Welcome!

Weblogic Authors: Yeshim Deniz, Elizabeth White, Michael Meiner, Michael Bushong, Avi Rosenthal

Related Topics: Weblogic

Weblogic: Article

CMP 2.0, EJBGen, and Builder Make EJBs Easy!

CMP 2.0, EJBGen, and Builder Make EJBs Easy!

EJBs have always been the best way to ensure that your applications were portable and would leverage all the optimizations of the J2EE server. Now they are also easy to build. With the release of WebLogic Platform 7.0, you can create EJBs in record time. At the center of this revolution is Container Managed Persistence 2.0, which allows WebLogic to build tools that remove the layers from EJB development. Relations, the standard EJB query language, and JavaBean-like properties all contribute to this new age. Since EJB 1.0 was introduced it's had a rap as a difficult, complex technology to implement - probably for good reason. This release of WebLogic is targeted at changing that. Going forward there will be more and more tools to help you develop EJBs painlessly and efficiently.

The biggest tool for the developer is EJBGen. EJBGen gives you the power to create an entire EJB, including home and remote (and/or local) interfaces and deployment descriptors, by creating a single implementation file marked up with special JavaDoc tags. This drastically increases the maintainability of the system and makes it simple for developers to quickly generate the EJBs needed for a project. Listing 1 demonstrates this for you.

The relatively small amount of source code and description translates directly into all the pieces that make up an EJB component JAR. To generate the code, simply use EJBGen, which runs as a JavaDoc doclet:

javadoc -doclet weblogic.tools.ejbgen.EJBGen -d targetDir FooEJB.java

In the targetDir you'll find the Java source and the deployment descriptors for all the components that make up your EJB. Compile and JAR the files to deploy to the server. It's really as simple as that.

WebLogic Builder is the biggest time-saving tool if you've already written your EJBs and just need to configure and deploy them. The Builder tool will crack open .jar, .ear, and .war files or work on open directory structures to configure the deployment descriptors for all your components. Not only that, using an internal tool called DDInit (we provide Ant tasks to run it outside the Builder), you can take loose classes and turn them into components.

Let's say you don't want to use EJBGen or are given a set of interfaces for the EJB. Simply write the implementation beans compile, and point the Builder at your directory. Not only will it discover what kinds of beans you have, it will also generate defaults for all the deployment descriptors, including all the relations between beans. It's that simple. With a bean that is mostly for data, you can get away with writing as little as a couple of interfaces and one abstract implementation class with no methods!

There are also a couple of tools in the works that can save you time. Expect to see SQL2EJB and ReverseEJBGen in a follow-on release. SQL2EJB does what you might imagine: given a database with a reasonable schema (it's best if it has all of its foreign and primary keys properly marked), it will generate a set of EJBGen source classes that can then be EJBGen'd, compiled, and deployed to a server. Even better, since WebLogic supports dynamic table creation, you can deploy it to another database that doesn't already have the schema for testing or development purposes. This is the type of tool that has only become reasonable with the introduction of relations to the EJB specification. ReverseEJBGen does what you might imagine: given an EJB component, or set of components, it will generate an EJBGen source file that includes all the information found in the deployment descriptors. It will consolidate all those disparate files down to one file that is the final word on an EJB. Also, it lets you use the Builder tool to edit a deployed EJBGen'd component, change the deployment descriptors, and then convert back to the original format.

Expect to see these types of tools integrated with products like WebLogic Builder to make developing products for the WebLogic Platform as simple as possible.

More Stories By Sam Pullara

Sam Pullara has been a software engineer at WebLogic since 1996 and has contributed to the architecture, design, and implementation of many aspects of the application server.

e-mail: [email protected]

Comments (0)

Share your thoughts on this story.

Add your comment
You must be signed in to add a comment. Sign-in | Register

In accordance with our Comment Policy, we encourage comments that are on topic, relevant and to-the-point. We will remove comments that include profanity, personal attacks, racial slurs, threats of violence, or other inappropriate material that violates our Terms and Conditions, and will block users who make repeated violations. We ask all readers to expect diversity of opinion and to treat one another with dignity and respect.


IoT & Smart Cities Stories
The challenges of aggregating data from consumer-oriented devices, such as wearable technologies and smart thermostats, are fairly well-understood. However, there are a new set of challenges for IoT devices that generate megabytes or gigabytes of data per second. Certainly, the infrastructure will have to change, as those volumes of data will likely overwhelm the available bandwidth for aggregating the data into a central repository. Ochandarena discusses a whole new way to think about your next...
CloudEXPO | DevOpsSUMMIT | DXWorldEXPO are the world's most influential, independent events where Cloud Computing was coined and where technology buyers and vendors meet to experience and discuss the big picture of Digital Transformation and all of the strategies, tactics, and tools they need to realize their goals. Sponsors of DXWorldEXPO | CloudEXPO benefit from unmatched branding, profile building and lead generation opportunities.
All in Mobile is a place where we continually maximize their impact by fostering understanding, empathy, insights, creativity and joy. They believe that a truly useful and desirable mobile app doesn't need the brightest idea or the most advanced technology. A great product begins with understanding people. It's easy to think that customers will love your app, but can you justify it? They make sure your final app is something that users truly want and need. The only way to do this is by ...
Digital Transformation and Disruption, Amazon Style - What You Can Learn. Chris Kocher is a co-founder of Grey Heron, a management and strategic marketing consulting firm. He has 25+ years in both strategic and hands-on operating experience helping executives and investors build revenues and shareholder value. He has consulted with over 130 companies on innovating with new business models, product strategies and monetization. Chris has held management positions at HP and Symantec in addition to ...
DXWorldEXPO LLC announced today that Big Data Federation to Exhibit at the 22nd International CloudEXPO, colocated with DevOpsSUMMIT and DXWorldEXPO, November 12-13, 2018 in New York City. Big Data Federation, Inc. develops and applies artificial intelligence to predict financial and economic events that matter. The company uncovers patterns and precise drivers of performance and outcomes with the aid of machine-learning algorithms, big data, and fundamental analysis. Their products are deployed...
Dynatrace is an application performance management software company with products for the information technology departments and digital business owners of medium and large businesses. Building the Future of Monitoring with Artificial Intelligence. Today we can collect lots and lots of performance data. We build beautiful dashboards and even have fancy query languages to access and transform the data. Still performance data is a secret language only a couple of people understand. The more busine...
Cell networks have the advantage of long-range communications, reaching an estimated 90% of the world. But cell networks such as 2G, 3G and LTE consume lots of power and were designed for connecting people. They are not optimized for low- or battery-powered devices or for IoT applications with infrequently transmitted data. Cell IoT modules that support narrow-band IoT and 4G cell networks will enable cell connectivity, device management, and app enablement for low-power wide-area network IoT. B...
The hierarchical architecture that distributes "compute" within the network specially at the edge can enable new services by harnessing emerging technologies. But Edge-Compute comes at increased cost that needs to be managed and potentially augmented by creative architecture solutions as there will always a catching-up with the capacity demands. Processing power in smartphones has enhanced YoY and there is increasingly spare compute capacity that can be potentially pooled. Uber has successfully ...
SYS-CON Events announced today that CrowdReviews.com has been named “Media Sponsor” of SYS-CON's 22nd International Cloud Expo, which will take place on June 5–7, 2018, at the Javits Center in New York City, NY. CrowdReviews.com is a transparent online platform for determining which products and services are the best based on the opinion of the crowd. The crowd consists of Internet users that have experienced products and services first-hand and have an interest in letting other potential buye...
When talking IoT we often focus on the devices, the sensors, the hardware itself. The new smart appliances, the new smart or self-driving cars (which are amalgamations of many ‘things'). When we are looking at the world of IoT, we should take a step back, look at the big picture. What value are these devices providing. IoT is not about the devices, its about the data consumed and generated. The devices are tools, mechanisms, conduits. This paper discusses the considerations when dealing with the...