HTTP compression - How to send precompressed files that exist in a EAR file?

Question

Is it possible to send pre-compressed files that are contained within an EARfile? More specifically, the jsp and js files within the WAR file. I am using Apache HTTP as the web server and although it is simple to turn on the deflate module and set it up to use a pre-compressed version of the files, I would like to apply this to files that are contained within an EAR file that is deployed to JBoss. The reason being that the content is quite static and compressing it on the fly each time is quite costly in terms of cpu time.

Quite frankly, I am not entirely familiar with how JBoss deploys these EAR files and 'serves' them. The gist of what I want to do is pre-compress the files contained inside the war so that when they are requested they are sent back to the client with gzip for Content-Encoding.

Answer 1

In theory, you could compress them before packging them in the EAR, and then serve them up with a custom controller which adds the http header to the response which tells the client they're compressed, but that seems like a lot of effort to go to.

When you say that on-the-fly compression is quite costly, have you actually measured it? Have you tried requesting a large number of uncompressed pages, measured the cpu usage, then tied it again with compressed pages? I think you may be over-estimating the impact. It uses quite low-intensity stream compression, designed to use little CPU resources.

You need to be very sure that you have a real performance problem before going to such lengths to mitigate it.

Answer 2

I don't frequent this site often and I seem to have left this thread hanging. Sorry about that. I did succeed in getting compression to my javascript and css files. What I did was I precompress them in the ant build process using the gzip. I then had to spoof the name to get rid of the gzip extension. So I had foo.js and compressed it into foo.js.gzip. I renamed this foo.js.gzip to foo.js and this is the file that gets packaged into the WAR file. So that handles the precompression part. To get this file served up properly, we just have to tell the browser that this file is compressed, via the content-encoding header of the http response. This was done via a output filter that is applied to files that matched the *.js extension (some Java/JBoss, WEB-INF/web.xml if it helps. I'm not too familiar with this so sorry guys).