Easiest way to merge a release into one JAR file
Is there a tool or script which easily merges a bunch of JAR files into one JAR file? A bonus would be to easily set the main-file manifest and make it executable.
The concrete case is a Java restructured text tool. I would like to run it with something like:
java -jar rst.jar
As far as I can tell, it has no dependencies which indicates that it shouldn't be an easy single-file tool, but the downloaded ZIP file contains a lot of libraries.
0 11-30-07 10:01 jrst-0.8.1/
922 11-30-07 09:53 jrst-0.8.1/jrst.bat
898 11-30-07 09:53 jrst-0.8.1/jrst.sh
2675 11-30-07 09:42 jrst-0.8.1/readmeEN.txt
108821 11-30-07 09:59 jrst-0.8.1/jrst-0.8.1.jar
2675 11-30-07 09:42 jrst-0.8.1/readme.txt
0 11-30-07 10:01 jrst-0.8.1/lib/
81508 11-30-07 09:49 jrst-0.8.1/lib/batik-util-1.6-1.jar
2450757 11-30-07 09:49 jrst-0.8.1/lib/icu4j-2.6.1.jar
559366 11-30-07 09:49 jrst-0.8.1/lib/commons-collections-3.1.jar
83613 11-30-07 09:49 jrst-0.8.1/lib/commons-io-1.3.1.jar
207723 11-30-07 09:49 jrst-0.8.1/lib/commons-lang-2.1.jar
52915 11-30-07 09:49 jrst-0.8.1/lib/commons-logging-1.1.jar
260172 11-30-07 09:49 jrst-0.8.1/lib/commons-primitives-1.0.jar
313898 11-30-07 09:49 jrst-0.8.1/lib/dom4j-1.6.1.jar
1994150 11-30-07 09:49 jrst-0.8.1/lib/fop-0.93-jdk15.jar
55147 11-30-07 09:49 jrst-0.8.1/lib/activation-1.0.2.jar
355030 11-30-07 09:49 jrst-0.8.1/lib/mail-1.3.3.jar
77977 11-30-07 09:49 jrst-0.8.1/lib/servlet-api-2.3.jar
226915 11-30-07 09:49 jrst-0.8.1/lib/jaxen-1.1.1.jar
153253 11-30-07 09:49 jrst-0.8.1/lib/jdom-1.0.jar
50789 11-30-07 09:49 jrst-0.8.1/lib/jewelcli-0.41.jar
324952 11-30-07 09:49 jrst-0.8.1/lib/looks-1.2.2.jar
121070 11-30-07 09:49 jrst-0.8.1/lib/junit-3.8.1.jar
358085 11-30-07 09:49 jrst-0.8.1/lib/log4j-1.2.12.jar
72150 11-30-07 09:49 jrst-0.8.1/lib/logkit-1.0.1.jar
342897 11-30-07 09:49 jrst-0.8.1/lib/lutinwidget-0.9.jar
2160934 11-30-07 09:49 jrst-0.8.1/lib/docbook-xsl-nwalsh-1.71.1.jar
301249 11-30-07 09:49 jrst-0.8.1/lib/xmlgraphics-commons-1.1.jar
68610 11-30-07 09:49 jrst-0.8.1/lib/sdoc-0.5.0-beta.jar
3149655 11-30-07 09:49 jrst-0.8.1/lib/xalan-2.6.0.jar
1010675 11-30-07 09:49 jrst-0.8.1/lib/xercesImpl-2.6.2.jar
194205 11-30-07 09:49 jrst-0.8.1/lib/xml-apis-1.3.02.jar
78440 11-30-07 09:49 jrst-0.8.1/lib/xmlParserAPIs-2.0.2.jar
86249 11-30-07 09:49 jrst-0.8.1/lib/xmlunit-1.1.jar
108874 11-30-07 09:49 jrst-0.8.1/lib/xom-1.0.jar
63966 11-30-07 09:49 jrst-0.8.1/lib/avalon-framework-4.1.3.jar
138228 11-30-07 09:49 jrst-0.8.1/lib/batik-gui-util-1.6-1.jar
216394 11-30-07 09:49 jrst-0.8.1/lib/l2fprod-common-0.1.jar
121689 11-30-07 09:49 jrst-0.8.1/lib/lutinutil-0.26.jar
76687 11-30-07 09:49 jrst-0.8.1/lib/batik-ext-1.6-1.jar
124724 11-30-07 09:49 jrst-0.8.1/lib/xmlParserAPIs-2.6.2.jar
As you can see, it is somewhat desirable to not need to do this manually.
So far I've only tried AutoJar and ProGuard, both of which were fairly easy to get running. It appears that there's some issue with the constant pool in the JAR files.
Apparently jrst is slightly broken, so I'll make a go of fixing it. The Maven pom.xml file was apparently broken too, so I'll have to fix that before fixing jrst ... I feel like a bug-magnet :-)
Update: I never got around to fixing this application, but I checked out Eclipse's "Runnable JAR export wizard" which is based on a fat JAR. I found this very easy to use for deploying my own code.
Some of the other excellent suggestions might be better for builds in a non-Eclipse environment, oss probably should make a nice build using Ant. (Maven, so far has just given me pain, but others love it.)
Answer
Ant's zipfileset does the job
<jar id="files" jarfile="all.jar">
<zipfileset src="first.jar" includes="**/*.java **/*.class"/>
<zipfileset src="second.jar" includes="**/*.java **/*.class"/>
</jar>