JSR-241: Groovy – A New Standard Programming Language for the Java Platform
JSR-241: The Groovy Programming Language proposes the standardization of a new programming language for the Java Platform – one that is on equal footing with the Java programming language. Groovy is an agile, dynamic programming language like Python, Perl and Ruby, but it's designed specifically for the Java Platform and is completely interoperable with conventional Java programs. Groovy is not a replacement for the Java programming language; it’s a complement to that language. It fills a niche that is in demand by developers but is currently neglected by the Java Platform.
Until now the Java programming language has reigned supreme as the standard programming language for the Java Platform. It has served us well for close to nine years, but it cannot be all things to all people. And it shouldn't. The Java Programming language, like C++ and C#, is a strongly and statically typed programming language. While this type of language, sometimes called a "conventional" language, is useful for solving many problems, it is not a panacea. Conventional programming languages are very exacting, meaning that you have to dot every 'i' and cross every 't' in order for the program to compile. This orthography of statically defining all the types may result in more predictable code, but it also tends to slow developers down.
An alternative to conventional programming languages are agile programming languages like Python, Ruby and Perl among others. These agile languages have long been called "scripting" languages, but that term is not, IMO, sufficient. Many in IT perceive scripting languages as layman languages that sacrifice technical sophistication for easy of use. This may be true of some scripting languages, but it's certainly not the case with Python, Ruby or Perl. These are dynamic and powerful programming languages that happen to use less syntax to accomplish more.
To be perfectly honest, although I'm listed on the JSR as a co-spec lead, I'm a Johnny-come-lately to the Groovy bandwagon. Groovy already has a grass roots following and all the credit for the development of Groovy goes James Strachan and other contributors to the Groovy open source project. I'm not a language designer, but I understand the power that languages like Python and Ruby offer developers and I believe it is time for the Java Platform to include an agile programming language. It's this personal conviction that led me to initiate and co-develop JSR-241 with James Strachan and Gier Magnusson of Apache. My role as a specification lead is to manage the progression of this JSR through the JCP and author the Groovy Language Specification – two tasks that can be terribly distracting to those doing the really hard work of developing the JSR itself.
Groovy represents the beginning of a new era in the Java platform, one in which the Java community embraces language diversification and harnesses the full potential of the Java platform. It’s the recognition that the Java is more than a programming language; it’s a robust platform upon which multiple languages can operate and co-exist. To me this has always been the unrealized promise of the Java Platform.
The Java programming language is, simply put, a convenient abstraction for the real language of the Java platform: byte code. As a user-friendly abstraction for byte code the Java programming language is powerful, but it's not omnipotent. There are circumstances in which a different language, an agile programming language, is more expressive and productive.
So why Groovy? Why not Jython or JRuby? Why not one of the dozens of other programming languages that are designed to run on the Java Virtual Machine? It's my opinion, and I believe the opinion of those who support this JSR, that Groovy is the best choice because it was built from the ground up for the Java Platform and uses syntax that is familiar to Java developers, while leveraging some of best features that Python, Ruby and Smalltalk have to offer. Jython and JRuby are excellent examples of how existing languages can be ported to the Java platform, but they are, after all, ports. They use syntax that is not designed with Java developers in mind and they are founded on a completely different set of code libraries. Groovy is designed for Java developers and its foundation is the standard APIs of the Java Platform.