sbt-onejar is a simple-build-tool plugin for building a single executable JAR containing all your code and dependencies as nested JARs.
Currently One-JAR version 0.9.7 is used. This is included with the plugin, and need not be separately downloaded.
Requires SBT 0.12.x, or 0.13.x
Users of SBT 0.7.x are directed to the v0.2.
Currently, you need to include the setting
exportJars := true if you have a multi-project build. (Example)
Depend on the plugin by editing
addSbtPlugin("org.scala-sbt.plugins" % "sbt-onejar" % "0.8")
Include the settings from
You can configure
mainClass in oneJar := Some("com.acme.Woozler"). It defaults to
mainClass in run in Compile.
one-jar task to generate, erm, one JAR. Run it with
java -jar <jarname>.
What's in the JAR?
As an example of the structure, here is the contents of
scalaz-example_2.8.1-5.1-SNAPSHOT-onejar.jar, a package built from the Scalaz examples module.
. |-- META-INF | `-- MANIFEST.MF |-- OneJar.class |-- boot-manifest.mf |-- com | `-- simontuffs | `-- onejar | |-- Boot$1.class | |-- Boot$2.class | |-- Boot$3.class | |-- Boot.class | |-- Handler$1.class | |-- Handler.class | |-- IProperties.class | |-- JarClassLoader$1.class | |-- JarClassLoader$2.class | |-- JarClassLoader$ByteCode.class | |-- JarClassLoader$FileURLFactory$1.class | |-- JarClassLoader$FileURLFactory.class | |-- JarClassLoader$IURLFactory.class | |-- JarClassLoader$OneJarURLFactory.class | |-- JarClassLoader.class | |-- OneJarFile$1.class | |-- OneJarFile$2.class | |-- OneJarFile.class | `-- OneJarURLConnection.class |-- doc | `-- one-jar-license.txt |-- lib | |-- scala-library.jar | |-- scalaz-core_2.8.1-5.1-SNAPSHOT.jar | |-- scalaz-example_2.8.1-5.1-SNAPSHOT.jar | |-- scalaz-geo_2.8.1-5.1-SNAPSHOT.jar | |-- scalaz-http_2.8.1-5.1-SNAPSHOT.jar | `-- servlet-api-2.5.jar |-- main `-- scalaz-example_2.8.1-5.1-SNAPSHOT.jar
How does it compare to XXX?
There are other ways to package your application. I based this plugin on Coda Hale's sbt-assembly which builds an über-JAR, directly containing all classes and resources merged together. This approach must be used carefully when there are resources with the same name across multiple JARs.
Kris Nuttycombe's sbt-proguard-plugin also creates an über-JAR, with the possibility to obfuscate and shrink. This is popular for targeting Android. Proguard is a powerful tool, and it takes some effort to configure it correctly.
One-JAR employs some classloader magic to sidestep the über-JAR limitations. It does support classpath scanning, as used in Spring and Hibernate, although there seems to be a performance penalty for this. But if your application, or its libraries, also relies on classloader trickery, you might run into some problems. Caveat Emptor.
Looking for something else? One of these might suit: WebStart, Exe4J, jsmooth, izpack.
Please report bugs and feature requests to the GitHub issue tracker. Bugs with small sample project will get the most attention. Forks and Pull Requests are also welcome.
Problems with One-JAR itself should be reported on it's Issue Tracker
Copyright (c) 2011-2011 Jason Zaugg
Published under The MIT License, see LICENSE
The One-JAR License is reproduced below. This plugin is not endorsed in anyway by One-JAR.
Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:
Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.
Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.
Neither the name of P. Simon Tuffs, nor the names of any contributors, nor the name One-JAR may be used to endorse or promote products derived from this software without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.