Java

In addition to installing the JDK, you'll need to install either the Maven or Gradle build systems in your shell.

In both cases, you'll want to first activate devbox shell before generating your Maven or Gradle projects, so that the tools use the right version of the JDK for creating your project.

Example Repo

Adding the JDK to your project

devbox add jdk binutils, or in your devbox.json

  "packages": [
    "jdk@latest",
    "binutils@latest"
  ],

This will install the latest version of the JDK. To find other installable versions of the JDK, run devbox search jdk.

Other distributions of the JDK (such as OracleJDK and Eclipse Temurin) are available in Nixpkgs, and can be found using NixPkg Search

Gradle

Example Repo

Gradle is a popular, multi-language build tool that is commonly used with JVM projects. To setup an example project using Gradle, follow the instructions below:

1. Create a project folder: my-project/ and call devbox init inside it. Then add these packages: devbox add jdk and devbox add gradle.
   • Replace jdk with the version of JDK you want. Get the exact nix-pkg name from search.nixos.org.
2. Then do devbox shell to get a shell with that jdk nix pkg.
3. Then do: gradle init
   • In the generated build.gradle file, put the following text block:

     /* build.gradle */
     apply plugin: 'java'
     apply plugin: 'application'
     /* Change these versions to the JDK version you have installed */
     sourceCompatibility = 17
     targetCompatibility = 17
     mainClassName = 'hello.HelloWorld'
     jar {
         manifest {
           /* assuming main class is in src/main/java/hello/HelloWorld.java */
             attributes 'Main-Class': 'hello.HelloWorld'
         }
     }
   • While in devbox shell, run echo $JAVA_HOME and take note of its value.
   • Create a gradle.properties file like below and put value of $JAVA_HOME instead of <JAVA_HOME_VALUE> in the file.

     /* gradle.properties */
     org.gradle.java.home=\<JAVA_HOME_VALUE\>
4. gradle build should compile the package and create a build/ directory that contains an executable jar file.
5. gradle run should print "Hello World!".
6. Add build/ to .gitignore.

An example devbox.json would look like the following:

{
  "packages": [
    "gradle",
    "jdk",
    "binutils"
  ],
  "shell": {
    "init_hook": null
  }
}

Maven

Example Repo

Maven is an all-in-one CI-CD tool for building testing and deploying Java projects. To setup a sample project with Java and Maven in devbox follow the steps below:

1. Create a dummy folder: dummy/ and call devbox init inside it. Then add the nix-pkg: devbox add jdk and devbox add maven.
   • Replace jdk with the version of JDK you want. Get the exact nix-pkg name from search.nixos.org.
2. Then do devbox shell to get a shell with that jdk nix pkg.
3. Then do: mvn archetype:generate -DgroupId=com.devbox.mavenapp -DartifactId=devbox-maven-app -DarchetypeArtifactId=maven-archetype-quickstart -DarchetypeVersion=1.4 -DinteractiveMode=false
   • In the generated pom.xml file, replace java version in <maven.compiler.source> with the specific version you are testing for.
4. mvn package should compile the package and create a target/ directory.
5. java -cp target/devbox-maven-app-1.0-SNAPSHOT.jar com.devbox.mavenapp.App should print "Hello World!".
6. Add target/ to .gitignore.

An example devbox.json would look like the following:

{
  "packages": [
    "maven",
    "jdk",
    "binutils"
  ],
  "shell": {
    "init_hook": null
  }
}