How to update file in Jar using API

Question

Hi,
I have a jar file (actually a war file), and I need to update the properties in one of the files before I deploy it.
I have been able to open it, get the correct JarEntry, load the properties, update the properties, but am struggling to figure out how to save it back to the Jar file?
Any ideas?
cheers,
David

Answer 1

So why isn't your build process just creating thecorrect contents of that properties file
before including it in the war it builds, in thefirst place?
Because we deploy it in many customers. They will
obviously have different ip addresses eg for the
database machine.
Therefore we have certain properties that are
customer-specific we need to update in the war before
we deploy it.
cheers,
DavidI wasn't implying that your build process is only run one time. The build process can be run each time you build for each deployment. So do you mean you only want to deliver one generic WAR to each customer, and you want this change of properties to happen on the customer side somehow? What code are you going to run on that side to change it - not code in your web app because at that point it's too late - you've already loaded the web app and its files, which this/these property files are a part of. Sounds like you need a "build process" to bundle up the app for each unique target.
Alternatively you could investigate adding or altering the manifest file in the WAR (or EAR) file to reference an additional standalone, or loose, directory (outside the WAR/EAR structure) and put your property files there. Then that directory would become part of your app's classpath just like it were in your WAR/EAR, and you could update that file independently.