Exploring Java Features: From Java 8 to Java 21

Java has been at the forefront of software development for decades, continually adapting to meet the needs of developers. From the revolutionary updates in Java 8 to the cutting-edge features in Java 21, the language has undergone tremendous growth. This article explores the most significant updates that have defined Java’s evolution, focusing on performance, developer productivity, and language flexibility.

Table of Contents

Java 8: Lambda and Streams Revolution

Java 8 marked a turning point in Java’s journey, introducing lambda expressions and enabling functional programming. These updates allowed developers to write more concise and expressive code.

The Streams API provided efficient data processing capabilities, making operations like filtering, mapping, and reduction seamless.
A new Date and Time API replaced the outdated java.util.Date, offering improved date manipulation.
Default methods in interfaces enhanced code reusability, enabling interface evolution without breaking implementations.
Compact Profiles reduced the memory footprint, optimizing Java for smaller devices.

Java 9: Modular Architecture

Java 9 introduced the Java Platform Module System (JPMS), allowing developers to create modular applications with better encapsulation.

JShell, an interactive REPL tool, simplified experimentation and learning.
Enhanced support for HTTP/2 improved web communication performance.
Updates to garbage collection enhanced memory management efficiency.

Java 10: Local Variable Type Inference

The highlight of Java 10 was the var keyword, which introduced local variable type inference, making code more concise and readable.

Application Class Data Sharing (CDS) reduced startup times, enhancing application performance.
Garbage collector optimizations further streamlined memory handling.

Java 11: Long-Term Support (LTS)

Java 11 cemented its position as a significant release by introducing:

A new HTTP client API for simpler and more reliable web communication.
Handy String methods like isBlank, lines, and repeat.
Lambda parameter syntax improvements for easier annotations.
The removal of JavaFX from the JDK, ensuring a more lightweight core.

Java 12 to Java 14: Incremental Innovations

Java 12

Switch expressions (preview) allowed more streamlined and expressive switch cases.
JVM optimizations improved performance.

Java 13

Text blocks made multiline strings effortless and more readable.

Java 14

Pattern matching for instanceof reduced boilerplate code.
Helpful NullPointerException messages simplified debugging.

Java 15 to Java 17: Sealing the Future

Java 15

Sealed classes provided developers with better control over class hierarchies.
Hidden classes enhanced framework development.

Java 16

Records made immutable data carriers simple to create.
API enhancements improved developer experience.

Java 17 (LTS)

Better support for macOS and deserialization filters for improved security made Java 17 a robust update.

Java 18 to Java 20: Focus on Performance

Java 18

Default UTF-8 charset ensured consistent encoding across platforms.
A simple web server was introduced for lightweight applications.

Java 19

Virtual threads brought lightweight concurrency, revolutionizing multi-threaded applications.
Structured concurrency APIs improved thread management.

Java 20

Refinements to Project Loom and the foreign function/memory API provided cutting-edge capabilities.

Java 21: Latest Features

Java 21 introduced revolutionary updates like:

Enhanced virtual threads, enabling highly scalable applications.
Continuous improvements in the foreign function and memory API.
Notable performance boosts and language refinements.