J-Integra® for .NET Documentation

Introduction

J-Integra® for .NET™ is a unique bridge between the world of Java™ and the world of Microsoft® .NET. Both of these technologies will be at the forefront of enterprise development over the next few years. This means that every medium-to-large company is likely to have systems running .NET and Java. J-Integra® for .NET offers such enterprise companies the ability to tightly integrate these two technologies in a convenient and reliable fashion.

J-Integra® for .NET will give your company the power to:

• Write clients for Enterprise Java Beans (EJBs) in any language supported by the .NET Common Language Runtime (CLR).
• Access .NET components from any type of Java object.
• Mix and match your Web server technologies with your other middleware technologies. For example, use ASP.NET together with EJBs or Java servlets together with .NET components.
• Cleanly integrate two of the top leading technologies in your environment, without re-writing any code. Every medium-to-large business is likely to have Java and .NET technologies existing side by side.
• Maximize reuse of your components. With J-Integra For .NET, components written in one technology can be reused in other technologies.
• Increase the market size for your product by making your Java products accessible from .NET, or vice versa.
• Leverage the existing skill base of your workforce. Move to Java technology on the server while still using your Windows programmers for client side software without retraining.

How Does it Work?

J-Integra® for .NET leverages .NET Remoting, Microsoft's new distributed object protocol. .NET Remoting combines the best of the newer distributed technologies - Web services - with the best of the older distributed technologies such as DCOM, CORBA and RMI. .NET Remoting is designed to be used in a tightly-coupled intranet environment, where previously COM/CORBA or RMI was used, or in a loosely-coupled Internet environment.

.NET Remoting is used to enable CLR-based components in different application domains to talk to each other. It is important to remember that the CLR supports many different languages including C#, Visual Basic.NET, ASP.NET and C++. Using J-Integra® for .NET, Java components appear to be CLR components, and CLR components appear to be Java components.

One of the most interesting features of .NET Remoting is that the transport protocol and the data formatting are configurable and extendable. Currently .NET and J-Integra® for .NET support both HTTP and TCP/IP transport protocols, and binary data formatting. These are the defaults that come with .NET Remoting.

Advantages vs. Web Services

Web Services is a revolutionary new technology that is specifically designed for businesses to provide services and exchange information over the Internet. While .NET Remoting is not an industry-wide standard, it does have the following advantages over Web Services which are especially relevant in an intranet environment:

• Multiple protocol support including high-speed binary over TCP - faster than SOAP over HTTP
• Support for activation and lifetime control of remote objects by the client (similar to DCOM)
• Support for passing objects by reference and by value.
• Support for callbacks
• Support for additional context information specific to .NET. In the future, such information will enable additional features such as distributed transactions and additional security levels.
• Guaranteed interoperability
• Support for events
• Support for type system fidelity, which means that there is a one-to-one mapping between the class and type hierarchy. Web services and SOAP do not support such an object-oriented mechanism for accessing remote objects.

Because J-Integra® for .NET uses .NET Remoting it also has these advantages over Web services.

Examples of Using J-Integra® for .NET

The following examples illustrate how easy it is to use J-Integra For .NET.

Accessing an Internet Information Server (IIS) Component from Java

The GenJava tool generates the Java proxies for the .NET component:

The Janetor tool configures the J-Integra® for .NET runtime. Details such as the URL of the CLR component can be specified here:

Java clients can use the generated proxies and access the remote CLR component as if it were a local Java component:

Accessing an EJB from .Net

The GenNet tool generates a .NET component containing proxies for the EJB client-side classes.

Janetor generates a Web Application archive (WAR) file containing all the files to be deployed in the Web server.

The WAR file can be then easily deployed in any Web server supporting servlets. The CLR client, which can be written in one of many different languages, can access the EJBs as if it were accessing local CLR components.

Getting Started

To get general overview of the different J-Integra® for .NET components and the roles they play, see Overview of the J-Integra® for .NET Components.

For a full listing of all examples, click on the Contents button to show the navigation panel, and expand the Examples node.