1. Introduction

Java 11, released as a Long-Term Support (LTS) version in September 2018, brought several important improvements that modernize the platform, simplify code, and improve runtime performance. It is defined by the official platform specification: JSR 384 – Java SE 11 Platform Specification. In this article, we’ll explore five key features introduced in JDK 11 that every Java developer should know.

⚠️ Note: JDK 11 removes several deprecated APIs and modules. Be sure to test legacy code for compatibility before upgrading.

2. Local-Variable Syntax for Lambda Parameters (JEP 323)

JEP 323 allows the use of var in lambda parameter declarations, enabling type annotations for lambda parameters without sacrificing conciseness.

var list = List.of("Java", "11", "LTS");
list.forEach((var item) -> System.out.println(item.toUpperCase()));

Why it matters: Enables cleaner code and allows annotations like @Nonnull on lambda parameters.

3. HTTP Client Standardized (JEP 321)

JEP 321 standardizes the HTTP Client API introduced as an incubator in JDK 9. It supports HTTP/1.1, HTTP/2, and WebSocket.

HttpClient client = HttpClient.newHttpClient();
HttpRequest request = HttpRequest.newBuilder()
    .uri(URI.create("https://example.com"))
    .build();
HttpResponse<String> response = client.send(request, HttpResponse.BodyHandlers.ofString());
System.out.println(response.body());

Why it matters: Provides a modern, non-blocking HTTP client in the core JDK.

4. String Methods Enhancements

JDK 11 adds new utility methods to String, including isBlank(), lines(), strip(), and repeat(int).
These enhancements were introduced as part of the standard Java API update and were not covered by a specific JEP.

System.out.println("  Hello  ".strip());
System.out.println("Java\n11\nRocks".lines().count());
System.out.println("Hi! ".repeat(3));
System.out.println("   ".isBlank());

Why it matters: Reduces the need for external libraries or verbose utility code.

5. Files.readString() and writeString() (JEP 330)

JEP 330 introduced simplified methods to read and write files using String.

Path file = Path.of("example.txt");
Files.writeString(file, "Java 11 is productive!");
String content = Files.readString(file);
System.out.println(content);

Why it matters: Makes file I/O easier and more intuitive.

6. Running Java Files Without Compilation (JEP 330)

JEP 330 allows executing a Java file directly using the java launcher without explicitly compiling it.

java HelloWorld.java

Why it matters: Great for scripting, quick demos, or learning — no manual compilation needed.

7. Conclusion

Java 11 focused on improving developer productivity, standardizing core APIs, and simplifying code. These features continue to make Java a robust and modern programming language. Whether you’re migrating from Java 8 or starting fresh, understanding these key additions will help you write cleaner, faster, and more expressive Java code.

You can find the complete code of this article here in GitHub.