SBT (Scala Build Tool) can be used with Maven to leverage Maven's infrastructure. The SBT Maven plugin allows integrating SBT projects with Maven. SBT was inspired by Maven's project modeling but aims to have behavior defined in Scala rather than XML. SBT projects can define a build.sbt file to configure projects, tasks, and dependencies similarly to how Maven uses POM files.

1. SBT
Tomer Ben David

2. Contents
Brief overview of SBT
SBT maven plugin for integration with MAVEN!
So we can reuse Maven Infrastructure

3. SBT - scala build tool
More teams are joining scala coding
Spark development is mostly done in scala
SBT got much inspired by maven
Modelling is good in maven, behaviour is somewhat harder (xml)
SBT can join forces with maven model in maven behaviour in scala
With richness comes complexity

4. You can run SBT with no code
Main object
run sbt run
it compile and runs
expected maven style directory structure
src/main/scala or java

5. define a project
build.sbt in root folder
lazy val root = (project in file(“.”)).
settings(
name := “hello”,
version := “1.0

6. project dir
can contain scala files
ie
Build.scala

7. Interactive mode
sbt console

8. Continuous build
~ compile
will compile upon changes

9. History commands
!
!!

10. Build definition
each project associated with immutable map key value pairs
keys have a method named :=
This method returns back Settings
build does not change map
it create settings which is a set of transformations on key value pairs

11. Three flavour of keys
SettingKey
TaskKey - computed each time potentially with side effects
compile, package they can have return value or no return value
InputKey

12. Built in keys
sbt.Keys._

13. Create example taskKey
lazy val hello = taskKey[Unit](“An example key”)

14. Assign value - operation to a task
task key
lazy val hello = taskKey[Unit](“an example task key”)
task value (operation)
lazy val root = (project in file(“.”)).
settings(
hello := { println(“hello”) }
)

15. “compile” is a task key

16. dependencies
val derby = “org.apache.derby” % “derby” % “10.4.1.3”
later on: libraryDependencies += derby
+= appends to the keys old value rather than replace

17. Scopes
in truth a key can have different value in different scopes
a key can have different value for each project
compile key can have different values for source and test source if you want to
compile them differently
packageOptions can have different values when packging class files or source
code
There is a single value for a given scoped key

18. Setting key in scopes
name in (Compile, packageBin) := “hello”

19. Set the source directory for compile
sourceDirectory in Compile += new File(“source”)

20. Refer to key’s value
organization := name.value
name := baseDirectory.value.getName

21. Examples
name := "99-scala-solutions"
version := "0.1"
description := "99 scala solutions"
startYear := Some(2015)
licenses += "Apache-2.0" -> url("http://www.apache.org/licenses/LICENSE-
2.0.html")

22. Examples
val commonScalacOptions = Seq(
"-encoding", "UTF-8" // Specify character encoding used by source files
, "-target:jvm-1.8" // Target platform for object files
, "-Xexperimental" // Enable experimental extensions
, "-Xfuture" // Turn on future language features
, "-Ybackend:GenBCode" // Choice of bytecode emitter
)
scalacOptions ++= commonScalacOptions ++ Seq(
"-deprecation" // Emit warning and location for usages of deprecated APIs
, "-feature" // Emit warning and location for usages of features that should be imported explicitly
, "-g:vars"

23. Examples

24. Examples
settings(
startServer := {
println(“starting”)
Thread.sleep(500)
then from sbt commandline
sbt> startServer

25. SBT Maven Plugin