Sbt
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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.
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task value (operation)
lazy val root = (project in file(“.”)).
settings(
hello := { println(“hello”) }
)](https://image.slidesharecdn.com/sbt-151230124740/85/Sbt-14-320.jpg)
Sbt
- 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
- 8. Continuous build ~ compile will compile upon changes
- 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
- 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