What are the features introduced in Java 12?

Table of Contents

• Introduction
• Key Features of Java 12
  • 1. Switch Expressions (Preview)
  • 2. New Garbage Collector Options
  • 3. Compact Number Formatting
  • 4. Default CDS (Class Data Sharing)
  • 5. New API Features
  • 6. Improved Performance and JVM Enhancements
  • 7. Microbenchmark Suite
• Conclusion

Introduction

Java 12, released in March 2019, brought several notable features and enhancements aimed at improving the developer experience, performance, and code readability. These updates continue to evolve the Java language and platform, making it more efficient and user-friendly. This guide outlines the key features of Java 12 and their implications for developers.

Key Features of Java 12

1. Switch Expressions (Preview)

Java 12 introduced switch expressions as a preview feature, allowing developers to use the switch statement as an expression. This feature enhances code clarity and reduces boilerplate.

• Benefits:
  • Simplifies the syntax for handling multiple cases.
  • Allows the use of the yield keyword to return values from a switch expression.

Example:

2. New Garbage Collector Options

Java 12 introduced the Shenandoah garbage collector as an experimental feature. Shenandoah is designed for low-pause-time garbage collection, aiming to minimize GC pause times regardless of heap size.

• Benefits:
  • Provides a more predictable response time for applications.
  • Especially useful for applications with large heaps that require consistent performance.

3. Compact Number Formatting

Java 12 introduced a new API for compact number formatting, which allows developers to format numbers in a more user-friendly way (e.g., using "K" for thousands, "M" for millions).

Example:

4. Default CDS (Class Data Sharing)

Java 12 made Class Data Sharing (CDS) a default feature. CDS allows the JVM to preload classes into memory, improving startup time and reducing footprint.

• Benefits:
  • Faster application startup times.
  • Reduces memory usage by sharing common class metadata across Java applications.

5. New API Features

Java 12 introduced various API enhancements, including:

• **String::repeat(int)**: A new method to repeat a string a specified number of times.

Example:

6. Improved Performance and JVM Enhancements

Java 12 included several performance improvements and optimizations in the JVM, including:

• Enhancements to the performance of the JIT compiler.
• Improvements in overall application throughput.

7. Microbenchmark Suite

Java 12 included a microbenchmark suite that provides tools for performance testing. This helps developers benchmark their code and understand performance characteristics.

Conclusion

Java 12 introduced a variety of features aimed at enhancing the language, improving performance, and providing developers with new tools for writing efficient code. Key updates like switch expressions and compact number formatting contribute to cleaner and more expressive code. The addition of new garbage collector options and API enhancements continues to improve the overall performance and usability of Java applications. Understanding these features can help developers leverage Java 12 effectively in their projects.