JSR

About

A Java Specification Request (JSR) is a formal proposal submitted to define a new standard or enhancement to the Java platform. It is part of the Java Community Process (JCP) — the official process by which the Java language, libraries, and technologies evolve.

Each JSR is a document that describes proposed specifications, APIs, or features intended to be incorporated into the Java platform. A JSR can range from a minor library enhancement to the definition of an entirely new Java technology.

Why JSRs Exist ?

• Standardization: JSRs ensure that Java APIs and technologies evolve in a consistent, predictable, and open manner.

• Interoperability: By following standardized specifications, Java applications and libraries are more likely to be interoperable across vendors and platforms.

• Community Collaboration: JSRs allow the global Java community (including developers, vendors, and academia) to contribute to the growth of the platform through expert input.

• Backward Compatibility: JSRs often include guidelines to maintain compatibility with older versions of Java, helping the ecosystem stay stable.

Who Manages JSRs?

JSRs are managed by the Java Community Process (JCP), a formalized mechanism introduced by Sun Microsystems (now part of Oracle).

• The JCP Executive Committee oversees the process.

• Each JSR is led by one or more Spec Leads, often from large Java-centric organizations (e.g., Oracle, Red Hat, IBM).

• Expert Groups are formed to collaboratively draft and refine the specifications.

Structure of a JSR

A JSR typically contains:

• Specification Document: The formal written standard describing the API, behavior, and semantics.

• Reference Implementation (RI): A working implementation that conforms to the specification, demonstrating its viability.

• Technology Compatibility Kit (TCK): A suite of tests that verifies whether an implementation adheres to the specification.

Every JSR must provide both the RI and TCK to be considered complete.

JSR Lifecycle

1. JSR Submission A spec lead submits a proposal to the JCP Executive Committee.

2. Review Period The proposal undergoes community review for comments and feedback.

3. Expert Group Formation Approved JSRs form an expert group composed of members from the Java community.

4. Early Draft Review A preliminary draft is shared with the public for comments.

5. Public Review and Ballots The specification is reviewed multiple times and voted on by the Executive Committee.

6. Proposed Final Draft The final draft is created, including the RI and TCK.

7. Final Approval Ballot The final JSR is voted on. Upon approval, it becomes an official part of the Java platform.

8. Maintenance and Revisions JSRs can be updated via Maintenance Releases to fix issues or make enhancements.

Categories of JSRs

JSRs can apply to various editions of the Java platform:

• Java SE (Standard Edition): Core Java libraries, language enhancements, and JVM improvements.

• Java EE (Enterprise Edition): APIs for enterprise-level applications like Servlets, JPA, JMS, etc.

• Java ME (Micro Edition): Specifications for embedded and mobile devices.

• JavaFX (discontinued under JSR but once defined UI components and behavior for rich clients).

Examples of Important JSRs

Here are some widely adopted and influential JSRs:

Java SE (Core)

• JSR 269 – Pluggable Annotation Processing API Defines how annotation processors are invoked during compilation.

• JSR 292 – Supporting Dynamically Typed Languages on the JVM Introduced the invokedynamic instruction, aiding performance for dynamic languages like Groovy and Kotlin.

• JSR 335 – Lambda Expressions for the Java Programming Language Introduced lambdas and the Stream API in Java 8.

Java EE (Enterprise)

• JSR 315 – Java Servlet 3.0 Specification Modernized Servlets to support asynchronous processing.

• JSR 338 – Java Persistence API (JPA) 2.1 Standardized object-relational mapping (ORM) in Java.

• JSR 370 – JAX-RS 2.1: The Java API for RESTful Web Services Defined standard APIs for building RESTful services.

Recent Platform-wide Specifications

• JSR 376 – Java Platform Module System (JPMS) Introduced modularity to the Java platform in Java 9.

• JSR 388 – Java SE 13 Platform Specification Updated the Java SE platform with new features and APIs.

How JSRs Impact Developers and the Industry ?

Benefits for Developers

• Reliable APIs: Developers can depend on consistent, tested APIs.

• Ecosystem Compatibility: Applications and libraries that implement or use JSR-compliant components are likely to be interoperable.

• Future-Proofing: Since JSRs often evolve with backward compatibility, software built on JSRs remains relevant across multiple Java versions.

Benefits for Vendors

• Certification: Vendors can build tools and environments (e.g., application servers) that are JSR-compliant, giving assurance to clients.

• Credibility: Following a recognized standard ensures higher market trust.

How JSRs Differ from Other Standards (Like ISO) ?

Aspect	JSR	ISO
Scope	Java Platform (language, libraries, APIs)	Broad (global standards across industries)
Governing Body	Java Community Process (JCP)	International Organization for Standardization
Participation	Open to Java community (experts, vendors, developers)	Representatives from national standards bodies
Focus	Language-specific innovations and consistency	Industry-wide best practices and protocols
Implementation	Reference Implementation + TCK mandatory	May or may not require implementation