Even though the servlet does not understand if-modified-since header that we set, our code still checks the last-modified and content-length before doing actual download. If those matches, we won't download again. And the servlet does pass back correct last-modified and content-length.
I tried again and I still cannot reproduce the problem. I will contact the submitter for more information.
customer testcase shows 2 problems:
1. multiple GET requests to the same JNLP file.
2. subsequent launches will cause download window pop up with no progress bar.
For 1, need more investigation to see why we make multiple GET requests to the same jnlp file.
For 2, The reason why you see the download dialog is because we didn't see the 304 respond, and is entering the download code. But before we do actual download, we check the last-modified and content length against the cached entry. If it matches, it won't start the actual download. That's why there is no progress bar, and if you dig into the cache, you will see the cache entry is not modified.
I agree we should update the sample servlet to handle the if-modified-since header. With that, you should probably not see the download dialog pop up anymore.