Basic SBT Usages

1. SBT doesn’t include a command to create a new project
A shell script to build a Scala SBT project directory structure
http://alvinalexander.com/sbtmkdirs

#!/bin/sh
mkdir -p src/{main,test}/{java,resources,scala}
mkdir lib project target

# create an initial build.sbt file
echo 'name := "MyProject"

version := "1.0"

scalaVersion := "2.10.0"' > build.sbt

2.
From the root directory of the project, you can compile the project:
$ sbt compile

Run the project:
$ sbt run

Package the project as a jar file"
$ sbt package

Run all test class in the test folder:
$ sbt test

Run a single test case
$ set test-only Classname

Generate the files Eclipse needs
$ sbt eclipse

Generate the files IntelliJ needs
$ sbt gen-idea

3. Dependencies Management

If you have JAR files (unmanaged dependencies) that you want to use in your project, simply copy them to the lib folder in the root directory of your project, and SBT will find them automatically.

The groupID, artifactID, revision, and configuration strings correspond to what Ivy requires to retrieve the module you want.

libraryDependencies += groupID % artifactID % revision % configuration

To add multiple managed dependencies to your project, define them as a Seq in your build.sbt file:

libraryDependencies ++= Seq(
  "net.sourceforge.htmlcleaner" % "htmlcleaner" % "2.4",
  "org.scalatest" % "scalatest_2.10" % "1.9.1" % "test",
  "org.foobar" %% "foobar" % "1.8"
)

The %% method adds your project’s Scala version to the end of the artifact name.

4. Use an SBT plug-in sbt-assembly to build a single, complete JAR file that can be executed with a simple java command. This requires that Java is installed on client systems.

(1) Create file plugins.sbt in the "project" folder:

resolvers += Resolver.url("artifactory",
url("http://scalasbt.artifactoryonline.com/scalasbt/sbt-plugin-releases"))(Resolver.ivyStylePatterns)

addSbtPlugin("com.eed3si9n" % "sbt-assembly" % "0.11.2") 

Note: the folder structure is: MyProject/project/plugins.sbt 

(2) Add these two lines to the top of your build.sbt file

import AssemblyKeys._

assemblySettings

(3) $ sbt assembly

5. You have multiple main methods in objects in your project, and you want to specify which main method should be run when you type sbt run

// set the main class for packaging the main jar
mainClass in (Compile, packageBin) := Some("com.alvinalexander.testproject.Foo")

sbtmkdirs.sh

#!/bin/bash

#------------------------------------------------------------------------------
# Name:    sbtmkdirs
# Version: 1.2
# Purpose: Create an SBT project directory structure with a few simple options.
# Author:  Alvin Alexander, http://alvinalexander.com
# License: Creative Commons Attribution-ShareAlike 2.5 Generic
#          http://creativecommons.org/licenses/by-sa/2.5/
#------------------------------------------------------------------------------
declare -r TRUE=0
declare -r FALSE=1

# takes a string and returns true if it seems to represent "yes"
function isYes() {
  local x=$1
  [ $x = "y" ] && echo $TRUE; return
  [ $x = "Y" ] && echo $TRUE; return
  [ $x = "yes" ] && echo $TRUE; return
echo $FALSE
}

echo "This script creates an SBT project directory beneath the current directory."

while [ $TRUE ]; do

echo ""
  read -p "Directory/Project Name (MyFirstProject): " directoryName
  directoryName=${directoryName:-MyFirstProject}

  read -p "Create .gitignore File? (Y/n): " createGitignore
  createGitignore=${createGitignore:-y}

  read -p "Create README.md File? (Y/n): " createReadme
  createReadme=${createReadme:-y}

  echo ""
  echo "-----------------------------------------------"
  echo "Directory/Project Name: $directoryName"
  echo "Create .gitignore File?: $createGitignore"
  echo "Create README.md File?: $createReadme"
  echo "-----------------------------------------------"
  read -p "Create Project? (Y/n): " createProject
  createProject=${createProject:-y}
  [ "$(isYes $createProject)" = "$TRUE" ] && break

done

mkdir -p ${directoryName}/src/{main,test}/{java,resources,scala,assembly}
mkdir ${directoryName}/lib ${directoryName}/target
#mkdir ${directoryName}/project 
# optional
mkdir -p ${directoryName}/src/main/config
#mkdir -p ${directoryName}/src/{main,test}/{filters,assembly}
#mkdir -p ${directoryName}/src/site

#---------------------------------
# create an initial build.sbt file
#---------------------------------
echo "name := \"$directoryName\"

organization := \"com.paytmlabs\"

version := \"1.0\"

scalaVersion := \"2.11.6\"

val sparkVersion = \"1.2.0\"

libraryDependencies <<= scalaVersion {
  scala_version => Seq(
    // Spark and Spark Streaming
    \"org.apache.spark\" %% \"spark-core\" % sparkVersion,
    \"org.apache.spark\" %% \"spark-mllib\" % sparkVersion,
    \"org.apache.spark\" %% \"spark-streaming\" % sparkVersion,
    \"org.apache.spark\" %% \"spark-streaming-kafka\" % sparkVersion,
    // Kafka
    \"org.apache.kafka\" %% \"kafka\" % \"0.8.1.1\",
    // for serialization of case class
    \"com.novus\" %% \"salat\" % \"1.9.8\",
    // Joda dates for Scala
    \"com.github.nscala-time\" %% \"nscala-time\" % \"1.2.0\"
  )
}

resolvers += \"typesafe repo\" at \"http://repo.typesafe.com/typesafe/releases/\"

scalacOptions += \"-deprecation\"

" > ${directoryName}/build.sbt

#------------------------------
# create .gitignore, if desired
#------------------------------
if [ "$(isYes $createGitignore)" = "$TRUE" ]; then
echo "bin/
project/
target/
.cache
.classpath
.project
.settings" > ${directoryName}/.gitignore
fi

#-----------------------------
# create README.me, if desired
#-----------------------------
if [ "$(isYes $createReadme)" = "$TRUE" ]; then
touch ${directoryName}/README.md
fi

echo ""
echo "Project is successfully created!"

Reference:

http://www.scala-sbt.org/0.13/tutorial/Library-Dependencies.html

http://alvinalexander.com/sbtmkdirs