Set up a Gradle project

To create a Java application with Gradle (command line)

1. Create a directory to hold your project. In this example, demo is the directory name.

2. Inside the demo directory, execute the gradle init command and supply the values highlighted in red as shown in the following command line output. For the walk through, we choose Kotlin as the build script DSL language, but a complete example for Groovy is also shown at the end of this topic.

   > gradle init
   Starting a Gradle Daemon (subsequent builds will be faster)
   
   Select type of project to generate:
   1: basic
   2: application
   3: library
   4: Gradle plugin
   Enter selection (default: basic) [1..4] 2
   
   Select implementation language:
   1: C++
   2: Groovy
   3: Java
   4: Kotlin
   5: Scala
   6: Swift
   Enter selection (default: Java) [1..6] 3
   
   Generate multiple subprojects for application? (default: no) [yes, no] no
   Select build script DSL:
   1: Kotlin
   2: Groovy
   Enter selection (default: Kotlin) [1..2] <Enter>
   
   Select test framework:
   1: JUnit 4
   2: TestNG
   3: Spock
   4: JUnit Jupiter
   Enter selection (default: JUnit Jupiter) [1..4] 4
   
   Project name (default: demo): <Enter>
   Source package (default: demo): <Enter>
   Enter target version of Java (min. 7) (default: 11): <Enter>
   Generate build using new APIs and behavior (some features may change in the next minor release)? (default: no) [yes, no] <Enter>
   
   > Task :init
   To learn more about Gradle by exploring our Samples at https://docs.gradle.org/8.4/samples/sample_building_java_applications.html
   
   BUILD SUCCESSFUL in 3m 43s
   2 actionable tasks: 2 executed

3. After the init task completes, the demo directory contains the following tree structure. We take a closer look at the main build file, build.gradle.kts (highlighted in red), in the next section.

   ├── app
   │   ├── build.gradle.kts
   │   └── src
   │       ├── main
   │       │   ├── java
   │       │   │   └── demo
   │       │   │       └── App.java
   │       │   └── resources
   │       └── test
   │           ├── java
   │           │   └── demo
   │           │       └── AppTest.java
   │           └── resources
   ├── gradle
   │   └── wrapper
   │       ├── gradle-wrapper.jar
   │       └── gradle-wrapper.properties
   ├── gradlew
   ├── gradlew.bat
   └── settings.gradle.kts

   The build.gradle.kts file contains the following scaffolded content.

   /*
    * This file was generated by the Gradle 'init' task.
    *
    * This generated file contains a sample Java application project to get you started.
    * For more details on building Java & JVM projects, please refer to https://docs.gradle.org/8.4/userguide/building_java_projects.html in the Gradle documentation.
    */
   
   plugins {
       // Apply the application plugin to add support for building a CLI application in Java.
       application
   }
   
   repositories {
       // Use Maven Central for resolving dependencies.
       mavenCentral()
   }
   
   dependencies {
       // Use JUnit Jupiter for testing.
       testImplementation("org.junit.jupiter:junit-jupiter:5.9.3")
   
       testRuntimeOnly("org.junit.platform:junit-platform-launcher")
   
       // This dependency is used by the application.
       implementation("com.google.guava:guava:32.1.1-jre")
   }
   
   // Apply a specific Java toolchain to ease working on different environments.
   java {
       toolchain {
           languageVersion.set(JavaLanguageVersion.of(11))
       }
   }
   
   application {
       // Define the main class for the application.
       mainClass.set("demo.App")
   }
   
   tasks.named<Test>("test") {
       // Use JUnit Platform for unit tests.
       useJUnitPlatform()
   }
   

4. Use the scaffolded Gradle build file as the basis for your Amazon project.

   1. To manage SDK dependencies for your Gradle project, add the Maven bill of materials (BOM) for the Amazon SDK for Java 2.x to the dependencies section of the build.gradle.kts file.

      ...
      dependencies {
          implementation(platform("software.amazon.awssdk:bom:2.21.1"))
          // With the bom declared, you specify individual SDK dependencies without a version.
       ...
      }
      ...

      Note

      In this example build file, replace 2.21.1 with the latest version of the SDK for Java 2.x. Find the latest version available in Maven central repository.

   2. Specify the SDK modules your application needs in the dependencies section. As an example, the following adds a dependency on Amazon Simple Storage Service.

      ...
      dependencies {    
          implementation(platform("software.amazon.awssdk:bom:2.21.1"))
          implementation("software.amazon.awssdk:s3")
       ...
      }
      ...

      Gradle automatically resolves the correct version of declared dependencies by using the information from the BOM.