Hello Java developers! If you’ve been working with Java for a while, you know that each release brings along exciting new features and improvements. Java 17, like its previous versions, offers a range of enhancements that can make your coding journey smoother and more efficient. In this blog post, we’ll explore some key features introduced between Java 11 and Java 17. Let’s dive in!
Records (JEP 395)
What is it?
Records provide a compact way to declare classes that are holders of immutable data. They can help reduce boilerplate code for simple data carrier classes.
Example:
// Java 11 style class for Point
public class Point {
private final int x;
private final int y;
public Point(int x, int y) {
this.x = x;
this.y = y;
}
// Getters and other methods
}
// Java 17 style record
public record Point(int x, int y) { }Pattern Matching for switch (JEP 406)
What is it?
Java 17 introduced enhancements to pattern matching for switch expressions. This feature lets you destructure objects directly within a switch expression, making your code more concise and readable.
Example:
// Java 11 style switch statement
String day = "Monday";
switch (day) {
case "Monday":
case "Wednesday":
case "Friday":
System.out.println("It's a workday");
break;
case "Saturday":
case "Sunday":
System.out.println("It's the weekend");
break;
default:
System.out.println("Invalid day");
}
// Java 17 style switch expression
String day = "Monday";
String typeOfDay = switch (day) {
case "Monday", "Wednesday", "Friday" -> "It's a workday";
case "Saturday", "Sunday" -> "It's the weekend";
default -> "Invalid day";
};
System.out.println(typeOfDay);Sealed Classes (JEP 409)
What is it?
Sealed classes provide a mechanism to control which classes can extend or implement a given class or interface. This helps in designing more robust and maintainable code by restricting the inheritance hierarchy.
Example:
// Define a sealed interface
sealed interface Shape permits Circle, Rectangle, Triangle { }
// Sealed classes implementing the interface
final class Circle implements Shape { /* ... */ }
final class Rectangle implements Shape { /* ... */ }
final class Triangle implements Shape { /* ... */ }
Pattern Matching for instanceof (JEP 394)
What is it?
Similar to pattern matching for switch, Java 17 introduces pattern matching for the instanceof operator. This allows you to cast and use the type in a single step.
Example:
// Java 11 style
if (obj instanceof String) {
String s = (String) obj;
System.out.println(s.length());
}
// Java 17 style with pattern matching
if (obj instanceof String s) {
System.out.println(s.length());
}
New Garbage Collectors
What is it?
Java 17 introduced two new experimental garbage collectors: ZGC (Z Garbage Collector) and Shenandoah. These collectors aim to provide low-latency and high-throughput garbage collection options.
Example:
To enable ZGC, you can use the following JVM option:
java -XX:+UseZGC YourApplicationConclusion
Java 17 brings a lot of features that enhance productivity, maintainability, and performance. While migrating from Java 11 to 17 might require some adjustments, leveraging these new features can significantly benefit your applications. Stay tuned for more updates, and happy coding!
Remember, this is just a glimpse of what Java 17 offers. Exploring the official documentation and experimenting with these features will provide you with a deeper understanding and appreciation of the Java ecosystem’s evolution.