Welcome!

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

Related Topics: Weblogic

Weblogic: Article

Effective EJB: Make EJBs Work For You

"Java Development is at a Crossroads."

Java development is at a crossroads. The open standards have done lot of good for the Java platform and language, but they have brought in some problems too. Developers are often drenched in the complexities that surround Java development. Worse yet, these complexities are so overwhelming that the actual business problems take a back seat.

The J2EE specification provides a lot of APIs, standards, and open ends that allow architects, designers, and developers to build superior enterprise systems. Care must be taken to engage in the balancing act of choosing the right technology.

Technology development has created more confusion for the developers (unless developers are versatile) rather than helping them to resolve the issues. Often, architects and developers spend most of their time supporting their chosen framework instead of concentrating on the business problem in hand.

This article discusses the techniques involved in designing and developing superior J2EE applications using the Enterprise Java Beans (EJB) specification. While the article does not intend to show how to use EJB, I'll discuss the various pitfalls in EJB development and essentially focus on the real-world antipatterns that sneak into your development.

Learning things the hard way is nice, but due to the ever-shortening development cycles, it is smarter to learn from mistakes made by other people. Having a comprehensive understanding of where the dangers are will help one to take a proactive strategy, which is precisely the theme of this article. We will start with the EJB Context in J2EE applications and then discuss some potential dangers that exist in EJB development.

Effective EJB Decision
Software is an engineered art and the engineering is continuous. With each exciting technology such as the EJB specification, weary engineering minds tend to adopt the exciting new technology in hurry. This is one reason most EJB projects fail. Often they fail so badly that they finish at point of no return. It would be wiser to engineer the choice of EJB rather than to embrace it just because it's a hot, sexy, and promising technology.

With regard to component architecture for building distributed, transactional, and persistent business solutions, the decision to use EJB in software projects demands a careful analysis and proactive planning with sound engineering practices.

Choosing Unwisely (A Golden Hammer for a Fly)
"When you have a hammer in your hand, everything looks a nail." This phrase befits most EJB choices. EJB may not be the best suited for most projects simply because the following are true:

  • You have already paid for the server and have an EJB container ready for use
  • You are doing enterprise Java development (is your business really an enterprise?)
  • You want a fully portable architecture (is EJB really portable?)
  • You have a container and EJB allows you to delegate most of the jobs to the container (this would reduce the development cost/time and ensure fast time to market)
Solution (Choose Wisely)
Figure 1 shows the trade-off between project size and cost for a simple POJO (Plain Old Java Objects) solution and an EJB solution.

Choosing an EJB Solution

  • Strive to achieve the break-even point quickly
  • Choose EJB if your project is complex (as seen in the graph, EJB projects start complex and expensive, but ramp up more slowly with project size)
  • Choose EJB if the services provided the EJB container are needed for the business; in other words, choose EJB if the answer is YES to the following questions:
    - Do your components need to be distributed?
    - Do you need to handle global transactions?
    - Do you have security requirements at the business-component level?
    - Do you need a persistence framework that rund inside a managed environment?
    - Does your application need high scalability?
Not Everything Is an EJB
The most often seen misinterpretation of EJB among junior- and intermediate-level users is that when you use EJB, every component is an EJB.

No. This is rarely true. A component or a subsystem may be a true EJB candidate while others can be just POJOs. This mixed-mode design is tough, but engineering the design decisions at each component/subsystem level makes life easier during the roll out.

Coarse-Grained and Fine-Grained Services
One key aspect of choosing EJB at the subsystem level is to understand the EJB services. EJB components come in two flavors: a set of work horse components called session beans and a set of persistence components called entity beans. Session beans are generally coarse-grained services that take advantage of a container's ability to provide distribution, transaction management, and security. For a non-EJB component, the implementation of these services is the developer's responsibility. Components that make heavy use of these services are often the right candidates for session EJBs.

The EJB specification mandates support for fine-grained persistence services through entity beans. Each entity bean can itself be again distributed, transaction aware, and secure and hence there is a complex mixture of fine-grained and coarse-grained services. Often, this mixture makes entity bean components very difficult to manage. If a component needs to be just persistent, there is seldom a need for the component to be an EJB. Other popular, lightweight persistence frameworks exist (e.g., JDO, Hibernate etc.) that are easier to maintain.

Effective EJB Interfaces
One of the key aspects of EJB design is creating interfaces. Interfaces are the lingua franca of the EJB components. They serve as a vehicle to expose the services provided by the EJB component to the external world. Poor interface design would lead to EJBs that are hard to maintain and change.

Considerations for Interface Design
What is the size of your network pipe? At the end of the day, EJB is RMI. It involves remote procedure calls. The location transparency will just add some more network complexity. The EJB calls involve significant marshalling and unmarshalling of parameters over the network. Care should be taken when designing the remote interfaces. If you have a big pipe and can stream large data quickly through it, then the interfaces can be coarse grained. On the other hand, if you have a smaller bandwidth, then you're probably better off having finer-grained interfaces and lightweight parameter marshalling.

More Stories By Shankar Itchapurapu

Shankar Itchapurapu is a software engineer at Oracle in India. He holds a Master's degree in Computer Applications. You can e-mail Shankar at [email protected]

Comments (3) View Comments

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.


Most Recent Comments
shankar 12/15/05 06:34:12 AM EST

test

shankar 12/15/05 06:34:01 AM EST

test

Java Developer's Journal News Desk 10/17/05 01:27:02 PM EDT

Effective EJB. Java development is at a crossroads. The open standards have done lot of good for the Java platform and language, but they have brought in some problems too. Developers are often drenched in the complexities that surround Java development. Worse yet, these complexities are so overwhelming that the actual business problems take a back seat.

@ThingsExpo Stories
DX World EXPO, LLC, a Lighthouse Point, Florida-based startup trade show producer and the creator of "DXWorldEXPO® - Digital Transformation Conference & Expo" has announced its executive management team. The team is headed by Levent Selamoglu, who has been named CEO. "Now is the time for a truly global DX event, to bring together the leading minds from the technology world in a conversation about Digital Transformation," he said in making the announcement.
"Space Monkey by Vivent Smart Home is a product that is a distributed cloud-based edge storage network. Vivent Smart Home, our parent company, is a smart home provider that places a lot of hard drives across homes in North America," explained JT Olds, Director of Engineering, and Brandon Crowfeather, Product Manager, at Vivint Smart Home, in this SYS-CON.tv interview at @ThingsExpo, held Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA.
SYS-CON Events announced today that Conference Guru has been named “Media Sponsor” of the 22nd International Cloud Expo, which will take place on June 5-7, 2018, at the Javits Center in New York, NY. A valuable conference experience generates new contacts, sales leads, potential strategic partners and potential investors; helps gather competitive intelligence and even provides inspiration for new products and services. Conference Guru works with conference organizers to pass great deals to gre...
The Internet of Things will challenge the status quo of how IT and development organizations operate. Or will it? Certainly the fog layer of IoT requires special insights about data ontology, security and transactional integrity. But the developmental challenges are the same: People, Process and Platform. In his session at @ThingsExpo, Craig Sproule, CEO of Metavine, demonstrated how to move beyond today's coding paradigm and shared the must-have mindsets for removing complexity from the develop...
In his Opening Keynote at 21st Cloud Expo, John Considine, General Manager of IBM Cloud Infrastructure, led attendees through the exciting evolution of the cloud. He looked at this major disruption from the perspective of technology, business models, and what this means for enterprises of all sizes. John Considine is General Manager of Cloud Infrastructure Services at IBM. In that role he is responsible for leading IBM’s public cloud infrastructure including strategy, development, and offering m...
"Evatronix provides design services to companies that need to integrate the IoT technology in their products but they don't necessarily have the expertise, knowledge and design team to do so," explained Adam Morawiec, VP of Business Development at Evatronix, in this SYS-CON.tv interview at @ThingsExpo, held Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA.
To get the most out of their data, successful companies are not focusing on queries and data lakes, they are actively integrating analytics into their operations with a data-first application development approach. Real-time adjustments to improve revenues, reduce costs, or mitigate risk rely on applications that minimize latency on a variety of data sources. In his session at @BigDataExpo, Jack Norris, Senior Vice President, Data and Applications at MapR Technologies, reviewed best practices to ...
Widespread fragmentation is stalling the growth of the IIoT and making it difficult for partners to work together. The number of software platforms, apps, hardware and connectivity standards is creating paralysis among businesses that are afraid of being locked into a solution. EdgeX Foundry is unifying the community around a common IoT edge framework and an ecosystem of interoperable components.
Large industrial manufacturing organizations are adopting the agile principles of cloud software companies. The industrial manufacturing development process has not scaled over time. Now that design CAD teams are geographically distributed, centralizing their work is key. With large multi-gigabyte projects, outdated tools have stifled industrial team agility, time-to-market milestones, and impacted P&L stakeholders.
"Akvelon is a software development company and we also provide consultancy services to folks who are looking to scale or accelerate their engineering roadmaps," explained Jeremiah Mothersell, Marketing Manager at Akvelon, in this SYS-CON.tv interview at 21st Cloud Expo, held Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA.
"IBM is really all in on blockchain. We take a look at sort of the history of blockchain ledger technologies. It started out with bitcoin, Ethereum, and IBM evaluated these particular blockchain technologies and found they were anonymous and permissionless and that many companies were looking for permissioned blockchain," stated René Bostic, Technical VP of the IBM Cloud Unit in North America, in this SYS-CON.tv interview at 21st Cloud Expo, held Oct 31 – Nov 2, 2017, at the Santa Clara Conventi...
In his session at 21st Cloud Expo, Carl J. Levine, Senior Technical Evangelist for NS1, will objectively discuss how DNS is used to solve Digital Transformation challenges in large SaaS applications, CDNs, AdTech platforms, and other demanding use cases. Carl J. Levine is the Senior Technical Evangelist for NS1. A veteran of the Internet Infrastructure space, he has over a decade of experience with startups, networking protocols and Internet infrastructure, combined with the unique ability to it...
22nd International Cloud Expo, taking place June 5-7, 2018, at the Javits Center in New York City, NY, and co-located with the 1st DXWorld Expo will feature technical sessions from a rock star conference faculty and the leading industry players in the world. Cloud computing is now being embraced by a majority of enterprises of all sizes. Yesterday's debate about public vs. private has transformed into the reality of hybrid cloud: a recent survey shows that 74% of enterprises have a hybrid cloud ...
"Cloud Academy is an enterprise training platform for the cloud, specifically public clouds. We offer guided learning experiences on AWS, Azure, Google Cloud and all the surrounding methodologies and technologies that you need to know and your teams need to know in order to leverage the full benefits of the cloud," explained Alex Brower, VP of Marketing at Cloud Academy, in this SYS-CON.tv interview at 21st Cloud Expo, held Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clar...
Gemini is Yahoo’s native and search advertising platform. To ensure the quality of a complex distributed system that spans multiple products and components and across various desktop websites and mobile app and web experiences – both Yahoo owned and operated and third-party syndication (supply), with complex interaction with more than a billion users and numerous advertisers globally (demand) – it becomes imperative to automate a set of end-to-end tests 24x7 to detect bugs and regression. In th...
"MobiDev is a software development company and we do complex, custom software development for everybody from entrepreneurs to large enterprises," explained Alan Winters, U.S. Head of Business Development at MobiDev, in this SYS-CON.tv interview at 21st Cloud Expo, held Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA.
Coca-Cola’s Google powered digital signage system lays the groundwork for a more valuable connection between Coke and its customers. Digital signs pair software with high-resolution displays so that a message can be changed instantly based on what the operator wants to communicate or sell. In their Day 3 Keynote at 21st Cloud Expo, Greg Chambers, Global Group Director, Digital Innovation, Coca-Cola, and Vidya Nagarajan, a Senior Product Manager at Google, discussed how from store operations and ...
"There's plenty of bandwidth out there but it's never in the right place. So what Cedexis does is uses data to work out the best pathways to get data from the origin to the person who wants to get it," explained Simon Jones, Evangelist and Head of Marketing at Cedexis, in this SYS-CON.tv interview at 21st Cloud Expo, held Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA.
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...
SYS-CON Events announced today that Telecom Reseller 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, NY. Telecom Reseller reports on Unified Communications, UCaaS, BPaaS for enterprise and SMBs. They report extensively on both customer premises based solutions such as IP-PBX as well as cloud based and hosted platforms.