Java has been evolving rapidly, and with each new release, it introduces features that enhance developer productivity, improve performance, and address emerging challenges. Starting from Java 9, the platform has adopted a time-driven release model, which means features are delivered in a more predictable and timely manner. Let’s explore some notable features introduced in Java 9 and subsequent versions.
Java 9 Features:
1. Module System (Project Jigsaw):
- Java 9 introduced the module system to enhance the modularity of Java applications. It allows developers to create modular JARs, which can declare dependencies and encapsulate implementation details. This feature brings a more scalable and maintainable structure to large codebases.
module com.example.myapp {
requires java.base;
requires java.sql;
exports com.example.mymodule;
}2. JShell:
- JShell, also known as the REPL (Read-Eval-Print Loop), provides an interactive way to evaluate Java snippets and experiment with code. It simplifies the learning process and allows developers to quickly test code fragments.
jshell> int sum = 5 + 3
sum ==> 83. Immutable Collections:
- Java 9 introduced a set of immutable collection classes in the
java.utilpackage, includingList,Set, andMap. These collections do not allow modification after creation, promoting a more functional programming style.
List<String> immutableList = List.of("apple", "banana", "orange");4. Private Methods in Interfaces:
- Java 9 allows interfaces to have private methods, enabling code reuse within the interface without exposing those methods to implementing classes.
public interface MyInterface {
default void publicMethod() {
// Public method logic
privateMethod();
}
private void privateMethod() {
// Private method logic
}
}Java 10 Features:
1. Local-Variable Type Inference (var):
- Java 10 introduced local-variable type inference, allowing developers to use the
varkeyword to declare local variables with inferred types.
var list = new ArrayList<String>();2. Garbage-Collector Interface:
- Java 10 introduced the
GarbageCollectorMXBeaninterface to provide information about the garbage collectors available in the Java Virtual Machine (JVM).
List<GarbageCollectorMXBean> garbageCollectors = ManagementFactory.getGarbageCollectorMXBeans();Java 11 Features:
1. HTTP Client (Standardized):
- Java 11 introduced a standardized HTTP client to simplify the process of sending HTTP requests and processing responses.
HttpClient client = HttpClient.newHttpClient();
HttpRequest request = HttpRequest.newBuilder()
.uri(URI.create("https://www.example.com"))
.build();
HttpResponse<String> response = client.send(request, HttpResponse.BodyHandlers.ofString());2. Local-Variable Syntax for Lambda Parameters:
- Java 11 extended the
varsyntax to lambda expressions, allowing the use ofvarfor lambda parameters.
BiFunction<Integer, Integer, Integer> add = (var a, var b) -> a + b;Java 12 Features:
1. Switch Expression (Preview):
- Java 12 introduced a preview feature for switch expressions, providing a more concise syntax for switch statements.
int dayOfWeek = 3;
String dayType = switch (dayOfWeek) {
case 1, 2, 3, 4, 5 -> "Weekday";
case 6, 7 -> "Weekend";
default -> throw new IllegalArgumentException("Invalid day: " + dayOfWeek);
};Java 13 and Beyond:
Subsequent Java releases have continued to bring improvements, but it’s important to note that the feature set may vary. Some notable themes and features in recent releases include:
- Text Blocks (Java 13):
- Text blocks provide a more readable way to express multiline strings in Java.
String html = """
<html>
<body>
<p>Hello, Java 13!</p>
</body>
</html>
""";- Records (Java 14):
- Records provide a concise way to create immutable data-carrying classes.
record Point(int x, int y) {}- Pattern Matching for
instanceof(Java 14): - Pattern matching simplifies common code patterns, making it more concise and less error-prone.
if (obj instanceof String s) {
System.out.println(s.length());
}- Sealed Classes (Java 15):
- Sealed classes restrict which classes or interfaces can extend or implement them.
sealed interface Shape permits Circle, Rectangle {
// Interface definition
}- Foreign Function and Memory API (Incubator, Java 16):
- The Foreign Function and Memory API, in the incubator stage, aims to provide a pure Java API for calling native code and working with native memory.
These features represent just a subset of the advancements in Java after version 9. The Java platform continues to evolve, addressing the changing needs of developers and providing a more modern and expressive programming experience. Developers are encouraged to explore the latest releases and leverage the features that align with their application requirements.