Java 11 New Features and Performance Improvements Released in September 2018, Java 11 is a Long-Term Support (LTS) release, making it one of the most important milestones since Java
8.
For teams planning migrations, Java 11 offers a compelling mix of new language features, API enhancements, and under-the-hood performance improvements.
In this post, we'll explore the most impactful changes and how they affect real-world applications.
Why Java 11 Matters Java 11 is the first LTS release after Java 8, meaning it receives extended support and security updates.
Unlike the non-LTS releases (9 and 10), it's designed for production stability, which is why many enterprises skipped straight from 8 to
11.
Language and API Enhancements
1.
Local-Variable Syntax for Lambda Parameters Java 10 introduced for local variables.
Java 11 extends this to lambda parameters, allowing you to apply annotations consistently.
2.
New String Methods The class gained several convenient methods that reduce boilerplate.
Note: differs from because it uses , correctly handling Unicode whitespace characters.
3.
Files Read/Write Convenience Methods Reading and writing strings to files is now a one-liner.
4.
The New HTTP Client (Standardized) Introduced as an incubator in Java 9, the API is now standardized under .
It supports HTTP/2 and WebSocket, and offers both synchronous and asynchronous request handling.
5.
Running Single-File Source Code You can now run a Java source file directly without explicit compilation—ideal for scripting and quick prototypes.
No step required.
Performance Improvements
1.
Epsilon Garbage Collector (Experimental) The Epsilon GC is a "no-op" garbage collector that allocates memory but never reclaims it.
It's useful for performance testing, short-lived jobs, and measuring GC overhead.
Use it to benchmark allocation rates without GC interference.
Do not use it in typical long-running production services—the application will crash once memory is exhausted.
2.
Z Garbage Collector (Experimental) ZGC is a scalable, low-latency garbage collector designed for large heaps (multi-terabyte) with pause times under 10ms, regardless of heap size.
ZGC performs most of its work concurrently, making it ideal for latency-sensitive applications.
It became production-ready in later releases (Java 15), but Java 11 is where it first appeared.
3.
Improved G1 Garbage Collector The default G1 GC received several enhancements in Java 11: Faster full GCs via a parallelized full GC algorithm (previously single-threaded).
Better handling of aborted mixed collections.
These changes reduce worst-case pause times for applications still using the default collector.
4.
Flight Recorder Now Open Source Java Flight Recorder (JFR), previously a commercial feature, is now open source and included in the OpenJDK.
It provides low-overhead profiling and diagnostics data collection.
Combined with JDK Mission Control (JMC), JFR gives you deep insight into application behavior with minimal runtime cost (typically under 1%).
Removed and Deprecated Features Migrating from Java 8?
Be aware of these removals: Java EE and CORBA modules (, , , etc.) were removed.
Add JAXB and JAX-WS as external dependencies if needed.