Java 20 Features: Complete Guide to New Capabilities

Introduction

Java 20 brings significant improvements and new features to enhance developer productivity and application performance.

Key Features Overview

Record Patterns (Second Preview)

This feature enhances the Java programming language with record patterns to deconstruct record values. Record patterns and type patterns can be nested to enable a powerful, declarative, and composable form of data navigation and processing.

Pattern Matching for Switch Statements and Expressions (Fourth Preview)

This feature extends pattern matching to express more sophisticated, composable data queries in switch statements and expressions.

Foreign Function and Memory API (Second Preview)

This API introduces an API by which Java programs can interoperate with code and data outside of the Java runtime.

Scoped Values (Incubator)

This feature introduces scoped values, which enable the sharing of immutable data within and across threads.

Virtual Threads

A game-changing feature for concurrent programming:

  • Lightweight thread implementation
  • Improved scalability
  • Better resource utilization

Vector API (Proposal)

This API provides a high-performance, efficient way to operate on arrays of primitive data types.

Unicode 15.0 Support

This release includes support for Unicode 15.0, which includes new characters and emoji.

Improved Control of G1 Concurrent Refinement Threads

This release includes improvements to the G1 garbage collector, which can improve the performance of concurrent applications.

Support for CLDR Version 42

This release includes support for CLDR Version 42, which provides locale data for over 150 languages.

Migration Guide

  1. Preparation steps
  2. Compatibility considerations
  3. Best practices

Performance Improvements

More info