CODEWITHSUNDEEP
javatomcatservletsgwtfile-upload
Dennis Ich
Dennis Ich

Reputation: 3775

ServletFileUpload, GWT not breaking at to big files

I got a GWT application and we need to upload files but i want to limit the size. So currently i have this: 

ServletFileUpload.isMultipartContent(request);
FileItemFactory factory = new DiskFileItemFactory();
ServletFileUpload upload = new ServletFileUpload(theFactory);
upload.setFileSizeMax(<2mb>);
upload.setSizeMax(<2mb>);

try {
    final List<FileItem> items = upload.parseRequest(request);
    for (FileItem fileItem : items) {
        <do file stuff>
    }
}
catch (FileUploadException e) {
    <break and return error>
}

When i upload a 300mb+ file in dev mode as soon as it hits the for loop it breaks and says the file is to big in the exception. This happens a second after I hit the upload button.

When the application is deployed on a tomcat it waits till the file is fully uploaded instead of breaking before and rejecting the file.

I know there is a tomcat parameter but the sizes of files I accept for upload is very different for the different servlets and i want to set this individually for the servlets and not the biggest value which can be much more than the mostly accepted values.

Upvotes: 0

Views: 117

Answers (1)

alexp
alexp

Reputation: 797

You can add a ChangeHandler to your upload button in GWT, and call a native method from it passing the button's element in:

    private native boolean isFileSizeValid(Element inputFile)/*-{
       var fileToUpdate = inputFile.files[0];
       return fileToUpdate.size < 200...0; // pick the right number
    }-*/;

This will work fine for single file (if 'multiple' is disabled on the input element). If you allow for uploading multiple files you can iterate through all items of files[] array and do the math.

This approach will help you to perform all the validation client-side, but needs FileAPI support from the client browser. http://caniuse.com/#feat=fileapi

Sorry, if you were looking for backend validation only.

Upvotes: 1

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