Java 11 New Features and Performance Improvements: A Practical Guide (2026-08-18 18:42)

Java 11, a Long-Term Support (LTS) release released in September 2018, marks one of the most significant milestones since Java 8. This post highlights the most impactful changes and their effects on real-world applications.

Java 11 introduces several language and API enhancements. The lambda parameter syntax for local variables, introduced in Java 10, is now available in Java 11. This allows for consistent annotation usage. Additionally, new String methods simplify common tasks. For instance, the isBlank() method checks if a string is empty or contains only whitespace, while strip() removes leading and trailing whitespace, handling Unicode whitespace characters correctly.

Other new methods include repeat() for repeating a string and streamlining file read/write operations.

The HTTP client, an incubator in Java 9, has now become standardized in Java 11 under java.net.http. It supports HTTP/2 and WebSocket, with both synchronous and asynchronous request handling options. Moreover, Java 11 simplifies running single-file source code directly, eliminating the need for the javac compilation step.

Performance improvements in Java 11 include the experimental Epsilon Garbage Collector (GC), which allocates memory without reclaiming it, useful for performance testing and benchmarking. Another experimental GC, ZGC, handles large heaps with exceptionally low pause times, making it suitable for latency-sensitive applications. The default G1 GC also received enhancements, such as faster full GCs and improved handling of aborted mixed collections.

Furthermore, Java Flight Recorder, previously a commercial feature, is now open source, providing low-overhead profiling and diagnostics data collection.