Both .NET and J2EE target the enormous market for enterprise applications and Web services. This quick-comparison provides a basic sense of advantages and disadvantages carried by both frameworks in various areas.
J2EE is Java-centric and platform neutral, while .NET is Windows-centric and language-neutral. This means developers are restricted to Java language in the J2EE and Windows in the .NET framework.
Difference in Strategies
J2EE is basically a series of standards. One the other hand, .NET is Microsoft's product strategy based on evolution of its Visual Studio 6.0.
Sun has rallied the entire industry behind its J2EE standard, especially the top software vendors who have adapted the J2EE interface such as BEA, IBM, and Oracle. On the other hand, .NET is based on Microsoft's sole efforts to grab the Web services market share.
Legacy Integration and Backwards Compatibility
For J2EE program, it is easy to link with the legacy code through the use of adapters and Sun's new Java Connector Architecture (JCA) specification. .NET as well offers legacy integration with its Host Integration Server 2000, but with limited connectivity to select systems. In sum, experts feel that the J2EE legacy integration features are superior to those found in .NET, since the JCA market is building a huge marketplace of adapters to ease up enterprise application integration.
As far as backwards integration is concerned, in the case of .NET, the introduction of Common Language Runtime (CLR) and the increased object-oriented structure of VB.NET lay down serious obstacles for the code written in VB 6.0 or earlier versions to be upgraded to VB.NET, according to experts.
Rapid Application Development
Both .NET and J2EE offer rapid application deployment features in their own way. Some are more powerful in .NET compared with J2EE and vice versa. J2EE offers state management services to ease up developers on writing code and managing state. On the other hand, the real advantage behind ASP.NET is that it is independent of client device and allows for user interfaces to be rendered to alternative user interfaces without rewriting code. In addition to this, Microsoft .NET offers Queued Components and business process management and E-commerce capabilities which in many cases are superior to comparable features found n J2EE.
Pros and Cons of Single Vendor Solutions
J2EE offers solutions from multiple vendors with a wide variety of tools, products and applications. This does provide additional and varied functionality but at a cost: J2EE tools often times are not interoperable due to problems in portability. The reason is that they are not from a single vendor and not well-tested. Larger J2EE vendors do offer robust solutions, but for low-level J2EE implementation one has to undergo rigorous homework of mixing and matching for a complete solution. On the other hand, .NET provides a complete solution of tools and services from Microsoft, but which may lack some of the higher-end features found in J2EE solutions.
J2EE exists today and operates on mission-critical systems where large J2EE vendors such as BEA, Borland, Sybase offer tried and tested solutions to their large customer base. J2EE does have certain aspects that are new and immature such as automatic persistence provided by EJB, Java Connector Architecture, and Web services support. In the case of Microsoft, some of the .NET is based on Windows DNA but most of it is rewritten as far as the new CLR is concerned. Moreover, C# language and Web services support is new and according to many testers, .NET VB is very different from the earlier VB version. Hence, we can say that in the overall sense J2EE is the more mature platform.
The Language Factor
Java programming language is at the center of J2EE. All components such as EJB and servlets that are deployed in J2EE framework are also written in Java. Although JVM byte code is language-neutral, but in practice this byte code can only be used with Java.
On the other hand, the .NET framework, based on the new CLR, enables development in any language that is supported by Microsoft's tools. The pro of this multi-language support is that a single .NET component can be written in several languages. As far as the con is concerned, first you need experts in different languages to fully develop, debug and maintain a particular application written in multiple languages. Second, this affects negatively on team productivity since this way, best practices are hard to be shared among knowledge workers. Third, it requires a significant cost in training and retaining knowledgeable developers.
In the case of J2EE, the aspect of standardization on a single language helps to avoid the problems discussed above. In conclusion, businesses need to carefully weigh various aspects of their decisions in choosing a Web services platform.
The Portability Factor
Since Java Runtime Environment (JRE) is available on any platform -- Win 32, Unix, Mainframe -- there is no doubt about easy and effective J2EE portability. The big industry vendors -- BEA, IBM, and Oracle -- along with other consulting firms and ISVs stand firm behind J2EE because it is the only framework that promises the most consulting support, ISV applications and Web services infrastructure.
In the .NET case, the portability aspect is not promising since industry analysts are skeptical of Microsoft's claims regarding Multiple platform support based on the company's lackluster performance in meeting industry expectations.
Web Services Support
J2EE enables eBusiness collaboration and Web services through its JAXP (Java API for XML Parsing). Additional convenience APIs are also under development to help developers perform Web services. Also, various J2EE-compatible 3rd party tools are available to enable rapid Web services deployment.
.NET does create Web services but due to its beta release it does not earn much credibility as a realistic deployment platform. Moreover, .NET's lack of support for ebXML poses a real problem for its industry-wide acceptability. ebXML is fast becoming an important international standard for eBusiness collaboration and the problem with Microsoft is that it still depends on its own BizTalk proprietary framework that bears proprietary SOAP extensions.
Current IDEs for Java development include WebGain's Visual Cafe, IBM's VisualAge for Java, Borland's JBuilder, etc. Also, a variety of 3rd party tools and open source-code products are available. Although the functionality of the toolset provided by the J2EE community exceeds those provided by Microsoft, these tools are not entirely interoperable because they do not originate from a single vendor.
On the other hand, Microsoft's Visual Studio .NET has remarkable productivity features that include Web forms, .NET's GUI component set, and much more. The aspect of single-vendor integration, wizards, and other user-friendly features are highly advantageous for building Web services.
The Role of Shared Context
The vision of shared context suggests users don't need to type in their user names and passwords every time while using Web services. Both J2EE and .NET support shared context with their relative pros and cons. J2EE proponents envision a marketplace of shared context repositories on the Web to ensure specialization in various industry areas for better serving different customer needs such as customers for banking and finance, medical history information, etc. This approach, according to market players is scalable and more secure in handling needs of the masses.
.NET, on the other hand, presents a single shared context repository approach based on its Hailstorm services. This framework offers a user-centric Web service experience and one place to find identity information. The industry is skeptical of this approach in the context of security maintenance and dominance of a single entity over identity data of individual and businesses.
Both .NET and J2EE support Win32 platform, a less expensive alternative to Unix and Mainframe systems. In general, Microsoft's solution has an aggressive price comparative to J2EE that offers varied price and service levels from high-end to low-end inexpensive solutions.
Performance and Developer Empowerment
J2EE is an ideal platform for educated and knowledgeable developers to leverage the programming control over lower-level services such as state management and caching. In comparison, .NET architecture lacks lower-level performance improvement services, blocks introduction of errors into the system and is thus more suitable for developers who require more hand-holding.