CS2J : C# to Java conversion tool

Introduction

CS2J is the most advanced C# to Java conversion tool available today.

• CS2J produces good looking, maintainable Java software from your C# source code.
• It uses a powerful, extensible template system to translate .NET Framework and 3rd party library calls.
• It is a command-line tool which can be easily incorporated into your existing development workflow.
• And it is completely Open Source!

CS2J was initially developed by Rustici Software to translate their SCORM Engine web application (http://www.scorm.com), it was later developed and marketed by Twiglet Software as a general purpose C# to Java application translator. We are now pleased to be able to make the source code freely available.

The CS2J source distribution has two components:

• CSharpTranslator:

  This builds the cs2j.exe executable. This executable runs directly under Windows and under Mono on other platforms (http://www.mono-project.com/Main_Page).

  This work is licensed under the MIT / X Window System License (http://opensource.org/licenses/mit-license.php).

  With this license the produced Java code is completely unencumbered and you can do what you want with it.

• CS2JLibrary:

  This contains the XML translation files that direct cs2j to translate .Net framework calls into appropriate Java code, and the CS2JLibrary Java support library that should be deployed with translated applications.

  Note that the XML folder is now in CSharpTranslator directory, and part of the Visual Studio project.

  This work is licensed under the Apache License, Version 2.0 (http://www.apache.org/licenses/LICENSE-2.0).

How it works

The way CS2J translate your C# application can be sliced in 4 parts :

• The creation of an environment based on XML translation files and your C# application. This environment allows CS2J to make links between your classes, and the transformations to perform. This work is done by TemlateExtracter.

Then for each file.cs:

• JavaMaker parses the file and creates a first AST (Abstract Syntax Tree)
• NetMaker parses the first tree, convert most of .NET call into its Java equivalent and create a second AST
• JavaPrettyPrint parses the second tree, finalizes the translation, and creates a human readable code which will be saved into file.java.

How to modify a translation / add your own

As was said before, translations are, for the biggest part, done using XML. To modify / add some content, you should modify the XML, but it is awful to modify huge files, and worse to create your own. That's why Ijinus created an edition tool : CS2JXmlEditor.

We recommend you to use this tool in order to respect the XML schema definition (which is at the moment not the case of all the XML).