Overview of Java 12 New Features

Java 12 introduced several enhancements and new features designed to improve the performance, usability, and capabilities of the language. Below is a structured overview of the main features explained in a clear and beginner-friendly manner.

1. Switch Expressions (Preview)

• Feature: Switch statements can now be used as expressions, allowing them to return a value.
• Benefit: This change makes the code more concise and readable.
• Example:

int day = 4;
String dayName = switch(day) {
    case 1 -> "Monday";
    case 2 -> "Tuesday";
    case 3 -> "Wednesday";
    case 4 -> "Thursday";
    case 5 -> "Friday";
    case 6 -> "Saturday";
    case 7 -> "Sunday";
    default -> throw new IllegalArgumentException("Invalid day: " + day);
};

2. JEP 189: Shenandoah Garbage Collector (Experimental)

• Feature: A new low-pause-time garbage collector aimed at reducing pause times in applications.
• Benefit: It helps maintain application responsiveness.
• Note: This feature is experimental and may not be suitable for all applications.

3. JEP 230: Microbenchmark Suite

• Feature: A suite for accurately benchmarking Java code to measure performance.
• Benefit: Helps developers optimize their code by providing precise performance measurements.

4. JEP 341: Default CDS Archives

• Feature: Class Data Sharing (CDS) now includes default archives for faster application startup.
• Benefit: This leads to improved performance in the startup time of Java applications.

5. Other Features and Enhancements

• Example:
• New Collectors.teeing() method: This method allows combining results of two collectors.
• JEP 344: Abortable Mixed Collections: Enhances the garbage collection process by allowing mixed collections to be aborted.

String Methods: New methods like String::isBlank() and String::lines() were added to enhance string manipulation.

String str = "   ";
System.out.println(str.isBlank()); // true

Conclusion

Java 12 brought significant improvements that enhance performance and developer productivity through new features and optimizations. Beginners should focus on understanding the new switch expressions and string methods, as these can simplify code and make it more efficient.