Get started with Gradle and Kotlin/JVM

This tutorial demonstrates how to use IntelliJ IDEA and Gradle to create a JVM console application.

To get started, first download and install the latest version of IntelliJ IDEA.

Create a project

In IntelliJ IDEA, select File | New | Project.
In the panel on the left, select Kotlin.
Name the new project and change its location, if necessary.
Select the Create Git repository checkbox to place the new project under version control. You will be able to do it later at any time.
Select the Gradle build system.
From the JDK list, select the JDK that you want to use in your project.
- If the JDK is installed on your computer, but not defined in the IDE, select Add JDK and specify the path to the JDK home directory.
- If you don't have the necessary JDK on your computer, select Download JDK.
Select the Kotlin DSL for Gradle.
Select the Add sample code checkbox to create a file with a sample "Hello World!" application.
You can also enable the Generate code with onboarding tips option to add some additional useful comments to your sample code.
Click Create.

You have successfully created a project with Gradle!

Specify a Gradle version for your project

You can explicitly specify a Gradle version for your project under the Advanced Settings section, either by using the Gradle Wrapper or a local installation of Gradle:

Gradle Wrapper:
1. From the Gradle distribution list, select Wrapper.
2. Disable the Auto-select checkbox.
3. From the Gradle version list, select your Gradle version.
Local installation:
1. From the Gradle distribution list, select Local installation.
2. For Gradle location, specify the path of your local Gradle version.

Explore the build script

Open the build.gradle.kts file. This is the Gradle Kotlin build script, which contains Kotlin-related artifacts and other parts required for the application:

plugins {
    kotlin("jvm") version "2.1.20" // Kotlin version to use
}

group = "org.example" // A company name, for example, `org.jetbrains`
version = "1.0-SNAPSHOT" // Version to assign to the built artifact

repositories { // Sources of dependencies. See 1️⃣
    mavenCentral() // Maven Central Repository. See 2️⃣
}

dependencies { // All the libraries you want to use. See 3️⃣
    // Copy dependencies' names after you find them in a repository
    testImplementation(kotlin("test")) // The Kotlin test library
}

tasks.test { // See 4️⃣
    useJUnitPlatform() // JUnitPlatform for tests. See 5️⃣
}

1️⃣ Lean more about sources of dependencies.
2️⃣ The Maven Central Repository. It can also be Google's Maven repository or your company's private repository.
3️⃣ Learn more about declaring dependencies.
4️⃣ Learn more about tasks.
5️⃣ JUnitPlatform for tests.

As you can see, there are a few Kotlin-specific artifacts added to the Gradle build file:

In the plugins {} block, there is the kotlin("jvm") artifact. This plugin defines the version of Kotlin to be used in the project.
In the dependencies {} block, there is testImplementation(kotlin("test")). Learn more about setting dependencies on test libraries.

Run the application

Open the Gradle window by selecting View | Tool Windows | Gradle:
Execute the build Gradle task in Tasks\build\. In the Build window, BUILD SUCCESSFUL appears. It means that Gradle built the application successfully.
In src/main/kotlin, open the Main.kt file:
- src directory contains Kotlin source files and resources.
- Main.kt file contains sample code that will print Hello World!.
Run the application by clicking the green Run icon in the gutter and select Run 'MainKt'.

You can see the result in the Run tool window:

Congratulations! You have just run your first Kotlin application.

What's next?

Learn more about:

Last modified: 25 September 2024