Create Kotlin Project with Gradle

Kotlin has become a popular language for many developers due to its modern features and seamless integration with existing Java code. Gradle, as a build tool, supports Kotlin and provides a robust platform for building Kotlin projects. This guide will walk you through setting up a Gradle project for Kotlin.

Step 1: Install Gradle

Ensure that Gradle is installed on your system.

On Windows

1. Download Gradle: Download the latest Gradle distribution from Gradle's official website.
2. Extract the Download: Extract the downloaded ZIP file to a directory of your choice.
3. Set Environment Variables:
   • Open the System Properties window (Win + Pause).
   • Click on "Advanced system settings" and then "Environment Variables".
   • Add a new GRADLE_HOME variable pointing to the extracted Gradle directory.
   • Add %GRADLE_HOME%\bin to the PATH variable.

On Mac

1. Using Homebrew:

   brew install gradle
   

On Linux

1. Using SDKMAN:

   sdk install gradle
   

Verify the installation by running:

gradle -v

Step 2: Create a New Gradle Project

Navigate to the directory where you want to create your new Kotlin project and run the following command:

gradle init --type kotlin-application

This command initializes a new Gradle project with Kotlin support.

Step 3: Configure the build.gradle.kts File

Open the build.gradle.kts file and configure it to use the latest Kotlin and Gradle versions.

Example build.gradle.kts:

plugins {
    kotlin("jvm") version "1.9.0"
    application
}

repositories {
    mavenCentral()
}

dependencies {
    implementation(kotlin("stdlib"))
    testImplementation(kotlin("test"))
}

application {
    mainClass.set("com.example.MainKt")
}

tasks.withType<Test> {
    useJUnitPlatform()
}

Step 4: Update the Project Structure

Ensure your project structure follows the standard layout for a Kotlin project:

src/
├── main/
│   ├── kotlin/
│   │   └── com/
│   │       └── example/
│   │           └── Main.kt
│   └── resources/
└── test/
    ├── kotlin/
    │   └── com/
    │       └── example/
    │           └── MainTest.kt
    └── resources/

Move your source files to match this structure if necessary.

Step 5: Create a Simple Kotlin Application

Create a simple Kotlin application to test your setup.

Example Main.kt:

package com.example

fun main() {
    println("Hello, Kotlin!")
}

Example MainTest.kt:

package com.example

import kotlin.test.Test
import kotlin.test.assertEquals

class MainTest {

    @Test
    fun testMain() {
        assertEquals(4, 2 + 2)
    }
}

Step 6: Build and Run the Project

Use the following Gradle commands to build and run your project.

Build the Project

gradle build

Run the Application

gradle run

Run the Tests

gradle test

Step 7: Configure Additional Plugins and Settings

Gradle offers a variety of plugins that can enhance your Kotlin project. For example, you might want to add the Kotlin Spring plugin if you're building a Spring application or the Kotlin Android plugin for an Android project.

Example: Adding the Kotlin Spring Plugin

plugins {
    kotlin("jvm") version "1.9.0"
    kotlin("plugin.spring") version "1.9.0"
    application
}

dependencies {
    implementation("org.springframework.boot:spring-boot-starter-web")
    implementation("org.springframework.boot:spring-boot-starter-thymeleaf")
}

Conclusion

Setting up a Gradle project for Kotlin is straightforward and allows you to leverage the powerful features of both Gradle and Kotlin. By following this guide, you can create a new Kotlin project, configure it with Gradle, and start building your Kotlin applications efficiently. 

For more information, refer to the Gradle Kotlin DSL User Guide.