01-jvm-developers.md

layout	base
permalink	jvm-developers/
audience_identifier	jvm

Embed Python in JVM Applications with GraalPy

Python Packages in Java

Use Python packages directly in Java, Kotlin, or Scala

Jython Upgrade Path

Upgrade Jython projects to Python 3

JVM Scripting with Python

Script JVM applications with Python

How to Get Started

Add GraalPy as a dependency to your JVM application, or go straight to the starter project.

Without Python Dependencies

{%- highlight xml -%} org.graalvm.polyglot polyglot {{ site.language_version }} org.graalvm.polyglot python {{ site.language_version }} pom {%- endhighlight -%}

{%- highlight java -%} import org.graalvm.polyglot.Context;

try (Context context = Context.newBuilder().build()) { context.eval("python", "print('Hello from GraalPy!')"); } {%- endhighlight -%}

{%- highlight groovy -%} dependencies { implementation("org.graalvm.polyglot:polyglot:{{ site.language_version }}") implementation("org.graalvm.polyglot:python:{{ site.language_version }}") } {%- endhighlight -%}

{%- highlight java -%} import org.graalvm.polyglot.Context;

try (Context context = Context.newBuilder().build()) { context.eval("python", "print('Hello from GraalPy!')"); } {%- endhighlight -%}

With Python Dependencies

{%- highlight xml -%} org.graalvm.python python-embedding {{ site.language_version }} org.graalvm.python graalpy-maven-plugin {{ site.language_version }} pyfiglet==1.0.2 process-graalpy-resources {%- endhighlight -%}

{%- highlight java -%} import org.graalvm.polyglot.Context; import org.graalvm.python.embedding.GraalPyResources;

try (Context context = GraalPyResources.contextBuilder().build()) { context.eval("python", """ from pyfiglet import Figlet f = Figlet(font='slant') print(f.renderText('Hello from GraalPy!')) """); } {%- endhighlight -%}

{%- highlight groovy -%} plugins { id "org.graalvm.python" version "{{ site.language_version}}" }

dependencies { implementation("org.graalvm.python:python-embedding:{{ site.language_version }}") }

graalPy { packages = ["pyfiglet==1.0.2"] } {%- endhighlight -%}

{%- highlight java -%} import org.graalvm.polyglot.Context; import org.graalvm.python.embedding.GraalPyResources;

try (Context context = GraalPyResources.contextBuilder().build()) { context.eval("python", """ from pyfiglet import Figlet f = Figlet(font='slant') print(f.renderText('Hello from GraalPy!')) """); } {%- endhighlight -%}

<script> $(document).ready(function () { $('[data-jvm-get-started-group]').each(function () { const getStartedGroup = $(this); const getStartedItems = getStartedGroup.find('.compatibility_page-item[role="tab"]'); const getStartedPanels = getStartedGroup.find('.get-started-panel'); function activateGetStartedTab(tab, options) { const settings = options || {}; const target = tab.attr('data-target'); getStartedItems .removeClass('compatibility_page-active') .attr('aria-selected', 'false') .attr('tabindex', '-1'); tab .addClass('compatibility_page-active') .attr('aria-selected', 'true') .attr('tabindex', '0'); getStartedPanels.attr('hidden', true); getStartedGroup.find(`#${target}`).removeAttr('hidden'); const toolSuffix = target.includes('-maven') ? '-maven' : '-gradle-java'; $('[data-jvm-get-started-group]').not(getStartedGroup).each(function () { const otherGroup = $(this); const otherItems = otherGroup.find('.compatibility_page-item[role="tab"]'); const otherPanels = otherGroup.find('.get-started-panel'); const matchingTab = otherItems.filter(`[data-target$="${toolSuffix}"]`); if (!matchingTab.length) { return; } otherItems .removeClass('compatibility_page-active') .attr('aria-selected', 'false') .attr('tabindex', '-1'); matchingTab .addClass('compatibility_page-active') .attr('aria-selected', 'true') .attr('tabindex', '0'); otherPanels.attr('hidden', true); otherGroup.find(`#${matchingTab.attr('data-target')}`).removeAttr('hidden'); }); if (settings.focus) { tab.trigger('focus'); } } getStartedItems.on('click', function () { activateGetStartedTab($(this)); }); getStartedItems.on('keydown', function (event) { const currentIndex = getStartedItems.index(this); let nextIndex = null; if (event.key === 'ArrowRight') { nextIndex = (currentIndex + 1) % getStartedItems.length; } else if (event.key === 'ArrowLeft') { nextIndex = (currentIndex - 1 + getStartedItems.length) % getStartedItems.length; } else if (event.key === 'Home') { nextIndex = 0; } else if (event.key === 'End') { nextIndex = getStartedItems.length - 1; } if (nextIndex !== null) { event.preventDefault(); activateGetStartedTab(getStartedItems.eq(nextIndex), { focus: true }); } }); }); }); </script>

Guides

Embed GraalPy in Java Applications

Use GraalPy with Maven or Gradle in a Java SE Application

Freeze Transitive Python Dependencies for Reproducible Builds

Use GraalPy with Spring Boot

Use GraalPy with Micronaut

Manually Install Python Packages

Use GraalPy Maven Plugin to Install Python Native Extensions

Demos

Debug Python Scripts in VS Code with GraalPy

GraalPy OpenAI Starter

GraalPy JBang QRCode

SVG Charts with GraalPy and Spring Boot

SVG Charts with GraalPy and Micronaut

Videos

Tips and Tricks for GraalVM and Graal Languages

In this session, Fabio Niephaus from the GraalVM team shows his favourite tips and tricks for using GraalPy and other Graal Languages in IntelliJ IDEA. He also shows how to use IntelliJ IDEA as a multi-language IDE. Language injections and support for various debugging protocols make it easy to embed and debug code written in languages like Python in Java applications.

Supercharge your Java Applications with Python!
Jfokus'25

Projects such as LangChain4j, Spring AI, and llama3.java got the Java community very excited about AI in the last year. The Python ecosystem also provides many powerful packages for data science, machine learning, and more. Wouldn't it be cool if you, as a Java developer, could benefit from this, too?
In this talk, we show how you can get started with GraalPy and use packages from the Python ecosystem. We also show some live demos and preview upcoming features that will improve the interaction between Java and native extensions that ship with popular Python packages.