Packaging and Deploying Scala Applications

Question

What is the simplest way to package a Scala application for use on a desktop PC? I'm guessing that would be in the form of a jar file.

At the moment I'm using SBT to compile and run programs

I'd be interested in solutions for machines that have Scala installed (and the library in their classpath), as well as those that only have Java.

Solution 1

The simplest (and the most consistent) way to package a Scala application, is packaging into a JAR (like you do with normal Java applications). As long as JAR consists of standard compiled Java classes, you may run "Scala" JAR, even if you don't have Scala runtime at the box (all you need is a Java Runtime and scala-lang.jar on the classpath). You may specify the main class (gateway to functionalities of your application) in the manifast

Main-Class: mypackage.MyClass

so that you'll be able to call it only passing a JAR name to java.exe.

java -jar myjar.jar

You may specify the main class in SBT project definition.

Solution 2

http://www.scala-sbt.org/sbt-native-packager/index.html

The plugin allows you to package in a variety of formats(zip, tar, deb, dmg, msi, etc) and in different archtypes.

Comments

[se681268]

I managed to get this far using the "package" command in SBT. I don't suppose you know how to include scala-library.jar in the resulting jar file?

[Vasil Remeniuk]

Put the JAR into src/main/resources, and add it to the classpath -->> override val manifestClassPath = Some("scala-library.jar")

[Vasil Remeniuk]

However, even if you package scala-library.jar into your app jar, it won't be bootstrapped by the classloader. In order to make the manifest update I mentioned above work, you will have to put scala-library.jar to the same folder with your jar.

[mlg]

@SimonMorgan: coming half a year late, but may be useful for others: you may want to try this plugin for including dependencies in the jar: github.com/sbt/sbt-assembly