Introduction
The landscape of enterprise Java development is undergoing a significant shift with the transition from Java EE (Java Platform, Enterprise Edition) to Jakarta EE. The change represents not only a shift in branding but also a deeper evolution of the platform under the stewardship of the Eclipse Foundation. For Java professionals, the migration from Java EE to Jakarta EE is inevitable, and understanding the key considerations for a smooth transition is crucial.
In this article, we will explore the essential factors to keep in mind when migrating Java EE applications to Jakarta EE. This includes understanding the changes in naming conventions, the potential impact on your application code, new features and improvements in Jakarta EE, and the best practices for a seamless migration process. By the end of this guide, you’ll be better equipped to handle the migration with minimal disruption.
What is the Difference Between Java EE and Jakarta EE?
Before diving into the migration process, it’s essential to understand what Jakarta EE is and how it differs from Java EE.
- Java EE: Java EE was originally developed by Sun Microsystems and later acquired by Oracle. It was a widely used enterprise platform for developing large-scale, multi-tiered applications. It included technologies such as Servlets, JSP (JavaServer Pages), EJB (Enterprise JavaBeans), JPA (Java Persistence API), and more.
- Jakarta EE: Jakarta EE is the evolution of Java EE, now governed by the Eclipse Foundation. The transition began after Oracle’s decision to donate Java EE to Eclipse, leading to the formation of Jakarta EE. The most noticeable change in Jakarta EE is the renaming of all Java EE packages. For example,
javax.persistencebecomesjakarta.persistence. This change is a result of Oracle’s decision to retain the Java trademark while relinquishing control over the enterprise edition to the Eclipse Foundation.
While Jakarta EE offers continued support for Java EE-based applications, it introduces new features, updates, and optimizations. One of the major changes is the shift to a more cloud-native and microservices-oriented approach, which is essential for modern enterprise applications.
Key Considerations When Migrating from Java EE to Jakarta EE
Migrating from Java EE to Jakarta EE is a critical step for Java professionals. The transition is not just about changing the framework’s name but also involves a few technical and architectural considerations. Below are the key aspects to focus on during the migration process:
1. Package Renaming and Namespace Changes
One of the most significant changes in Jakarta EE is the renaming of package names. Java EE packages were prefixed with javax.*, while Jakarta EE packages now begin with jakarta.*. This means that the namespace of various Java EE APIs has changed, requiring changes in the source code, configuration files, and libraries.
For example:
- Java EE:
javax.persistence.Entity - Jakarta EE:
jakarta.persistence.Entity
Actionable Steps:
- Update all import statements in your Java classes.
- Review all third-party libraries or dependencies you use to ensure they are compatible with Jakarta EE.
- Modify
persistence.xmlor other configuration files that reference Java EE APIs.
2. Upgrading Dependencies and Libraries
Another consideration when migrating is the compatibility of existing third-party libraries and frameworks. Many libraries designed for Java EE may not be compatible with Jakarta EE out-of-the-box. As Jakarta EE evolves, it may introduce new APIs, while certain Java EE libraries may be deprecated or no longer supported.
Actionable Steps:
- Review your project dependencies to ensure they support Jakarta EE.
- Update libraries such as Hibernate, Apache Tomcat, or other Jakarta EE-compatible implementations.
- Check the compatibility of popular Java EE tools like JBoss/WildFly, GlassFish, Payara, or TomEE, which have already moved to support Jakarta EE.
3. JDK Compatibility and Version Upgrades
Jakarta EE 9+ is designed to work seamlessly with Java 8 or higher. As part of the migration, you should assess whether your application is compatible with the latest Java versions (Java 11, Java 17, etc.), as Jakarta EE 9 and beyond will require at least Java 8.
Actionable Steps:
- Update your development environment to the appropriate Java version.
- Test your application for compatibility with Java 11, 17, or the latest long-term support (LTS) versions.
- Evaluate the use of new language features (e.g., records, pattern matching, etc.) introduced in Java 16 and beyond to modernize your codebase.
4. New Jakarta EE Features and Enhancements
Jakarta EE brings several improvements over Java EE, such as enhanced security features, better integration with microservices, cloud-native capabilities, and performance optimizations. These advancements can significantly improve your application architecture.
Some key improvements include:
- Cloud-Native Support: Jakarta EE 9 and beyond are optimized for cloud-native applications. This includes better integration with container orchestration platforms like Kubernetes and Docker.
- MicroProfile Integration: Jakarta EE has strong alignment with MicroProfile, which focuses on building microservices architectures. This includes features like configurations, fault tolerance, health checks, and JWT authentication.
- Improved CDI (Contexts and Dependency Injection): CDI has seen performance improvements, new annotations, and more flexible event handling.
Actionable Steps:
- Take advantage of new Jakarta EE features and enhancements where applicable.
- Reassess your application’s architecture to take advantage of cloud-native capabilities and microservices support.
- Explore the use of MicroProfile for building modern, lightweight microservices-based applications.
5. Testing and Validation
A critical aspect of the migration process is ensuring that your application continues to function as expected. Comprehensive testing is vital to identifying any breaking changes or issues introduced during the migration.
Actionable Steps:
- Write unit tests and integration tests to validate that your application behaves correctly after migration.
- Test the integration of Jakarta EE components (like CDI, JPA, EJB, etc.) to ensure that the migration does not introduce unexpected behavior.
- Use tools like JUnit, Arquillian, or Testcontainers to facilitate end-to-end testing of Jakarta EE applications.
6. Application Server Support
Many Java EE applications run on specific application servers (e.g., WildFly, Payara, TomEE, GlassFish). These application servers have now transitioned to Jakarta EE, but the migration might require some configuration changes to accommodate the new platform.
Actionable Steps:
- Ensure that your chosen application server supports Jakarta EE and is updated to a version compatible with Jakarta EE.
- If necessary, migrate from legacy application servers like GlassFish to Jakarta EE-supported versions (e.g., Payara).
- Review any custom configurations or deployments to ensure compatibility with Jakarta EE.
7. Performance Optimization
Jakarta EE is designed to be more lightweight and optimized for modern application development. However, migrating applications to Jakarta EE may require additional performance tuning.
Actionable Steps:
- Profile the performance of your application before and after the migration to identify any bottlenecks.
- Optimize Jakarta EE configurations and adjust settings for better concurrency and resource management.
Best Practices for Migrating from Java EE to Jakarta EE
Migrating your Java EE applications to Jakarta EE can be a smooth process if you follow the right approach. Below are some best practices to consider during migration:
- Start Small and Incrementally Migrate: If your application is large, it might be beneficial to migrate incrementally rather than all at once. Start with non-critical components and gradually migrate the entire system.
- Use Jakarta EE-Compatible Tools: Leverage tools that are already designed for Jakarta EE, such as Jakarta EE SDKs, MicroProfile, and Jakarta EE-compatible application servers.
- Prepare for Cloud Deployment: If your application needs to scale, consider using Jakarta EE’s cloud-native capabilities for containerization, Kubernetes, and microservices architecture.
- Collaborate with Your Team: Ensure your development, operations, and QA teams are aligned throughout the migration process. Collaboration is key to identifying potential issues and addressing them early.
- Stay Updated with Jakarta EE Releases: Jakarta EE is evolving rapidly. Make sure you keep track of the latest releases and patches for Jakarta EE 9 and beyond to leverage the newest features and fixes.
External Resources
- Jakarta EE Official Website
- Jakarta EE Migration Guide
- Eclipse Foundation – Jakarta EE
- Payara – Jakarta EE Support
Frequently Asked Questions (FAQs)
- What are the main differences between Java EE and Jakarta EE?
- The primary difference is the renaming of packages from
javax.*tojakarta.*as well as new features like better cloud-native support, microservices integration, and optimized performance.
- The primary difference is the renaming of packages from
- Is Jakarta EE backward-compatible with Java EE?
- Jakarta EE is mostly backward-compatible with Java EE, but due to package renaming and some API changes, there may be the need for code adjustments.
- Do I need to upgrade my JDK to use Jakarta EE?
- Jakarta EE supports JDK 8 and higher, so you should ensure your JDK is at least version 8. It is recommended to use a newer LTS version, like JDK 11 or 17.
- How do I handle third-party libraries in Jakarta EE?
- You need to ensure that the third-party libraries you use are compatible with Jakarta EE. Update libraries that are still using the
javax.*namespaces.
- You need to ensure that the third-party libraries you use are compatible with Jakarta EE. Update libraries that are still using the
- Can I continue using my existing application server with Jakarta EE?
- Many application servers like WildFly, Payara, and TomEE support Jakarta EE, but you may need to upgrade to their latest versions.
- Is MicroProfile part of Jakarta EE?
- Yes, Jakarta EE aligns closely with MicroProfile, which focuses on microservices-based development.
- How can I optimize my Jakarta EE application for the cloud?
- Take advantage of Jakarta EE’s cloud-native capabilities, including containerization, Kubernetes, and microservices architecture.
- Is there a migration tool for Java EE to Jakarta EE?
- While there isn’t a single official migration tool, there are several guides and resources available to help ease the migration process.
- Can I use Jakarta EE with non-Java languages?
- Jakarta EE is Java-centric, but you can integrate it with other technologies via RESTful APIs, SOAP, and other protocols.
- What should I do if my application fails after migration?
- If issues occur post-migration, debug and check the logs for errors related to package renaming or incompatible dependencies. Also, ensure your application server supports Jakarta EE properly.
Conclusion
Migrating from Java EE to Jakarta EE offers significant advantages for Java professionals, including improved cloud-native support, performance optimizations, and better alignment with microservices architectures. However, the process requires careful planning, attention to details like package renaming, updating dependencies, and leveraging Jakarta EE’s modern features. By following the outlined best practices and considerations, developers can ensure a smooth transition and future-proof their enterprise applications.