Jars inside one jar?

[Karthik Guru]

hi all,
I know that this can be done.
I want the user to set the classpath to the enclosing jar file.
The other jar files s'd be automatically be available.
What s'd i specify in the manifest file?
Encloser.jar
-- a.jar (specifies the main in it's manifest)
-- b.jar
Now i want the user to set the classpath to Encloser.jar and say
java -jar Encloser.jar
==> This s'd result int he main class inside a.jar to execute.
How can this be done. Can someone supply me the manifest of Encloser.jar
thanks in advance,
karthik.

[Cindy Glass]

A jar file is just a zipped file that maintains the subdirectory structure.
Inside Encloser.jar you have a set of subdirectories. Some of them contain other jar files that are just a futher breakdown of subdirectories. In the end the Encloser.jar has to have a manifest file that names the .class file in a.jar to kick off, with the complete subdirectory location spelled out - starting from the location that Encloser.jar is in.
And get rid of the Manifest in a.jar. You will confuse the rest of us.

[Cindy Glass]

You know, now that I think about it, I have never really SEEN a jar file inside another jar file - and I have surely never tested to see if it works.
Tell us how it works out.

[Karthik Guru]

i c'dnt get that to work :-(.
So i have a final.jar which in turn has some jars inside it + directory structures / files etc.
So i had to ask the client to extract the enclosing jar file.
One more thing i found out while working with executable jar files :
I posted it in the ranch but no one has has confirmed it as yet in the forum.
the class-path setting is immaterial when using executable jar files. IF the executable jar refers to other jars, then we normally have a
Class-Path attribute in the manifest.
So depending upon this attribute setting the other jars are searched.
Class-Path: another1.jar another2.jar
another1.jar and another2.jar will be searched only in the same directory as the executable jar file. Explicit classpath settign does'nt help.
if we say
(in manifest),
Class-Path: .\folder\another1.jar .\folder\another2.jar
then it w'd search in folder named "folder" relative to the location of the executable jar file.
I c'd'nt digest it early on that i c'd ship an application that did'nt need a classpath setting!
Just make sure that the dependent jar files are in the same folder as executable jar file or in a specific subfolder relative to the executable jar.
Am still waiting for responses though. My application works just fine.
karthik.

Originally posted by Cindy Glass:
You know, now that I think about it, I have never really SEEN a jar file inside another jar file - and I have surely never tested to see if it works.
Tell us how it works out.

[Peter den Haan]

Originally posted by Cindy Glass:
You know, now that I think about it, I have never really SEEN a jar file inside another jar file

Any application server that will run war files without unpacking them (which ones do anyway?) runs jars within jars.
- Peter