CODEWITHSUNDEEP
javaeclipsejar
svk
svk

Reputation: 101

jar file with all the dependeny libraries unpacked

I am trying to build my application jar (non executable jar) with all it's dependenices jar files also to unpack.

Simply to explain my issue, in eclipse, to export runnable/executable jar, there is an option "Extract required libraries into generated Jar"

Please help me the same option for non-runnable jar also.

Thanks

Upvotes: 1

Views: 1599

Answers (2)

pron
pron

Reputation: 1733

Use Capsule. It does everything you want including set JVM configuration right in the manifest.

With capsule you have the option of packing all of your JARs and native libs right into the capsule JAR, or you can specify your Maven dependencies in the Manifest, and let them be downloaded the first time the capsule is launched.

Upvotes: 1

user1915201
user1915201

Reputation: 103

No there isn't.

Just as background: Packaging dependencies within a JAR file (sometimes called a fat jar or app jar) is not a native Java mechanism but is grafted on using custom ClassLoaders or start scripts packaged in the JAR.

If you create a runnable JAR file with Eclipse it uses a wrapper to run your application which can read the packaged libraries. You can see this if you open the exported JAR file and look at it's Manifest:

Manifest-Version: 1.0
Rsrc-Class-Path: ./ [removed]
Class-Path: .
Rsrc-Main-Class: com.example.Test
Main-Class: org.eclipse.jdt.internal.jarinjarloader.JarRsrcLoader

The JarRsrcLoader sits between your applications Main-Class and the Java Runtime and can then load the packaged dependencies before executing your code. In a library there is no such hook that Eclipse can hook into since the loading is done by someone using your library and you can't control the loading process.

There are mechanisms to combine JAR files into a single one by unpacking the dependencies and then repackaging them into your JAR. Look here for example: How to combine two Jar files

Note though that by repackaging a 3rd party JAR you might run into issues with signed classes or conflicting Metadata.

If you want to publish a library and/or manage dependencies properly I recommend looking into build systems like Maven (http://maven.apache.org/) or Gradle (http://www.gradle.org/). I personally much prefer Gradle.

Edit: This project seems promising: https://github.com/puniverse/capsule

Upvotes: 1

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