L
laredotornado
Hi,
I'm using Java 6. Is it possible to include a JAR file within a JAR
file? Thanks, - Dave
I'm using Java 6. Is it possible to include a JAR file within a JAR
file? Thanks, - Dave
K
Knute Johnson
Not practically. Why would you want to?
A
Arne Vajhøj
Not out of the box.
You can special classloaders that can do such magic, but the
practical solution is to place all the jar files in the file
system.
And actually it do have some advantages because it allow
to update one or more independently of the rest.
Arne
M
markspace
http://one-jar.sourceforge.net/
But this should be a last resort. Check out Java Web Start. Also, you
can deliver several Jar files in a zip file and then unpack them, and
have a class path set to the required Jars. Both of these options
should be explored before resorting to the OneJAR code above.
L
Lew
Actually, you can put a JAR file inside a JAR file, just like you can put a
ZIP file inside a ZIP file. It won't do you much good, but you can do it.
Everyone assumes the OP wants to use the inner JAR file as a classpath
element, but he didn't actually say that. All he asked was if it's possible
to include a JAR file inside another, and of course that's a big resounding "Yes".
As Knute Johnson asked,
It is likely that the OP will be disappointed with the usefulness of doing
what he asked.
A
Arne Vajhøj
I assumed that he wanted to execute the code inside the jars
inside the jar.
Arne
J
Joshua Cranmer
Well, a JAR file is a file, so you can put it in a JAR file. On the
other hand, using a JAR file within another one is a bit of a different
matter....
K
Knute Johnson
I did too.
L
Lew
Knute said:
That makes you part of "everyone". But Knute, you asked him anyway why he
would want to, so at least you tested your assumption (assuming he answers
your question).
D
Donkey Hottie
Indeed. A WAR file is a JAR file, and usually contains JAR files which
can be used. An EAR file is JAR file, and usually contains WAR files and
JAR files... And they are all used!
However, some JEE containers extract all the contents of EAR or WAR
before use.
L
Lew
Donkey said:
I don't know of any that don't.
A
Arne Vajhøj
Me neither.
But it would be doable. All that is needed is that the
server comes with a classloader capable of doing it. And
that JSP pages were compiled in memory not to disk.
But the app server vendors can probably not see any reason
to do so.
Arne
L
Lew
A big reason not to do so is that it would defeat the role of "deployer" in
their ability to tweak deployment descriptors and property files.
A
Arne Vajhøj
Why?
Those should be tweaked before deployment.
Tweaking the files after the app server has expanded
the ear/war is not good.
Arne
M
Mike Schilling
Lew said:
Unpacking wars is optional behavior in Tomcat.
R
Roedy Green
you could using WinZip but it would not be useful. Unpack the jar and
add its element if you want java to be able to use the contents.
--
Roedy Green Canadian Mind Products
http://mindprod.com
To err is human, but to really foul things up requires a computer.
~ Farmer's Almanac
It is breathtaking how a misplaced comma in a computer program can
shred megabytes of data in seconds.
D
Donkey Hottie
I remember having been with WebLogic, and we had to manually extract our
WAR in that. It supports extracted and unextracted WAR files, but you
have to manually extract if that is a requirement for the application.
That was WebLogic 8.1.
L
Lew
Donkey said:
I use WebLogic 10.x and later and they don't do that. You can just deploy an
"unextracted" WAR. It creates a working (extracted) copy in its temporary
directories.
Are you absolutely certain 8.1 didn't do that?
D
Donkey Hottie
Nope. It's just how I remember. We tried to access "some files in the
war" but could not in WebLogic, in Tomcat t worked. But when we deployed
as an extracted folder, it worked.
Dunno. I was a newbie with J2EE back then (that it is pretty much
different now, I'm a guru
)
L
Lew
Nope. It's just how I remember. We tried to access "some files in the
war" but could not in WebLogic, in Tomcat t worked. But when we deployed
as an extracted folder, it worked.
Dunno. I was a newbie with J2EE back then (that it is pretty much
different now, I'm a guru
I'm a little puzzled myself, and not near the particular WebLogic environment
just now anyway. I think it might have to do with the fact that the unpacked
stuff is in a temporary directory and not really somewhere comfortable.
Doesn't the Java EE spec require containers to accept either a WAR or
directory-based deployment? Maybe not and I'm too lazy right now to look it
up. I don't think there's anything in there that requires a container to
unpack a WAR, but I figure it's the easiest way to deploy a WAR, just as
unpacking a ZIP-based application is the easiest way to deploy it.