Create Your First Gradle Project

Introduction

This chapter creates a real Gradle Java application two ways: gradle init (fast template) and a manual minimal layout (deep understanding). You will learn what each file does, run ./gradlew build, and execute a Hello World with the application plugin.

Prerequisites

• JDK 21
• Gradle on PATH or use Wrapper after generation (installation chapters)
• Optional: IntelliJ IDEA for import

Standard Gradle Java Layout

Same src convention as Maven—Gradle adopted it for compatibility.

Method A: gradle init (Recommended First)

Pick an empty parent folder:

mkdir ~/projects
cd ~/projects
gradle init

Answer the wizard (typical learning choices):

After init:

cd hello-gradle
./gradlew tasks
./gradlew build
./gradlew run

Windows:

gradlew.bat build
gradlew.bat run

You should see BUILD SUCCESSFUL and application output in the console.

Key Files After init

settings.gradle

// Root project name shown in IDEA and build output
rootProject.name = 'hello-gradle'

Multi-module projects add include 'submodule' here.

build.gradle (simplified example)

gradle/wrapper/gradle-wrapper.properties

Pins Wrapper version:

distributionUrl=https\://services.gradle.org/distributions/gradle-8.12.1-bin.zip

Commit Wrapper files so teammates need only JDK 21.

gradle.properties (optional)

org.gradle.jvmargs=-Xmx2g -Dfile.encoding=UTF-8
org.gradle.parallel=true

Method B: Manual Minimal Project

Create structure by hand:

mkdir -p manual-gradle/src/main/java/com/example
mkdir -p manual-gradle/src/test/java/com/example
cd manual-gradle

settings.gradle:

rootProject.name = 'manual-gradle'

build.gradle:

src/main/java/com/example/HelloApp.java:

package com.example;
 
public class HelloApp {
    public static void main(String[] args) {
        System.out.println("Hello from Gradle!");
    }
}

Generate Wrapper (needs global gradle once):

gradle wrapper --gradle-version 8.12.1
./gradlew build
./gradlew run

Common Gradle Tasks

./gradlew clean build

Outputs land under build/libs/ (JAR name includes project version).

Import into IntelliJ

1. Open the folder containing settings.gradle
2. Wait for Gradle sync
3. Run HelloApp from the gutter or Gradle → application → run

See IntelliJ and Gradle for JVM and distribution settings.

Compare with Maven Quickstart

Mini Exercise: Change the Greeting

1. Edit the main method message
2. Run ./gradlew run
3. Add a failing test, run ./gradlew test, fix it, run again

FAQ

build/ folder — commit to git?

No. Add build/ to .gitignore. Commit sources and Wrapper only.

Groovy vs Kotlin DSL?

Same concepts. Groovy build.gradle is common in Java samples; build.gradle.kts uses Kotlin syntax—popular in Kotlin projects.

gradlew: Permission denied on macOS/Linux?

Run chmod +x gradlew.

Init failed to pick Java 21?

Edit java { toolchain { languageVersion = JavaLanguageVersion.of(21) } } } manually.

What comes next?

Gradle Wrapper — deep dive into gradlew and upgrading versions.