Summary

Print-friendly Version

[Contents]

You now have the DemoBean example working and you have sucessfully run the client. If so, then you should now also have some feel for the required parts of an Enterprise JavaBeans application, and how easy it is to create real distributed multitier applications.

Basic Recipe

An important thing to notice is that while the design and implementation of a "real" application might take a lot more time, and involve far more complex logic to model the business, the recipe is basically the same. The Java programmer follows the steps of specifying the interfaces, remote, home, and so on, and then writing the logic in the bean, as per the example recipe.

What You Didn't Do

In Enterprise Java beans much of the strength of the model comes from what the programmer does not have to do, for instance Java programmers no longer have to learn CORBA IDL, nor do they have to handle multithreading issues. Indeed explicit creation of threads by the Enterprise JavaBeans programmer is illegal in any Enterprise JavaBeans-compliant container/server--this is the function of the server/container vendor. Other things the Enterprise JavaBeans programmer does not have to code include: security issues (these are declared in the DeploymentDescriptor), anything to do with the underlying protocol, and anything that is platform-specific.

Next Steps

While simple examples are good to learn on, they can also be annoying in what they don't cover. Specifically not covered in this example is any type of database access. Hence security and transactional issues are well highlighted, although as stated above there is little application programming to be done for these. Also in both stateful-session beans, and entity beans there is a little more work to do to utilise the "state" kept on the server, and this is not highlighted.

One final point is that sophisticated tools for Enterprise JavaBeans development are on their way from many of Sun's partners, and much of the work done by hand in creating and declaring of interfaces and so on, will become much simpler, for example, as simple as clicking a button!

In Conclusion

It is hoped this introduction has helped you to see the strengths of the Enterprise JavaBeans model, and whether you are a seasoned CORBA, Perl, or even VB programmer, it is hoped you will start to see just how easy and powerful Enterprise JavaBeans can be!

About the Authors

Tom Daly and Uday Shetty work in Market Development engineering at Sun. Tom Daly has a background in Enterprise systems management and performance testing and has been working with Java technology since the alpha 0.3 release. Uday Shetty has been working for some time with application servers.

Click here to return to the Enterprise JavaBeans Tutorial Index page.