header is null
> at
> org.apache.commons.fileupload.FileUploadBase$FileItemIteratorImpl.<init>(FileUploadBase.java:885)
>
> at
> org.apache.commons.fileupload.FileUploadBase.getItemIterator(FileUploadBase.java:331)
>
> at
> org.apache.commons.fileupload.servlet.ServletFileUpload.getItemIterator(ServletFileUpload.java:148)
>
> at
> com.formrunner.servlets.CSVFileUploadServlet.doPost(CSVFileUploadServlet.java:53)
>
> at
> com.formrunner.servlets.CSVFileUploadServlet.doGet(CSVFileUploadServlet.java:29)
What's at CSVFileUploadServlet.java:53?
> The browser actually displays the nextPage.jsp page. However, if one
> then clicks any navigation button, you get a version of the warning
> above showing in the browser.
So you're catching the exception before executing the forward?
> I'm assuming that the CSVFileUpload servlet processing of the upload has
> stripped the request; hence the errors.
I'm not sure I concur, it seems a little unclear as to what is really
happening at this point.
p
> My goal is to get from the CSVFileUpload servlet to the nextPage.jsp
> with the "partialMatch" data in hand. In the normal use case, this
> will only be a couple of text lines. However, at the extreme it could
> be hundreds of lines of mismatches. I really don't care how I
> accomplish the transition to nextPage.jsp, so if there's a better way
> than what I'm attempting here, please let me know.
> {Anything written on the web would be great.} [I assume that I could
> store the "partialMatch" data in the db under some appropriate key, get
> to nextPage using response.sendRedirect, and then retrieve the info, but
> that seems like more of a hack than ought to be necessary here.]
>
> Thanks in advance,
> Ken
>
>
>
>
>
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