Welcome!

Java IoT Authors: Zakia Bouachraoui, Pat Romanski, Yeshim Deniz, Elizabeth White, Liz McMillan

Related Topics: Java IoT

Java IoT: Article

KISS + Swing = RAD

How to rapidly develop enterprise class Swing applications by keeping things simple

Java is a great language for developing enterprise applications. It's powerful, scalable, robust, secure, and typically very complex. As a software developer, I want to solve business problems, not spend man-months building the plumbing for my applications. This article will demonstrate how you can speed up the development and simplify the maintenance of enterprise-class Swing applications by keeping things simple. We'll look at ways to reduce the complexity of your application and the amount of custom code written for it. By limiting the complexity and the amount of plumbing code required, you'll develop more quickly, the application will be easier to maintain, and you can focus on the business logic that provides value to the customer.

In particular, I'll show you how to address three of the primary issues facing developers today:

  1. Persistence and object relational impedance mismatch
  2. Why too many technologies make development and maintenance difficult
  3. What to do when there's more application "plumbing" code than custom business logic
What Is Object Relational Impedance Mismatch and Why It's a Problem
Relational databases are the dominant database technology in the market today and they are well matched for use with procedural programming languages. However, with the move to object-based development languages (C++, Java, Delphi, etc.) it quickly became apparent that objects don't always map easily to relational tables and vice versa. This problem has become known as the object relational or impedance mismatch.

According to the Progress Software Web site, "An R.B. Webber study concluded that coding and configuring object relational (O-R) data access typically accounts for 30% to 40% of total project effort."

There are development and performance repercussions due to this mismatch. Developers must spend time writing code that breaks objects into pieces that can be saved to and re-assembled from relational tables and determining the best way to map objects to relational tables becomes more difficult as the objects grow in complexity. There is also a certain amount of overhead due to this assembly and breakdown of objects that impacts performance. Finally, queries can take longer since the application has to perform multi-table joins when retrieving complex objects from the database rather than just opening the object.

Historically programmers have dealt with this by writing a data access layer that manages the reading/object assembly from the database and object disassembly/writing to the database. Recently there's been an explosion in the number of XML-based mapping tools that attempt to replace the native language data access code with frameworks that define the mapping using XML. The problem with this approach is that while it provides a mechanism for persisting and retrieving objects, letting the developer to deal with objects exclusively, it requires quite a bit of additional work (defining and maintaining the XML mappings), incurs a performance hit when the objects are read from and saved to the database, and often requires the user to query the database with non-standard object query languages that aren't as mature and powerful as SQL.

Eliminating the Object-Relational Impedance Mismatch
One way to eliminate the object-relational impedance mismatch altogether is to use an object database for your application's persistence layer. Object databases are now mature, robust, and fast. More importantly, they provide an easy mechanism for persisting and retrieving objects without the overhead of a mapping framework. This means faster development, better performance, and less code to maintain.

You can browse a list of object-oriented databases at Service-Architecture.com. As with any technology, every vendor's implementation provides slightly different features and functionalities. It's important to review each one to find the one that best fits your project's needs. Next, I'll demonstrate how using an object database instead of a relational one can dramatically simplify and speed up the development of your entire application.

Example # 1: Defining and Accessing Objects Using An Object-Oriented Database
For these examples, I'll use InterSystems Corporation's Caché Database. The databases from db4objects, Matisse, and Progress also provide Java interfaces and transparent object persistence. However, features and implementations are specific to each vendor's database.

With InterSystems Caché you create your database by defining the objects that it will contain. The objects contain properties that are analogous to standard SQL data types and are mapped to Java datatype equivalents. The objects support aggregation and inheritance and can be projected as Java classes that include methods for retrieving, modifying, and persisting the object.

Note that Caché also lets you access your data/objects via an SQL projection, meaning you can access your data in either a relational or object-oriented fashion, whichever is most appropriate for the task at hand.

  • Aggregation: When an object is composed of other objects. For example, a car object is comprised of an engine object, a transmission object, four wheel objects, etc.
  • Inheritance: An object inherits the attributes and methods of another class (the base or parent class).
Savings # 1: Eliminate the Code and Performance Overhead of Mapping
By using an object-oriented database, you eliminate the need to create and maintain a mapping layer or data access layer. Not only does this speed up development, but you have less code to maintain and one less technology to learn. Look at Figure 1 to see what this means for the typical struts-based Web application.

The object database replaces four pieces of the application software stack. In addition, you will improve performance by eliminating the overhead of any XML mapping layer.

Just so you have an idea of some of the effort being eliminated, here's an example of a JDO XML map for a very simple object with only two fields. When using a mapping framework, you would normally create one of these for each object class in your database. By using an object database, you eliminate this step.

<?xml version="1.0"?>
<!DOCTYPE mapping PUBLIC "-//EXOLAB/Castor Object Mapping DTD Version 1.0//EN"
"http://castor.org/mapping.dtd">
<mapping>
   <class name="myapp.ProductGroup" identity="id">
     <description>Product group</description>
       <map-to table="prod_group" xml="group" />
       <field name="id" type="integer" >
     <sql name="id" type="integer"/>
   </field>
     <field name="name" type="string">
       <sql name="name" type="char" />
     </field>
   </class>
</mapping>

Example: Object Definition That Demonstrates Aggregation and Inheritance
Now I'll demonstrate how easy it is to create persistent Java objects using Caché by creating a very simple employee database.

Caché comes with a GUI tool called Studio that's used to simplify the definition of classes. You define classes in much the same way you would define relational tables - except when you're done, you can access the objects directly without writing data access code or using an object-relational mapping layer. Much of the class definition text can be generated by wizards in the application - but it can also be manually coded if desired. We'll define four classes including:

  1. An address class that can be reused as a property template in persistent classes
  2. A person class that represents a simple person object
  3. An employee class that extends the person class by adding additional properties
  4. Persistent Class: Persistent objects can be stored in the database.
  5. Serial Class: Serial objects can be embedded in persistent objects to create complex, reusable data definitions - such as addresses.
The Address Class
Here's the definition for the address class. Note that it extends a %Serial-Object so it can't be persisted by itself and must be included in a persistent class. Serial classes are great for simplifying the definitions of complex objects. We'll use this one to simplify the design of the Person and Employee classes.

More Stories By Richard Conway

Richard Conway is a software developer and technology consultant with more than 15 years of technology, project management, and information services experience. He has extensive experience developing Java/Struts-based web applications. He started focusing more on Swing based developments at the beginning of 2005 and has just finished a Swing-based client/server asset management project. He lives in Miami with his wife Patricia, is currently working on an EMR application, and plays sand volleyball in his spare time.

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
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...
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...
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...