build.gradle

// Build script for project.
buildscript {
  // Use the newest version of Kotlin available.
  ext.kotlin_version = '1.1.4-3'

  // Read from Maven's central repository.
  repositories {
    mavenCentral()
  }

  // Use the Gradle for Kotlin plugin for simplified access.
  dependencies {
    classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
  }
}

// The buildscript classpath dependency allows us to specify Kotlin.
apply plugin: 'kotlin'

// Dependencies used in our project: JRE 8 and JUnit are by default.
dependencies {
  testCompile 'junit:junit:4.12'
  compile "org.jetbrains.kotlin:kotlin-stdlib-jre8:$kotlin_version"
}

// Non-standard project structure: Specify source and test directories.
sourceSets {
  main.kotlin.srcDirs += 'src'
  test.kotlin.srcDirs += 'test'
}

// Again, read from Maven's central repository.
repositories {
  mavenCentral()
}

// These two options allow us to compile Kotlin code to JVM 8 bytecode.
compileKotlin {
  kotlinOptions {
    jvmTarget = "1.8"
  }
}
compileTestKotlin {
  kotlinOptions {
    jvmTarget = "1.8"
  }
}