This document discusses how Java and the OpenJDK project have moved towards a more agile development process over time. It describes how the JDK Enhancement Proposal process was introduced in JDK 8 to allow for smaller pieces of work than a full Java Specification Request. This has enabled more frequent delivery of new features in point releases like JDK 8 and 9. However, integrating new APIs while maintaining compatibility with the specification and test compatibility kit remains a challenge. The document concludes that while Java has made progress in becoming more agile and open-source driven, challenges around standards and testing remain.

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© Copyright Azul Systems 2015
@speakjava
Is An Agile Standard
For Java Possible?
Simon Ritter
Deputy CTO, Azul Systems
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Waterfall vs. Agile
Requirements/Design/Implement/Test
Agile
iteration 1
Agile
iteration 2
Agile
iteration 3
Agile
iteration n
Waterfall
Agile

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Agile Manifesto Applied To Java
1. Satisfy the customer through early and continuous delivery
of valuable software
2. Welcome changing requirements, even late in development
3. Deliver working software frequently
7. Working software is the measure of progress
8. Agile processes promote sustainable development
10. Continuous attention to technical excelllence and good
design enhances agility

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1995

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1997
Sun Microsystems sues Microsoft
over Java implementation in IE4

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1998

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1999

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JCP Golden Triangle
Specifications (JSRs)
Reference
Implementation (RI)
Technology
Compatibility Kit
(TCK)
Can you build it?
Is the spec.
unambiguous?
Does the RI conform to the spec?

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2005-2011
Apache Harmony

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2006
javac Hotspot

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2007
(Almost) all remaining code
OpenJDK 7 b53 (2009)
100% open source

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2007-2017: 10 Years Of OpenJDK

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OpenJDK Binary Distributions
Internal
only
Java SE
reference
implementation

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JDK 8
DocLint
Base64 Encoding/decoding
Streams API
Remove permgen
Lambdas Nashorn
Repeating annotations
Extension methods
Compact Profiles
Date and Time API
Optional
Annotations on types
Compact strings
Scalable update variables

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JDK 9
jlink
Enhanced deprecation
REPL: jshell
Stream enhancements
Modularity
Concurrency
updates
Variable Handles
Factory methods for Collections
Spin-Wait Hints
G1 Default Collector
Milling Project Coin
Better stack walking
Compact strings
Private methods in interfaces

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Making OpenJDK More Agile
 JDK Enhancement Proposals
 Introduced in JDK 8
– Smaller pieces of work than a full JSR
– Also covers things not covered by Java SE spec.
 JDK 8 had 56 JEPs (u20 had 2, u40 had 12, u60 had 2)
 JDK 9 has 89 JEPs
 Provides a roadmap
– Intended to extend at least 3 years into the future

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JEP 2.0 Process

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Issues
 Creating point releases is great
– New functionality delivered rapidly
 What about the spec?
 What about the TCK?
 How to build and ship conformant implementations?
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Incubator Modules (JEP 11)
 Develop APIs without making them part of the standard
– At least not straight away
 Allow developers to “kick the tyres”
– Not always possible to get a new API right first time
 Move from incubator to full module
– Becomes part of the standard
 JDK 9 only has one incubator: HTTP/2 (JEP 110)
 Some concerns about fragmentation
--do-not-resolve-by-default
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Summary
 Java has followed a winding road to open source and open
standards
 Developed through JCP and JDK Enhancement Proposals
– Not driven entirely by Oracle, community involvement
 Potentially the Java platform could become more agile
– This is not without its challenges
 Java will continue to be the world’s most popular
development platform
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© Copyright Azul Systems 2015
@speakjava
Thank You!
Simon Ritter
Deputy CTO, Azul Systems
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