Project Amber

The goal of Project Amber is to explore and incubate smaller, productivity-oriented Java language features that have been accepted as candidate JEPs in the OpenJDK JEP Process. This Project is sponsored by the Compiler Group.

Most Project Amber features go through at least two rounds of preview before becoming an official part of the Java Platform. For a given feature, there are separate JEPs for each round of preview and for final standardization.

Status of JEPs

Currently in progress:

468: Derived Record Creation (Preview)

Currently in preview:

495: Simple Source Files and Instance Main Methods (Fourth Preview) (previous: 445, 463, 477)
494: Module Import Declarations (Second Preview) (previous: 476)
492: Flexible Constructor Bodies (Third Preview) (previous: 447, 482)
488: Primitive Types in Patterns, instanceof, and switch (Second Preview) (previous: 455)

Delivered:

458: Launch Multi-File Source-Code Programs
456: Unnamed Variables and Patterns (preview: 433)
441: Pattern Matching for switch (previews: 406, 420, 427, 433)
440: Record Patterns (previews: 405, 432)
409: Sealed Classes (previews: 360, 397)
395: Records (previews: 359, 384)
394: Pattern Matching for instanceof (previews: 305, 375)
378: Text Blocks (previews: 355, 368)
- Programmer’s Guide
361: Switch Expressions (previews: 325, 354)
323: Local-Variable Syntax for Lambda Parameters
286: Local-Variable Type Inference (var)
- Style Guidelines
- FAQ

On hold:

301: Enhanced Enums (see here for explanation)
302: Lambda Leftovers
348: Java Compiler Intrinsics for JDK APIs

Withdrawn:

465: String Templates (Third Preview) (see here for explanation)
326: Raw String Literals, dropped in favor of Text Blocks (see here for explanation)

Documents

Guides
- Local Variable Type Inference Style Guide (March 2018)
- Local Variable Type Inference FAQ (Oct 2018)
- Programmer’s Guide to Text Blocks (Aug 2019)
Design notes
- Symbolic References for Constants (March 2018)
- Data Classes and Sealed Types for Java (February 2019)
- Towards Better Serialization (June 2019)
- Pattern matching
  - Pattern Matching for Java (September 2018)
  - Pattern Matching in the Java Object Model (December 2020)
  - Pattern Matching for Java — Semantics (August 2020)
  - Pattern Matching for Java — Runtime and Translation (June 2017)
  - Extending switch for Pattern Matching (April 2017)
  - Type Patterns in switch (September 2020)
  - Patterns: Exhaustiveness, Unconditionality, and Remainder (May 2023)
  - Towards Member Patterns (January 2024)
- String Tapas Redux: Beyond Mere String Interpolation (September 2021)
Historical notes
- Data Classes for Java (October 2017)
- Data Classes for Java (February 2018)

Community

Members
Mailing Lists
- amber-dev — For technical discussion related to Project Amber
- amber-spec-experts — For Expert Group members only
- amber-spec-observers — A read-only clone of amber-spec-experts
- amber-spec-comments — For submitting comments on the official specs
Other Resources
- Inside.java
- Dev.java