Java/Java SE 8: What's New, Release History & Support Lifecycle

What is New in Java 8

Java 8 introduced major changes to make programming more productive and efficient. It added functional programming features like lambda expressions and streams, improved date and time handling, and enhanced tools for concurrency and scripting. These updates help developers write cleaner, more concise code while boosting performance in data processing and parallel tasks.

Lambda Expressions

Lambda expressions let you write anonymous functions in a compact way. They simplify code for interfaces with a single method, like comparators or event handlers.

// Before Java 8
Runnable r = new Runnable() {
    public void run() {
        System.out.println("Hello");
    }
};

// With lambda
Runnable r = () -> System.out.println("Hello");

Streams API

Streams provide a functional way to process collections of data. They support operations like filter, map, and reduce, and can run in parallel for better speed.

List<Integer> numbers = Arrays.asList(1, 2, 3, 4);
int sum = numbers.stream()
    .filter(n -> n % 2 == 0)
    .mapToInt(n -> n)
    .sum(); // Result: 6

New Date and Time API

The java.time package replaces old Date and Calendar classes. It offers immutable, thread-safe classes for dates, times, durations, and time zones.

LocalDate today = LocalDate.now();
LocalTime time = LocalTime.of(10, 30);
Duration duration = Duration.between(time, LocalTime.now());

Functional Interfaces and Default Methods

Functional interfaces are those with exactly one abstract method, marked by @FunctionalInterface. Default methods let you add new methods to interfaces without breaking existing code.

@FunctionalInterface
interface MyFunc {
    void doSomething();
    default void log() {
        System.out.println("Logging");
    }
}

Nashorn JavaScript Engine

A new high-performance engine to run JavaScript inside Java applications. It replaces Rhino and supports ECMAScript 5.1.

ScriptEngine engine = new ScriptEngineManager().getEngineByName("nashorn");
engine.eval("print('Hello from JS')");

Other Key Improvements

- Optional class to avoid null pointer exceptions.

- CompletableFuture for asynchronous programming.

- Type annotations for better static analysis.

- Improved tools like jjs for running scripts and jdeps for dependency analysis.

- Enhanced performance in HotSpot JVM with new garbage collectors like G1 as default.

Removals and Changes

Some old features were deprecated or removed for modernization.

Why Java 8 Matters

Java 8 transformed the language with functional programming and better APIs. It makes code shorter and easier to maintain, especially for data-heavy applications. As an LTS version, it remains widely used for its stability and features that influenced later releases.