Welcome!

Machine Learning Authors: Pat Romanski, Liz McMillan, Yeshim Deniz, Elizabeth White, Corey Roth

Related Topics: Java IoT

Java IoT: Article

An Introduction to EJBs With Lots of Code

An Introduction to EJBs With Lots of Code

This was actually the first book on Enterprise JavaBeans that came into the market. Enterprise JavaBeans was released in June and made its debut at JavaOne this year. This is a pretty good book for developers who like to see a lot of code. The examples in the book are used to develop a fairly complex application and the code isn't meant for novices. Tom Valesky presents many examples. I like the fact that the book takes an example and builds its complexity in successive chapters. There's good coverage of distributed architectures and transactions. The author has also dedicated a chapter to provide some excellent guidelines for building distributed systems. For readers just starting out in distributed applications, the author provides the appropriate background. This book isn't for everyone, though. Readers already familiar with distributed systems and transactions may not want to go through the tutorial style followed in the book and may find the detailed code discussions irritating.

The book is written in an easy, informal, tutorial style. It's well organized and easy to follow. In some places the discussion becomes pretty terse, so you may want to take a few breaks when reading. My suggestion to readers who go out and purchase this book: get the software for running the code, install it and then read the book. Test out the examples and read the book in sequence.

Chapters 1 and 2 focus on introducing the reader to the concepts that form the basis of this book. The first chapter provides an excellent discussion on the evolution of computer architectures from the single-tier mainframe model to the n-tier distributed architecture. In this discussion the author also covers the basics of distributed transaction processing. The chapter ends by showing how Enterprise JavaBeans fit into the big picture. A brief introduction to the EJB spec is provided. Chapter 2 discusses the Enterprise JavaBeans architecture.

The concepts are explained well, with the right level of detail. It makes a good stand-alone chapter for reading without requiring the reader to read the rest of the book. The author introduces the appropriate number of class methods to give an overview without confusing the reader. The code is developed using WebLogic and EJBHome software packages.

Chapters 3-6 focus on the various types of EJB development. These chapters follow a pattern: an introduction to the concept, followed by design choice for the example, then a detailed discussion of the example as it is built in parts. It concludes with an analysis of what goes on behind the scenes. As mentioned earlier, a tutorial style is followed, with Chapter 3 focusing primarily on creating a simple client for a "hello, world" example. The design, implementation and deployment of software are explained in detailed, concise steps. The last section of this chapter summarizes what really went on behind the scenes as the reader developed this example. This is again typical of the author's tutorial style. Chapter 4 provides a good overview of session beans. The example in this chapter successfully brings out the main features and functionality offered by session beans. It also discusses transactions vis-ˆ-vis EJBs. An online shopping example is developed using stateful session beans, followed by an example using stateless session beans. The next chapter (Chapter 5) discusses entity beans and persistence management in EJBs. The examples offered in this chapter reuse code from the previous chapter to illustrate design with container-managed persistence as well as bean-managed persistence.

Chapter 6 deals with the topic of developing EJB clients. The author purposely deferred discussions on writing the client till this chapter. Instead of implementing a complicated client, he gives examples of "small" single-purpose clients that bring out different points he's trying to make.

This makes the code and the discussion very easy to follow. The example gets a little long, but is appropriate at this stage. Chapter 7 goes into some depth about a few necessary but pretty boring parts of the EJB spec: deployment. The author does a good job of providing the requisite information for the reader to get a handle on this topic. The chapter ends with a discussion on deployment issues that developers may face such as caching and persistence. The author also provides a set of guidelines for developers to follow when dealing with EJB containers.

Chapter 8 is a unique chapter that shows the author's grasp of distributed systems. It encapsulates a lot of hard-won technical experience, which is useful to the developer of distributed systems. This is a rare and valuable commodity. Guidelines on transaction design, business logic design, databases, testing and application design are provided in concise discussions.

Chapter 9 sums up all the concepts in the book by walking the reader through a complex example. The "time tracker" example is well picked. It uses the major features from the EJB spec in a real-world system. It demonstrates the use of both session and entity beans. There is also a session bean (TimeTrackerBean) that in turn uses an entity bean (EmployeeBean). The design is well explained. This chapter is useful since it's hard to find an example that illustrates the different aspects of EJBs. Most tutorial classes fail to provide such examples. This chapter alone makes the book worth buying. Chapter 10 briefly talks about existing EJB vendors and future directions for EJB. Of course, you can compare the predictions with what has really happened since the book is a few months old. An Appendix carries complete code listings. These are also available in the accompanying CD.

In conclusion, this is a good book for programmers and developers who are trying to get an introduction to EJBs and like playing around with plenty of code. Enterprise JavaBeans: Developing Component-Based Distributed Applications by Thomas C. Valesky 352 pages, Addison Wesley.

More Stories By Ajit Sagar

Ajit Sagar is Associate VP, Digital Transformation Practice at Infosys Limited. A seasoned IT executive with 20+ years experience across various facts of the industry including consulting, business development, architecture and design he is architecture consulting and delivery lead for Infosys's Digital Transformation practice. He was also the Founding Editor of XML Journal and Chief Editor of Java Developer's Journal.

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.


@CloudExpo Stories
DXWorldEXPO LLC announced today that the upcoming DXWorldEXPO | CloudEXPO New York event will feature 10 companies from Poland to participate at the "Poland Digital Transformation Pavilion" on November 12-13, 2018.
Without a clear strategy for cost control and an architecture designed with cloud services in mind, costs and operational performance can quickly get out of control. To avoid multiple architectural redesigns requires extensive thought and planning. Boundary (now part of BMC) launched a new public-facing multi-tenant high resolution monitoring service on Amazon AWS two years ago, facing challenges and learning best practices in the early days of the new service.
Digital Transformation is much more than a buzzword. The radical shift to digital mechanisms for almost every process is evident across all industries and verticals. This is often especially true in financial services, where the legacy environment is many times unable to keep up with the rapidly shifting demands of the consumer. The constant pressure to provide complete, omnichannel delivery of customer-facing solutions to meet both regulatory and customer demands is putting enormous pressure on...
The best way to leverage your CloudEXPO | DXWorldEXPO presence as a sponsor and exhibitor is to plan your news announcements around our events. The press covering CloudEXPO | DXWorldEXPO will have access to these releases and will amplify your news announcements. More than two dozen Cloud companies either set deals at our shows or have announced their mergers and acquisitions at CloudEXPO. Product announcements during our show provide your company with the most reach through our targeted audienc...
With 10 simultaneous tracks, keynotes, general sessions and targeted breakout classes, @CloudEXPO and DXWorldEXPO are two of the most important technology events of the year. Since its launch over eight years ago, @CloudEXPO and DXWorldEXPO have presented a rock star faculty as well as showcased hundreds of sponsors and exhibitors!
In an era of historic innovation fueled by unprecedented access to data and technology, the low cost and risk of entering new markets has leveled the playing field for business. Today, any ambitious innovator can easily introduce a new application or product that can reinvent business models and transform the client experience. In their Day 2 Keynote at 19th Cloud Expo, Mercer Rowe, IBM Vice President of Strategic Alliances, and Raejeanne Skillern, Intel Vice President of Data Center Group and ...
More and more brands have jumped on the IoT bandwagon. We have an excess of wearables – activity trackers, smartwatches, smart glasses and sneakers, and more that track seemingly endless datapoints. However, most consumers have no idea what “IoT” means. Creating more wearables that track data shouldn't be the aim of brands; delivering meaningful, tangible relevance to their users should be. We're in a period in which the IoT pendulum is still swinging. Initially, it swung toward "smart for smart...
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...
DXWorldEXPO LLC announced today that All in Mobile, a mobile app development company from Poland, will exhibit at the 22nd International CloudEXPO | DXWorldEXPO. All In Mobile is a mobile app development company from Poland. Since 2014, they maintain passion for developing mobile applications for enterprises and startups worldwide.
@DevOpsSummit at Cloud Expo, taking place November 12-13 in New York City, NY, is co-located with 22nd international CloudEXPO | first international DXWorldEXPO and will feature technical sessions from a rock star conference faculty and the leading industry players in the world.
In his keynote at 19th Cloud Expo, Sheng Liang, co-founder and CEO of Rancher Labs, discussed the technological advances and new business opportunities created by the rapid adoption of containers. With the success of Amazon Web Services (AWS) and various open source technologies used to build private clouds, cloud computing has become an essential component of IT strategy. However, users continue to face challenges in implementing clouds, as older technologies evolve and newer ones like Docker c...
We all know that end users experience the internet primarily with mobile devices. From an app development perspective, we know that successfully responding to the needs of mobile customers depends on rapid DevOps – failing fast, in short, until the right solution evolves in your customers' relationship to your business. Whether you’re decomposing an SOA monolith, or developing a new application cloud natively, it’s not a question of using microservices - not doing so will be a path to eventual ...
The next XaaS is CICDaaS. Why? Because CICD saves developers a huge amount of time. CD is an especially great option for projects that require multiple and frequent contributions to be integrated. But… securing CICD best practices is an emerging, essential, yet little understood practice for DevOps teams and their Cloud Service Providers. The only way to get CICD to work in a highly secure environment takes collaboration, patience and persistence. Building CICD in the cloud requires rigorous ar...
DXWorldEXPO LLC announced today that ICC-USA, a computer systems integrator and server manufacturing company focused on developing products and product appliances, will exhibit at the 22nd International CloudEXPO | DXWorldEXPO. DXWordEXPO New York 2018, colocated with CloudEXPO New York 2018 will be held November 11-13, 2018, in New York City. ICC is a computer systems integrator and server manufacturing company focused on developing products and product appliances to meet a wide range of ...
Sanjeev Sharma Joins November 11-13, 2018 @DevOpsSummit at @CloudEXPO New York Faculty. Sanjeev Sharma is an internationally known DevOps and Cloud Transformation thought leader, technology executive, and author. Sanjeev's industry experience includes tenures as CTO, Technical Sales leader, and Cloud Architect leader. As an IBM Distinguished Engineer, Sanjeev is recognized at the highest levels of IBM's core of technical leaders.
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 ...
We are seeing a major migration of enterprises applications to the cloud. As cloud and business use of real time applications accelerate, legacy networks are no longer able to architecturally support cloud adoption and deliver the performance and security required by highly distributed enterprises. These outdated solutions have become more costly and complicated to implement, install, manage, and maintain.SD-WAN offers unlimited capabilities for accessing the benefits of the cloud and Internet. ...
As Cybric's Chief Technology Officer, Mike D. Kail is responsible for the strategic vision and technical direction of the platform. Prior to founding Cybric, Mike was Yahoo's CIO and SVP of Infrastructure, where he led the IT and Data Center functions for the company. He has more than 24 years of IT Operations experience with a focus on highly-scalable architectures.
Headquartered in Plainsboro, NJ, Synametrics Technologies has provided IT professionals and computer systems developers since 1997. Based on the success of their initial product offerings (WinSQL and DeltaCopy), the company continues to create and hone innovative products that help its customers get more from their computer applications, databases and infrastructure. To date, over one million users around the world have chosen Synametrics solutions to help power their accelerated business or per...
Founded in 2000, Chetu Inc. is a global provider of customized software development solutions and IT staff augmentation services for software technology providers. By providing clients with unparalleled niche technology expertise and industry experience, Chetu has become the premiere long-term, back-end software development partner for start-ups, SMBs, and Fortune 500 companies. Chetu is headquartered in Plantation, Florida, with thirteen offices throughout the U.S. and abroad.
Dion Hinchcliffe is an internationally recognized digital expert, bestselling book author, frequent keynote speaker, analyst, futurist, and transformation expert based in Washington, DC. He is currently Chief Strategy Officer at the industry-leading digital strategy and online community solutions firm, 7Summits.