Java IoT Authors: APM Blog, Stackify Blog, Liz McMillan, Elizabeth White, Yeshim Deniz

Related Topics: Java IoT, Open Source Cloud, Eclipse

Java IoT: Article

JDJ Cover Story — Agile Java Development with Spring, Hibernate, & Eclipse

A roadmap for building enterprise-class applications using agile methods a POJOs

After getting a head of gray hairs and a quickly receding hairline, I have learned that the simplest solutions are often the best. Having worked with Java since 1995 and various software development lifecycle methodologies over the years, I have seen things grow complex in these areas. Thanks to some new lighter-weight Java tools and agile methods, I can provide a fresh perspective on developing Java applications in an agile manner.

This article is different from typical Java articles for two reasons. First, instead of providing in-depth details on some API or cool tool, it provides a roadmap for building enterprise-class Java applications using agile methods and plain old Java objects (POJOs). Second, it covers a lot of ground, from conceptualization through deployment, so for the sake of brevity, there are minimal code excerpts; however, there's a completely functional sample timesheet application called Time Expression (with source code) built using Spring, Hibernate, Junit, and Ant available at visualpatterns.com/resources.jsp.

We have a lot to cover so let's get started.

Agile Manifesto
In 2001, 17 software experts (including Martin Fowler, Kent Beck, and Jon Kern) got together to discuss lightweight approaches to software development; they jointly defined the term agile. The outcome of this was the "Manifesto for Agile Software Development," a set of values and principles for these agile methods.

The term agile incorporates a wide range of methods; some of them include Extreme Programming (XP), Scrum, Feature Driven Development, Agile Modeling, and Crystal. Many methodologies tend to include both process and modeling since they often go hand-in-hand; we will look at both next. For details on the Agile Manifesto and various agile methods, visit the agilemanifesto.org and agilealliance.org Web sites.

Agile Processes
One of easiest agile processes to understand is Scrum. While XP tends to steal the limelight in the agile community, it's a bit more involved than Scrum. However, the two are highly complementary since XP provides a set of excellent engineering practices whereas Scrum is more about product/project management. In fact, these days I tend to recommend becoming "agile" by bringing in Scrum first, then adding XP practices one at a time, as and when needed since moving entirely to XP-based development (from waterfall) is a rude awakening for many organizations and requires a fundamental mind shift that many projects aren't ready for.

So, how does Scrum work? Simple. We gather a list of new features or change requests for an application in a product backlog. For our sample application, Time Expression, these could include:

  • Hourly employees will be able to sign in to a Web application and enter their hours for each day of a given week.
  • The employee's manager must approve the timesheet.
  • After a timesheet is approved or disapproved, notification is sent to the employee indicating the updated status of the timesheet.
  • And so on...
From here, we simply take the highest-priority features, move them to a sprint backlog, and implement them in one-month (or shorter) iterations called sprints, and continue having monthly sprints till all the features are implemented. Each sprint (or iteration) contains the entire software lifecycle, in other words, detailed requirements/analysis, design, coding, unit/acceptance testing, and deployment of production-ready code. Scrum also suggests having a planning meeting at the beginning of a sprint and a review at the end of the sprint to discuss lessons learned or the next set of features to implement in the following sprint. Other than that, we have a short daily meeting (say, 15 minutes) to discuss the project's status. Figure 1 depicts the Scrum process. Visit controlchaos.com for details on Scrum.

A common theme of agile processes is iterative development. For example, XP works like Scrum, however, it uses the concept of quarterly releases with weekly iterations as shown in Figure 2. Also the features are provided in the form of user stories, typically written by the customer using one to three lines to describe the feature. My explanation of XP is overly simplified; there's a lot more to it such as pair programming, sit together, and continuous build. Visit extremeprogramming.org for details on XP.

So now we've looked at two agile processes, Scrum and XP. These help in gathering user feature requests and overall project management. However, as developers, we need to implement features by engineering them into software applications, so let's look at agile modeling techniques next, which can help us bridge the gap between user requirements and coding.

Agile Design
According to thefreedictionary.com, a model is "a preliminary work or construction that serves as a plan from which a final product is to be made...used in testing or perfecting a final product." So here I'll use the word "model" to describe diagrams and other artifacts.

Agile Model-Driven Development
Agile Model-Driven Development (AMDD) created by Scott Ambler provides guidelines for effective modeling. Instead of creating extensive models, AMDD recommends creating "good enough" models. One of my favorite Scott quotes is "your goal is to build a shared understanding, it isn't to write detailed documentation."

AMDD suggests two categories of models, requirements and architecture. Requirements models could include a domain model (Figure 3), usage models such as user stories or use cases (Figure 4), and UI models such as prototypes and flow map (Figure 5 and Figure 6).

Architecture models could include a freeform model like the one shown in Figure 7.

There really isn't a whole lot more to AMDD since it provides minimal guidelines for agile modeling. Visit agilemodeling.com for more details.

Agile Draw
Before moving to the next topic, let me briefly mention a new and elegantly simple technique called Agile Draw, which was used to draw Figures 3-7. This technique provides an alternative to the heavy-handed Unified Modeling Language (UML) but can also be used to complement UML. Agile Draw provides minimum guidelines for modeling and additional guidelines for adding appeal to these models using graphic design concepts. The core concepts behind Agile Draw include four basic components that make it a virtually notation-free modeling technique; these concepts include circles, boxes, lines, and text. Using them you can draw practically any model by hand or with a drawing program.

Visit agiledraw.org for more details.

One of the core aspects of agile methods is not to do too much design upfront so you can start showing results to the customer quickly by developing actual software versus producing comprehensive documentation that no one actually reads or maintains. Of course, the downside is that it cuts down on the amount of design done for an application. However, this isn't necessarily a bad thing since most programmers find better ways of doing things once they begin coding.

For example, we find cleaner ways of structuring our code after the first pass at it, perhaps by improving our own design or because we learned a better way of using a framework (such as Hibernate or Spring). This code improvement is known as refactoring and is considered a continuous design activity.

Refactoring is more than fluff; it's now appearing as a menu option in integrated development environments such as Eclipse and IntelliJ IDEA. Visit Martin Fowler's Web site, refactoring.com, for more information on refactoring along with a catalog of many refactoring techniques.

Other Design Considerations
While refactoring can help improve code, there might be other things you should consider upfront or in the first couple of iterations. Some of these include schemes for transaction management, exception handling, clustering, and application security (authentication, authorization, and encryption). Any enterprise-class project that doesn't at least consider these "big picture factors" upfront is asking for trouble later. One common problem found in XP projects is that a lot left for refactoring later never happens. Drawing bare-minimum architecture models like the one shown in Figure 7 upfront can help with general discussions about the important design considerations I've mentioned here.

More Stories By Anil Hemrajani

Anil Hemrajani is the author of the book titled Agile Java Development with Spring, Hibernate and Eclipse. He is the founder of Isavix Corporation (now InScope Solutions, Inc.), a successful IT services company, and DeveloperHub.com (formerly isavix.net), an award-winning online developer community that grew to over 100,000 registered members. He has twenty years of experience in the Information Technology community working with several Fortune 100 companies and also smaller organizations. He has published numerous articles in well known trade journals, presented around the world, and received and/or nominated for several awards. Anil can be reached via his web site, VisualPatterns.com.

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
JDJAgile 07/27/06 07:33:07 AM EDT

Hey Jeff, JDJ used all of the lastest Agile methods to develop their pages, so you see it's fast, it's now, it works! Far be it from me to stand in the way of progress. Give me a break, none of this crap has infiltrated coporate computing in the least. Just go back and code like the rest of us and stop patting each other on the back for your supposed genius.

I'm sure the author is well-meaning but when we're bombarded daily with titles like "The Four Quantum States of Ajax" I just gotta laugh. Do you really think all this stuff is changing anything?!

The engineering world wants real engineering not something built on top of existing frameworks decades old that works and works well.

Jeff 07/25/06 10:48:49 PM EDT

Holy crud, the pop up ad blocks the entire story even at 1360 x 768. Do you really need an Ad that big that requires a click to close? There are already adds on both margins and the in the header and Footer, the content is a thin ribbon down the center that get blocked by yet another ad. Just seems silly to me.

@ThingsExpo Stories
"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.
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...
"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.
"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...
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...
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.
"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...
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.
"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.
It is of utmost importance for the future success of WebRTC to ensure that interoperability is operational between web browsers and any WebRTC-compliant client. To be guaranteed as operational and effective, interoperability must be tested extensively by establishing WebRTC data and media connections between different web browsers running on different devices and operating systems. In his session at WebRTC Summit at @ThingsExpo, Dr. Alex Gouaillard, CEO and Founder of CoSMo Software, presented ...
WebRTC is great technology to build your own communication tools. It will be even more exciting experience it with advanced devices, such as a 360 Camera, 360 microphone, and a depth sensor camera. In his session at @ThingsExpo, Masashi Ganeko, a manager at INFOCOM Corporation, introduced two experimental projects from his team and what they learned from them. "Shotoku Tamago" uses the robot audition software HARK to track speakers in 360 video of a remote party. "Virtual Teleport" uses a multip...
A strange thing is happening along the way to the Internet of Things, namely far too many devices to work with and manage. It has become clear that we'll need much higher efficiency user experiences that can allow us to more easily and scalably work with the thousands of devices that will soon be in each of our lives. Enter the conversational interface revolution, combining bots we can literally talk with, gesture to, and even direct with our thoughts, with embedded artificial intelligence, whic...
SYS-CON Events announced today that Evatronix will exhibit at SYS-CON's 21st International Cloud Expo®, which will take place on Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA. Evatronix SA offers comprehensive solutions in the design and implementation of electronic systems, in CAD / CAM deployment, and also is a designer and manufacturer of advanced 3D scanners for professional applications.
Leading companies, from the Global Fortune 500 to the smallest companies, are adopting hybrid cloud as the path to business advantage. Hybrid cloud depends on cloud services and on-premises infrastructure working in unison. Successful implementations require new levels of data mobility, enabled by an automated and seamless flow across on-premises and cloud resources. In his general session at 21st Cloud Expo, Greg Tevis, an IBM Storage Software Technical Strategist and Customer Solution Architec...
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 ...
An increasing number of companies are creating products that combine data with analytical capabilities. Running interactive queries on Big Data requires complex architectures to store and query data effectively, typically involving data streams, an choosing efficient file format/database and multiple independent systems that are tied together through custom-engineered pipelines. In his session at @BigDataExpo at @ThingsExpo, Tomer Levi, a senior software engineer at Intel’s Advanced Analytics gr...