Visual J#
ParadigmObject-oriented, structured, imperative
First appearedJuly 1, 2002; 21 years ago (2002-07-01)
Final release
v2.0 Second Edition / 18 May 2007; 16 years ago (2007-05-18)
Platform.NET Framework
Influenced by
Java and Visual J++

Visual J# (pronounced "jay-sharp") is a discontinued implementation of the J# programming language that was a transitional language for programmers of Java and Visual J++ languages, so they could use their existing knowledge and applications with the .NET Framework.[1][2] It was introduced in 2002[3] and discontinued in 2007, with support for the final release of the product continuing until October 2017.

J# worked with Java bytecode as well as source so it could be used to transition applications that used third-party libraries, even if their original source code was unavailable.[citation needed] It was developed by the Hyderabad-based Microsoft India Development Center at HITEC City in India.[4][5]

The implementation of Java in Visual J++, MSJVM, did not pass Sun's compliance tests leading to a lawsuit from Sun, Java's creator, and creation of J#. Microsoft ceased such support for the MSJVM on December 31, 2007 (later Oracle bought Sun, and with it Java and its trademarks). Microsoft however, officially started distributing Java again in 2021 (though not bundled with Windows or its web browsers as before with J++), i.e. their build of Oracle's OpenJDK,[6] which Microsoft plans to support for at least 6 years, for LTS versions, i.e. to September 2027 for Java 17.

Fundamental differences between J# and Java

Java and J# use the same general syntax but there are non-Java conventions in J# to support the .NET environment. For example, to use .NET "properties" with a standard JavaBean class, it is necessary to prefix getter and setter methods with the Javadoc-like annotation:

	/** @beanproperty	 */

…and change the corresponding private variable name to be different from the suffix of the getXxx/setXxx names[citation needed].

J# does not compile Java-language source code to Java bytecode (.class files), and does not support Java applet development or the ability to host applets directly in a web browser, although it does provide a wrapper called Microsoft J# Browser Controls for hosting them as ActiveX objects. Finally, Java Native Interface (JNI) and raw native interface (RNI) are substituted with P/Invoke; J# does not support remote method invocation (RMI).[7]

InfoWorld said: "J#'s interface to the .NET framework is solid, but not as seamless as C#. In particular, J# code cannot define new .NET attributes, events, value types, or delegates. J# can make use of these language constructs if they are defined in an assembly written in another language, but its inability to define new ones limits J#'s reach and interoperability compared to other .NET languages."[8]

Contrariwise, Microsoft documentation for Visual Studio 2005 details the definition of .NET delegates,[9] events,[10] and value types[11] directly in J#.

History of J#

In January 2007, Microsoft announced:[12]

The download of Visual J# 2005 Express Edition is no longer available from Microsoft's website.

Visual J# is out of support including the Visual J# 2.0 Redistributable Second Edition released in 2007, that was supported through to 2017 "(5 years mainstream and 5 years extended support) on EN-US locales."[15][16]

See also


  1. ^ "Visual J# Home". Retrieved 2017-03-24.
  2. ^ "Java to .NET Framework Migration Workshop: Free Online Training". Archived from the original on 2008-04-23. Retrieved 2020-01-28.((cite web)): CS1 maint: bot: original URL status unknown (link)
  3. ^ Microsoft News, [1], 1 July 2002
  4. ^ S Prasanna, Microsoft's VJ#.Net is made in India, Express Computer, 29 July 2002 Archived 28 November 2013 at the Wayback Machine
  5. ^ "The Hindu Business Line : Microsoft lines up big plans for Hyderabad centre".
  6. ^ "Announcing General Availability of Microsoft Build of OpenJDK". Java at Microsoft. 2021-05-25. Retrieved 2021-08-03.
  7. ^ "Visual J# Migration". Visual Studio 2005. MSDN Library. Archived from the original on 2012-03-16. Retrieved 2021-12-25.
  8. ^ Yager, Tom (21 November 2001). "Just don't call J# Java". InfoWorld. Retrieved 2020-07-20.
  9. ^ "delegate (Visual J#)". Visual Studio 2005. MSDN Library. Archived from the original on 2011-12-19.
  10. ^ "Definition and Use of Events". Visual Studio 2005. MSDN Library. Archived from the original on 2011-12-19.
  11. ^ "User-Defined Value Types". Visual Studio 2005. MSDN Library. Archived from the original on 2011-12-20.
  12. ^ Microsoft Developer Network, Visual J# Product Announcement, 10 January 2007
  13. ^ "Visual J# 2.0 Second Edition Redistributable Download". Microsoft. Archived from the original on 2007-05-23. Retrieved 2010-04-27.((cite web)): CS1 maint: bot: original URL status unknown (link)
  14. ^ "Calling J# code from .NET 4.0 - Windward Wrocks". Retrieved 6 March 2017.
  15. ^ "Visual J# Home". Retrieved 6 March 2017.
  16. ^ "End of Support for Visual Studio 2008 – in One Year". Retrieved 2017-04-11.