Java 11 Features: What Every Developer Should Know

Java 11, released in September 2018, marked the second Long-Term Support (LTS) version after Java 8. It brought several key improvements and changes that every Java developer should be aware of. Whether you're upgrading from Java 8 or just curious, here’s a rundown of the most impactful features.

1. var in Lambda Parameters

Java 11 allows the use of var in lambda expressions:

(list) -> list.size()          // Old
(var list) -> list.size()      // Java 11

This is particularly useful when annotations are required:

(@Nonnull var item) -> System.out.println(item);

2. HTTP Client (Standard)

Java 11 standardized the HTTP Client API introduced in Java 9. It supports HTTP/1.1 and HTTP/2 and replaces the older HttpURLConnection.

HttpClient client = HttpClient.newHttpClient();
HttpRequest request = HttpRequest.newBuilder()
    .uri(URI.create("https://api.example.com/data"))
    .build();

HttpResponse<String> response = client.send(request, HttpResponse.BodyHandlers.ofString());
System.out.println(response.body());

3. Removed Deprecated APIs and Features

Several older modules were removed:

• Java EE modules (like java.xml.ws, java.activation)
• java.se.ee aggregate module
• JAXB, JAX-WS, CORBA, and others

If your code depends on them, you'll need to add external libraries.

4. String API Enhancements

Java 11 adds several useful methods to the String class:

" ".isBlank();          // true
"  abc  ".strip();      // "abc"
"abc\n".stripTrailing();// "abc"
"line1\nline2".lines(); // Stream of lines

5. File Reading Made Simple

A new method Files.readString(Path) simplifies file reading:

Path path = Path.of("file.txt");
String content = Files.readString(path);

6. Local-Variable Syntax for Lambda Parameters

This allows a consistent style for type declarations and helps in adding annotations:

(var x, var y) -> x + y

Previously, you couldn't mix var and explicit types in lambdas.

7. Launch Single-File Java Source Code

You can now run a single .java file directly from the command line without compiling:

java HelloWorld.java

This makes Java much more beginner-friendly and scripting-like.

8. ZGC (Z Garbage Collector)

Introduced as an experimental feature, ZGC is a scalable, low-latency garbage collector ideal for applications requiring large heap sizes and short pause times.

Enable it using:

-XX:+UseZGC

🔚 Final Thoughts

Java 11 is a powerful, stable upgrade from Java 8, bringing modern features, better performance, and a more streamlined API. With long-term support, it’s a great choice for both enterprise and personal projects.

Are you still on Java 8? Now's the time to upgrade.