Direct file download vs reading a file back as download

Question

Is there any difference between creating a direct link to a file on a server, and doing something like reading the file from a location and setting the content type header then streaming back the data.

I'm curious because I have a webserver that i'm using to download apps to a blackberry, if i create a file and have a direct link to that file it works, but if i stream it back using an webpage it doesn't work. The phone gets the file but it doesn't work.

Things to note:

• urls are the same in both cases ie (http://somesite.com/download/file.jad)
• in a browser using fiddler the downloads/header are exactly the same byte for byte

So why would the phone prefer a file that's actually a direct link vs one that is a controller streaming the data back when the data transmitted and the url are identical?

Answer 1

I discovered a fix for this problem though I'm still not sure what causes it. I have been delivering the link to the phone through the sms/email gateway. When the phone gets the sms and I select the link for download it asks if i want to get the jad i hit yes and it shows up and drop out. I put the exact same link on another page as an html link and sent an sms pointing to that page. The web site throws an error... So I copied and pasted the link into the phones browser and the page shows up just fine, I click the jad download link on the page and now the jad works fine.

So i'm thinking two things either there is some sort of security mechanism that prevents direct links in sms(but this has worked for other files) Or the way the phone gets the url is different.

I ran some tests and noticed something else, on a page that accepts an id value (http://site.com/download/145) where 145 is an id for a file, if you go to that link in a phone browser it works fine and you download the file. If you send it in an sms the server errors out saying that the id is expected to be a float and it received a string. So why is it that when the phone links directly from sms the url parameters are strings but when used in a browser the actually get parsed as a float?

Sorry for the long winded explanation but it's a strange issue.

Answer 2

The .JAD file is just the first part of the download - there are also the .COD files associated with it (referenced in the JAD). Did you ensure that your "streaming" method is sending back the COD file correctly and with the correct MIME types?