How do I properly repackage the JRE installer in my installer?

Question

I've got a Java application that I'm writing an installer for. We're using the AdvancedInstaller program to create our installer (well, we're evaluating it currently, but will definitely purchase a license soon), and although it has special support for Java applications, it is geared more towards repackaging them as desktop-type apps, and our software is a series of Java services and other utilities which doesn't make sense to distribute in EXE-wrappers. The target audience for this software is very specific, and we know that our software will probably be automatically distributed on freshly-imaged Windows 2003 Server machines. So requiring Java as a prerequisite basically makes more work for some poor sysadmin, and I'd rather avoid that if at all possible by repackaging the JRE's installer inside of our own.

I discovered that if I tried to execute the JRE's installer as a pre-install step from my MSI, it complains that another installer is already running (mine, of course), so it bails out. When I try to add the JRE installer as a software prerequisite in the AdvancedInstaller project (as a bundled EXE, not a URL link), it never seems to actually get installed, despite me trying to force-install it.

What's the best way to repackage the JRE? I'm not really a Java guy, so I don't know too much about how other developers deal with this same problem, short of requiring their users to hunt out and install the JRE on their own. The ideal solution here would be for us to find a EXE installer which can be executed from inside of another MSI installer, or if it's possible, to just package all of the files inside of the JRE and then create the appropriate registry and environment variables. How should I go about doing this?

Answer 1

I have not idea if this is "the way" to do it, but confronted with a somewhat similar problem, we simply archive an installed JRE with the rest of our application files and make sure that all our start scripts don't use java ..., but rather ..\..\jre\bin\java ... or similar. The JRE is unpackaged as part of our installation process in a subdirectory of where we install and that's that.

Answer 2

I agree with bdumitriu's answer:

a simple zip of a jre is enough, unless you want to link that jre to:

• default java (meaning you must add java.exe of the unzipped jre to the path, before any other java path references)
• default java for some script (you could define JAVA_HOME as referencing your new unzipped jre, but that may have side effects on other script also using JAVA_HOME before that new JRE)
• file associations like .jnlp or .jar files (this requires some registry modifications)
• browser java plugin registration (which requires also registry modifications)

If the last two points do not interest you on the desktop concerned by this deplyment, a simple zip is enough.