Supercharge your Java Applications with Python! by Fabio Niephaus, Thomas Wuerthinger

GraalPy allows Java developers to embed Python code within Java applications while maintaining full control and security through sandboxing capabilities

Languages like GraalPy, GraalJS, and GraalWasm can run on any OpenJDK distribution, not just GraalVM - they’re implemented as regular Java libraries accessible via Maven/Gradle dependencies

Integration is straightforward through Maven/Gradle dependencies - only requires Java 21+ and adding the polyglot package plus specific language dependencies

Major benefits include:

• No data/memory overhead between languages
• Single process deployment
• Shared garbage collection
• Full IDE support including debugging
• Production-ready performance

Currently supports Python 3.11 with work ongoing for 3.12 compatibility, along with the top 500 Python packages

Native Python extensions require recompilation for GraalPy, but the team is working on automating this process and publishing pre-compiled versions to Maven Central

Multi-threading considerations:

• Python contexts should be pooled for multi-threaded applications
• Single Python context cannot be used across multiple threads

Real-world production usage examples:

• IntelliJ IDEA using GraalJS for HTTP client execution
• Oracle Database embedding
• Amazon implementations

Build options include:

• Regular JIT compilation
• Native image compilation
• Interpreter-only mode for smaller deployments

Active development continues on framework integrations with Spring, Micronaut, and Quarkus to provide more convenient developer experiences