Oracle GraalVM in OCI Code Editor

This guide shows you how to get started with Oracle GraalVM in Oracle Cloud Infrastructure (OCI) Code Editor.

OCI Code Editor provides a rich, in-console editing environment that enables you to edit code without having to switch between the Oracle Cloud Console and your local development environment. The Code Editor enables you to edit and deploy code for OCI services directly from the OCI Console.

Oracle GraalVM JDK 17 with Native Image is preinstalled in Cloud Shell, so you do not have to install and configure a development machine. Code Editor’s integration with Cloud Shell gives you direct access to it.

Note: Oracle GraalVM license and support are included in the Oracle Cloud Infrastructure subscription at no additional cost.

Create and Run a Java Application in OCI Code Editor

Step 1: Open a Terminal in Code Editor

  1. Login to the Oracle Cloud Console and launch Code Editor.
  2. Open a Terminal in Code Editor, by clicking New Terminal from the Terminal menu.

Step 2: Select GraalVM JDK as the Default JDK

  1. List the installed JDKs using the csruntimectl java list command.

     csruntimectl java list

    The output lists the JDKs preinstalled in Cloud Shell: GraalVM for JDK 17, Oracle JDK 11, and Oracle JDK 8. The JDK marked with an asterisk is the current JDK.

  2. Select GraalVM for JDK 17 as the current JDK:

     csruntimectl java set graalvmeejdk-17

    You will see the confirmation message printed The current managed java version is set to graalvmeejdk-17.

  3. Now confirm the values of the environment variables PATH and JAVA_HOME, and the version of java, the native-image generator:

     echo $JAVA_HOME

     echo $PATH

     java -version

     native-image --version

Step 3: Setup a Java Project and Run

  1. Clone a demo repository and open it in OCI Code Editor. To achieve this, run the following commands one by one:

     git init graalvmee-java-hello-world

     cd graalvmee-java-hello-world

     git remote add origin https://github.com/oracle-devrel/oci-code-editor-samples.git

     git config core.sparsecheckout true

     echo "java-samples/graalvmee-java-hello-world/*">>.git/info/sparse-checkout

     git pull --depth=1 origin main

     cd java-samples/graalvmee-java-hello-world/

    You can now view/edit the sample code in Code Editor.

  2. Package the sample application into a runnable JAR:

     mvn clean package

  3. Run the JAR:

     java -jar target/my-app-1.0-SNAPSHOT.jar

    It prints out “Hello World!”.

Step 4: Build and Run a Native Executable

This Java application incorporates the Maven plugin for GraalVM Native Image that adds support for building native executables using Apache Maven. For testing purposes, build a native executable with the quick build mode first enabled and then disabled.

Quick Build Mode Enabled

  1. Build a native executable using the native Maven profile. The quick build mode is enabled for this run: notice the <buildArg>-Ob</buildArg> option in the plugin’s configuration in pom.xml.

     mvn clean -Pnative -DskipTests package

    This will generate a native executable for Linux in the target directory, named my-app.

  2. Run the app native executable in the background:

     ./target/my-app

Quick Build Mode Disabled

  1. To disable the quick build mode, comment out this line in pom.xml, as follows:

     <!-- <buildArg>-Ob</buildArg> -->

  2. Build a native executable again:

     mvn clean -Pnative -DskipTests package

    This will generate a native executable, my-app, in the target directory, replacing the previous one. You have probably noticed how the quick build mode reduced the time required to generate a native executable, making it easier to use Native Image in a typical development cycle (compile, test, and debug). However, the size of a generated executable is larger and peak performance is worse. The quick build mode is recommended for development purposes only.

  3. Run the native executable:

     ./target/my-app

Congratulations! You have successfully built and run a native executable using Oracle GraalVM in OCI Code Editor without the need to switch between the Oracle Cloud Console and your local development environments. The Code Editor allows you to accomplish quick coding tasks and run applications directly from the OCI Console.