Migrating Java 11 to Java 21
Migrating Java 11 to Java 21 is a technical, hands-on course designed to guide developers and engineers through the process of upgrading enterprise Java applications from Java 11 (LTS) to Java 21 (LTS). The course covers language changes, JVM enhancements, removed and deprecated features, performance improvements, and new APIs introduced between Java 11 and Java 21. Participants will learn how to assess application readiness, update build tools and dependencies, refactor incompatible code, and take advantage of modern Java features such as records, pattern matching, sealed classes, virtual threads, and enhanced garbage collection. By the end of the course, learners will be able to confidently plan and execute a safe, production-ready Java migration while minimizing risk and downtime.
- Understand the key differences between Java 11 and Java 21
- Identify deprecated, removed, and incompatible APIs and features
- Update build tools and dependencies (e.g., Maven or Gradle) for Java 21 compatibility
- Refactor legacy code to comply with newer Java language and JVM changes
- Apply modern Java language features such as records, sealed classes, and pattern matching
- Understand and leverage virtual threads for improved concurrency and scalability
- Evaluate JVM performance improvements and garbage collection enhancements
- Test and validate applications during and after migration
- Troubleshoot common migration issues and runtime errors
- Develop a structured migration strategy for production environments
- Java Developers responsible for maintaining or modernizing existing applications
- Backend Engineers working on enterprise Java systems
- Software Architects planning Java platform upgrades
- DevOps and Platform Engineers supporting Java-based services
- Organizations preparing to move to a modern Java LTS release
- Strong working knowledge of Java 11 or earlier
- Experience developing and maintaining Java applications
- Familiarity with build tools such as Maven or Gradle
- Basic understanding of JVM concepts and application deployment