Edited By Gregory Brill
The Java language is an extremely popular, object-oriented programming language originally released by Sun Microsystems in 1995. Over the past eight years, its user base (and fan base) has grown steadily due to its simplicity and robustness, and it can be found everywhere from professional software development companies to businesses to high school and college classrooms.
With the release of .NET, Microsoft’s new framework for Windows software development, Microsoft has created an opportunity for Java developers to use the language they know and yet take full advantage of the Microsoft Visual Studio .NET Integrated Development Environment (VS .NET), which we will discuss later in this chapter. For the moment, you can think of Visual Studio .NET as a language-neutral development environment that assists you in writing code in any one of a number of languages. Regardless of the language you choose, VS .NET will ultimately compile your code into a universal language called Microsoft Intermediate Language (MSIL). MSIL is very similar in principle to Java bytecode. However, MSIL has additional benefits in terms of crosslanguage development.
J# (pronounced jay-sharp) is the newest language to be supported by the Visual Studio .NET environment and is essentially Java for the .NET Framework. Not only does J# allow Java developers to program comfortably within the Microsoft integrated development environment (IDE), it also allows them to take full advantage of the extensive libraries and capabilities inherent in the .NET Framework. Like any .NET language, J# can be used to write ASP.NET Web Applications (Active Server Pages .NET, covered in Chapter 5) applications, XML Web Services (Chapter 6), ADO.NET data applications (Chapter 8), and a host of other .NET target types. Keep in mind that the J# compiler understands the Java language, but ultimately compiles it to MSIL (instead of the bytecode you may be used to). Thus, the front end is Java, but the compiled results run on the Microsoft .NET Framework, as opposed to a Java Virtual Machine (JVM). We will look at the similarities and differences between the Java language and the .NET Framework later in this chapter.