JRuby is an implementation of the
Ruby programming language atop the
Java Virtual Machine
A Java virtual machine (JVM) is a virtual machine that enables a computer to run Java programs as well as programs written in other languages that are also compiled to Java bytecode. The JVM is detailed by a specification that formally describes ...
, written largely in
Java
Java (; id, Jawa, ; jv, ꦗꦮ; su, ) is one of the Greater Sunda Islands in Indonesia. It is bordered by the Indian Ocean to the south and the Java Sea to the north. With a population of 151.6 million people, Java is the world's List ...
. It is
free software
Free software or libre software is computer software distributed under terms that allow users to run the software for any purpose as well as to study, change, and distribute it and any adapted versions. Free software is a matter of liberty, no ...
released under a three-way
EPL/
GPL
The GNU General Public License (GNU GPL or simply GPL) is a series of widely used free software licenses that guarantee end users the four freedoms to run, study, share, and modify the software. The license was the first copyleft for general us ...
/
LGPL
The GNU Lesser General Public License (LGPL) is a free-software license published by the Free Software Foundation (FSF). The license allows developers and companies to use and integrate a software component released under the LGPL into their own ...
license. JRuby is tightly integrated with
Java
Java (; id, Jawa, ; jv, ꦗꦮ; su, ) is one of the Greater Sunda Islands in Indonesia. It is bordered by the Indian Ocean to the south and the Java Sea to the north. With a population of 151.6 million people, Java is the world's List ...
to allow the embedding of the interpreter into any Java application with full two-way access between the Java and the Ruby code (similar to
Jython
Jython is an implementation of the Python programming language designed to run on the Java platform. The implementation was formerly known as JPython until 1999.
Overview
Jython programs can import and use any Java class. Except for some standa ...
for the Python language).
JRuby's lead developers are
Charles Oliver Nutter
Charles is a masculine given name predominantly found in English and French speaking countries. It is from the French form ''Charles'' of the Proto-Germanic name (in runic alphabet) or ''*karilaz'' (in Latin alphabet), whose meaning was "f ...
and
Thomas Enebo
Thomas may refer to:
People
* List of people with given name Thomas
* Thomas (name)
* Thomas (surname)
* Saint Thomas (disambiguation)
* Thomas Aquinas (1225–1274) Italian Dominican friar, philosopher, and Doctor of the Church
* Thomas the Ap ...
, with many current and past contributors including
Ola Bini
Ola Bini, (born Ola Martin Gustafsson in 1982) is a Swedish programmer and Internet activist, working for the Digital Autonomy Center in Ecuador on issues of privacy, security and cryptography. He has been in Ecuador since 2013.
In April 2019 B ...
and
Nick Sieger
Nick may refer to:
* Nick (given name)
* A cricket term for a slight deviation of the ball off the edge of the bat
* British slang for being arrested
* British slang for a police station
* British slang for stealing
* Short for nickname
Places ...
. In September 2006,
Sun Microsystems
Sun Microsystems, Inc. (Sun for short) was an American technology company that sold computers, computer components, software, and information technology services and created the Java programming language, the Solaris operating system, ZFS, the ...
hired Enebo and Nutter to work on JRuby full-time. In June 2007,
ThoughtWorks hired Ola Bini to work on Ruby and JRuby.
In July 2009, the JRuby developers left Sun to continue JRuby development at
Engine Yard
Engine Yard is a San Francisco, California based, privately held platform as a service company focused on Ruby on Rails, PHP and Node.js deployment and management.
History
Engine Yard, founded in 2006, offers a cloud application management platf ...
.
In May 2012, Nutter and Enebo left Engine Yard to work on JRuby at
Red Hat
Red Hat, Inc. is an American software company that provides open source software products to enterprises. Founded in 1993, Red Hat has its corporate headquarters in Raleigh, North Carolina, with other offices worldwide.
Red Hat has become ass ...
.
History
JRuby was originally created by Jan Arne Petersen, in 2001. At that time and for several years following, the code was a direct port of the Ruby 1.6
C code. With the release of Ruby 1.8.6, an effort began to update JRuby to 1.8.6 features and semantics. Since 2001, several contributors have assisted the project, leading to the current () core team of around six members.
JRuby 1.1 added
Just-in-time compilation and
Ahead-of-time compilation
In computer science, ahead-of-time compilation (AOT compilation) is the act of compiling an (often) higher-level programming language into an (often) lower-level language before execution of a program, usually at build-time, to reduce the amount ...
modes to JRuby and was already faster in most cases than the then-current Ruby 1.8.7 reference implementation.
JRuby packages are available for most platforms;
Fedora 9 was among the first to include it as a standard package at JRuby 1.1.1.
In July 2009, the core JRuby developers at Sun Microsystems,
Charles Oliver Nutter
Charles is a masculine given name predominantly found in English and French speaking countries. It is from the French form ''Charles'' of the Proto-Germanic name (in runic alphabet) or ''*karilaz'' (in Latin alphabet), whose meaning was "f ...
,
Thomas Enebo
Thomas may refer to:
People
* List of people with given name Thomas
* Thomas (name)
* Thomas (surname)
* Saint Thomas (disambiguation)
* Thomas Aquinas (1225–1274) Italian Dominican friar, philosopher, and Doctor of the Church
* Thomas the Ap ...
and
Nick Sieger
Nick may refer to:
* Nick (given name)
* A cricket term for a slight deviation of the ball off the edge of the bat
* British slang for being arrested
* British slang for a police station
* British slang for stealing
* Short for nickname
Places ...
, joined
Engine Yard
Engine Yard is a San Francisco, California based, privately held platform as a service company focused on Ruby on Rails, PHP and Node.js deployment and management.
History
Engine Yard, founded in 2006, offers a cloud application management platf ...
to continue JRuby development.
In May 2012, Nutter and Enebo left Engine Yard to work on JRuby at
Red Hat
Red Hat, Inc. is an American software company that provides open source software products to enterprises. Founded in 1993, Red Hat has its corporate headquarters in Raleigh, North Carolina, with other offices worldwide.
Red Hat has become ass ...
.
JRuby has supported compatibility with
Ruby MRI
Matz's Ruby Interpreter or Ruby MRI (also called CRuby) was the reference implementation of the Ruby programming language named after Ruby creator Yukihiro Matsumoto ("Matz"). Until the specification of the Ruby language in 2011, the MRI impleme ...
versions 1.6 through 1.9.3. JRuby 1.0 supported Ruby 1.8.6, with JRuby 1.4.0 updating that compatibility to Ruby 1.8.7. JRuby 1.6.0 added simultaneous support for Ruby 1.9.2, with JRuby 1.7.0 making Ruby 1.9.3 the default execution mode (Ruby 1.8.7 compatibility is available via a command-line flag). JRuby 9.0.0.0 added support for Ruby 2.2.
The current version of JRuby (9.4.0.0) supports Ruby 3.1.x
Ruby on Rails
JRuby has been able to run the
Ruby on Rails
Ruby on Rails (simplified as Rails) is a server-side web application framework written in Ruby under the MIT License. Rails is a model–view–controller (MVC) framework, providing default structures for a database, a web service, and web p ...
web framework since version 0.9 (May 2006),
with the ability to execute
RubyGems
RubyGems is a package manager for the Ruby programming language that provides a standard format for distributing Ruby programs and libraries (in a self-contained format called a "gem"), a tool designed to easily manage the installation of gems ...
and
WEBrick
WEBrick is a Ruby library providing simple HTTP web servers. It uses basic access authentication and digest access authentication for different kinds of servers that it can create - HTTP based server, HTTPS server, proxy server and virtual-host s ...
. Since the hiring of the two lead developers by Sun, Rails compatibility and speed have improved greatly. JRuby version 1.0 successfully passed nearly all of Rails's own test cases. Since then, developers have begun to use JRuby for Rails applications in production environments.
Multiple virtual machine collaboration
On February 27, 2008,
Sun Microsystems
Sun Microsystems, Inc. (Sun for short) was an American technology company that sold computers, computer components, software, and information technology services and created the Java programming language, the Solaris operating system, ZFS, the ...
and the
University of Tokyo announced a joint-research project to implement a virtual machine capable of executing more than one
Ruby
A ruby is a pinkish red to blood-red colored gemstone, a variety of the mineral corundum ( aluminium oxide). Ruby is one of the most popular traditional jewelry gems and is very durable. Other varieties of gem-quality corundum are called sa ...
or JRuby application on one interpreter.
Dynamic invocation on Java Virtual Machines
JSR 292
The Da Vinci Machine, also called the Multi Language Virtual Machine, was a Sun Microsystems project aiming to prototype the extension of the Java Virtual Machine (JVM) to add support for dynamic languages.
It was already possible to run dynam ...
(''Supporting Dynamically Typed Languages on the JavaTM Platform'') proposes:
* adding a new
invokedynamic
instruction at the JVM level, allowing method invocation using dynamic
type checking,
* dynamically changing classes and methods at runtime.
The Sun Open source project
Multi Language Virtual Machine aims to prototype this JSR. The first working prototype, developed as a patch on
OpenJDK, was announced and made available on end of August 2008.
The JRuby team has implemented dynamic invocation into their codebase. Dynamic invocation initially shipped with the 1.1.5 release in a primitive form. Version 1.7.0 enabled it by default on Java 8 builds.
Release history
This table presents only releases that present significant steps in JRuby history, aside from versions that mainly fixed bugs and improved performance. Performance improvements are also not shown in the table below, as every release has usually brought such improvements.
Design
Since early 2006, the current JRuby core team has endeavored to move JRuby beyond being a simple C port, to support better performance and to aid eventual compilation to
Java bytecode
In computing, Java bytecode is the bytecode-structured instruction set of the Java virtual machine (JVM), a virtual machine that enables a computer to run programs written in the Java programming language and several other programming languages, ...
. To support this end, the team set an ambitious goal: to be able to run Ruby on Rails unmodified using JRuby. In the process of achieving this goal, the JRuby test suite expanded to such extent that the team gained confidence in the "correctness" of JRuby. As a result, toward the end of 2006 and in the beginning of 2007, they began to commit much more complicated redesigns and refactorings of JRuby's core subsystems.
JRuby is designed to work as a mixed-mode virtual machine for Ruby, where code can be either interpreted directly, just-in-time compiled at runtime to Java bytecode, or ahead-of-time compiled to Java bytecode before execution. Until October 2007, only the
interpreted mode supported all Ruby's constructs, but a full AOT/JIT compiler is available since version 1.1.
The compiler design allows for interpreted and compiled code to run side-by-side, as well as
decompilation
A decompiler is a computer program that translates an executable file to a high-level source file which can be recompiled successfully. It does therefore the opposite of a typical compiler, which translates a high-level language to a low-level lan ...
to reoptimize and outputting generated bytecode as Java class files.
Frameworks support
JRuby has built-in support for Rails, RSpec,
Rake
Rake may refer to:
* Rake (stock character), a man habituated to immoral conduct
* Rake (theatre), the artificial slope of a theatre stage
Science and technology
* Rake receiver, a radio receiver
* Rake (geology), the angle between a feature on a ...
, and RubyGems. It embeds an FFI subsystem to allow the use of C libraries bundled as gems. It also allows launching the
Interactive Ruby Shell (irb) as Ruby MRI does.
The
Netbeans Ruby Pack, available in NetBeans 6, allows IDE development with Ruby and JRuby, as well as Ruby on Rails for the two implementations of Ruby.
It is no longer included in NetBeans 7.0 and later.
Programming
Ruby meets Java
JRuby is similar to the standard Ruby interpreter except written in
Java
Java (; id, Jawa, ; jv, ꦗꦮ; su, ) is one of the Greater Sunda Islands in Indonesia. It is bordered by the Indian Ocean to the south and the Java Sea to the north. With a population of 151.6 million people, Java is the world's List ...
. JRuby features some of the same concepts, including
object-oriented programming
Object-oriented programming (OOP) is a programming paradigm based on the concept of "objects", which can contain data and code. The data is in the form of fields (often known as attributes or ''properties''), and the code is in the form of pr ...
, and
dynamic typing as Ruby. The key difference is that JRuby is tightly integrated with Java, and can be called directly from Java programs. Java has significant footing in the development of web applications.
JRuby calling Java
One powerful feature of JRuby is its ability to invoke the classes of the
Java Platform. To do this, one must first load JRuby's Java support, by calling "require 'java'". The following example creates a Java JFrame with a JLabel:
require 'java'
frame = javax.swing.JFrame.new
frame.getContentPane.add javax.swing.JLabel.new('Hello, World!')
frame.setDefaultCloseOperation javax.swing.JFrame::EXIT_ON_CLOSE
frame.pack
frame.set_visible true
JRuby also allows the user to call Java code using the more Ruby-like
underscore method naming and to refer to
JavaBean
In computing based on the Java Platform, JavaBeans is a technology developed by Sun Microsystems and released in 1996, as part of JDK 1.1.
The 'beans' of JavaBeans are classes that encapsulate one or more objects into a single standardized objec ...
properties as attributes:
frame.content_pane.add label
frame.visible = true
Calling JRuby from Java
JRuby can just as easily be called from Java, using either the
JSR 223 Scripting for Java 6 or the
Apache Bean Scripting framework.
//Example using JSR 233 Scripting for Java 6
ScriptEngineManager mgr = new ScriptEngineManager();
ScriptEngine rbEngine = mgr.getEngineByExtension("rb");
try catch (ScriptException ex)
Performance
According to some benchmarks, JRuby is faster than alternatives. Since implementations vary in how much code is loaded before execution, different methods of measuring speed can lead to biased interpretations of performance advantages. The time it takes for a
Java Virtual Machine
A Java virtual machine (JVM) is a virtual machine that enables a computer to run Java programs as well as programs written in other languages that are also compiled to Java bytecode. The JVM is detailed by a specification that formally describes ...
itself to load is often excluded from execution times when calculating benchmarks.
JRuby has the significant architectural advantage to be able to leverage JVM threads without being constrained by a
global interpreter lock (similarly to
Rubinius), therefore achieving full parallelism within a process, which Ruby MRI cannot achieve despite leveraging OS threads.
In a real
Mongrel web server
A web server is computer software and underlying hardware that accepts requests via HTTP (the network protocol created to distribute web content) or its secure variant HTTPS. A user agent, commonly a web browser or web crawler, initiate ...
application tested in 2007, JRuby performance is better than Ruby MRI 1.8, after the Java Virtual Machine had been instantiated.
In a 2007 benchmark of Ruby implementations, JRuby was faster than Ruby MRI 1.8 in some tests, but
YARV
YARV (Yet another Ruby VM) is a bytecode interpreter that was developed for the Ruby programming language by Koichi Sasada. The goal of the project was to greatly reduce the execution time of Ruby programs.
Since YARV has become the official Ru ...
outperformed both of them.
As of April 2014, in
The Computer Language Benchmarks Game, JRuby 1.7.4 typically has the same performance as Ruby MRI 2.1.0, but uses more memory.
See also
*
GraalVM
GraalVM is a Java VM and JDK based on HotSpot/OpenJDK, implemented in Java. It supports additional programming languages and execution modes, like ahead-of-time compilation of Java applications for fast startup and low memory footprint. The fi ...
*
List of Java scripting languages
*
ZK (framework)
ZK is an open-source Ajax Web application framework, written in Java, that enables creation of graphical user interfaces for Web applications with little required programming knowledge.
The core of ZK consists of an Ajax-based event-driven mecha ...
– an Ajax framework supporting JRuby
References
Further reading
*
*
*
*
*
External links
*
{{DEFAULTSORT:Jruby
Free software programmed in Java (programming language)
Free software programmed in Ruby
JVM programming languages
Object-oriented programming languages
Ruby (programming language)
Scripting languages
Software using the Eclipse license