Problems uploading blobs onto App Engine

Question

Hi i'm trying to upload some mp3s as blobs using the Complete Sample App code provided in the App Engine tutorial here and i'm getting the following error `HTTP ERROR 404

Problem accessing /_ah/upload/ag5jb2xsZWN0aXZlZ3dhcHIbCxIVX19CbG9iVXBsb2FkU2Vzc2lvbl9fGHQM. Reason:

No upload session: ag5jb2xsZWN0aXZlZ3dhcHIbCxIVX19CbG9iVXBsb2FkU2Vzc2lvbl9fGHQM`

Anyone have any ideas why i'm getting this? Tried running locally and even tried deploying the App and still having issues!

Answer 1

Do not press the back botton and try to upload file.Use to hit the url in browser every time.

Answer 2

For each upload of file to the blob, the blob url is unique. For the first time, when you upload a file, you might be creating one blob url, using

blobstoreService.createUploadUrl("/yourServerURL");

Now, when you try to upload next file, you are clicking back button and you are trying to use the same blob session which you have created for the first file. That is the reason, you are facing the "No upload Session" error.

The solution could be, you can create a new blob url when you click the back button. Do some work around to create a new blob url upon clicking the back button.

Hope this helps.

Thanks.