Saturday, December 23, 2006
I wonder has anyone thought about spagetti products. It may not consist of Spaghetti code, but uses myriad of technologies, frameworks, and solves variety of domain problems that its very difficult to add a new component in it. Hence, it becomes difficult to adding a new component in a consistent way, due to lack of consistent architecture and implementation.
Given a product which uses a range of technologies and has evolved over period of time, the team responsible for adding a new component has a wide variety of technological choices to make. And sometimes, team pick the technology which they are comfortable with.
And, we have something, what I would like to call, a Spaghetti product.
Add to this, the changes in team over period of time, transitioning of product from one team to another team, outsourcing to partners, the product also runs the risk of developing spaghetti code. Over a period of time, it not only becomes difficult to maintain the product, but it also becomes equally difficult to enhance the product features or to add new components.
Such products are typically a good candidate for re-architecture and re-design.
Re-architecture and re-design do not guarantee that new product wont evolve to become spaghetti product over a period of time. It just adds a new life to the product.
It seems that every code ultimately becomes spaghetti code at some point, and every product becomes spaghetti product.
I also wonder whether Frameworks too will become spaghetti framework one day. Take Spring for example. It started as IoC container and light weight alternative to EJBs, but it has now lot of extensions such as Web Flow, Acegi security, and others which make it more spaghettier. Even though I am yet to read the whole of Spring 2.0 documentation, I sometimes feel that there is just too much being offered in one place, and probably its the pressure to keep adding value to the framework which forces teams to extend it release after release. Extensions may make sense in some cases, and in some cases it may be just an overkill and something which is added to level with competing frameworks.
Sometimes, the technological advancements also forces extension. For instance, addition of annotations in Java 5.0 has pretty much lead to a wave of augmenting XML based configuration with annotation based configuration.
Monday, December 18, 2006
And in the J2EE world, the best way you could possibly test code is by using Junits.
Junit is simple testing framework designed around two key design patterns: the Command pattern and the Composite pattern. They are simple to write and check their own results and provide immediate feedback and they are relatively inexpensive to write (oh yeah - they are free in terms of cost).
A TestCase is a command object. Any class that contains test methods should subclass the TestCase class. A TestCase can define any number of public testXXX() methods. When you want to check the expected and actual test results, you invoke a variation of the assert() method.
TestCase subclasses that contain multiple testXXX() methods can use the setUp() and tearDown() methods to initialize and release any common objects under test, referred to as the test fixture. Each test runs in the context of its own fixture, calling setUp() before and tearDown() after each test method to ensure there can be no side effects among test runs.
TestCase instances can be composed into TestSuite hierarchies that automatically invoke all the testXXX() methods defined in each TestCase instance. A TestSuite is a composite of other tests, either TestCase instances or other TestSuite instances. The composite behavior exhibited by the TestSuite allows you to assemble test suites of test suites of tests, to an arbitrary depth, and run all the tests automatically and uniformly to yield a single pass or fail status.
Here is an FAQ on Junits:
and here is an excellent introduction to Junits
Monday, May 29, 2006
This seems to be a very promising application. Any one tried to experiment with it.
With Gapminder, as Ionut writes, “you can visualize World Development Indicators from The World Bank. You will see a scatterplot where each bubble represents a country. The position of the bubble is determined by the indicators on the axes. The size of the bubble represents the population of the country.” [Thanks Justin Flavin and Ionut Alex. Chitu.]
Tuesday, May 23, 2006
Google released a tool kit to create light weight web applications called Google Web Toolkit.
You can find it at http://code.google.com/webtoolkit/
As one person said, this was the presentation that made the show. it is both a technical tour de force and an amazingly useful tool at the same time. I will try and come back and cover this a little more later, and also get my JavaOne Day One roundup posted.
Thursday, January 26, 2006
I was just skimming through Macromedia Flex and I should admit, it"s very impressive.
It seems to be a pretty good way to create Rich Internet Applications (RIA). Since the flash player is already available in millions of computers, it is fast becoming a standard to deliver RIAs and it might even replace quicktime and other media applications. And Flex provides the perfect server side component for Macromedia to take advantage of all those computers with flash.
Macromedia Flex is a presentation server that developers are using to build a new generation of Rich Internet Applications (RIAs). Rich Internet Applications combine the usability of desktop applications with the administrative advantages of the web.
The Flex language capitalizes on the strengths of two popular development paradigms: markup languages and object-oriented programming languages.
Check out a HelloWorld.mxml (Classic Hello World example, this time in flex). You define the user interface declaratively using MXML and write the copy logic in ActionScript in the click event handler for the Button component.
<?xml version="1.0" encoding="utf-8"?>
<mx:TextInput id="source" width="100"/>
<mx:Button label="Copy" click="destination.text=source.text"/>
<mx:TextInput id="destination" width="100"/>
The first time a user requests HelloWorld.mxml, the server compiles the MXML code into Flash bytecode (a SWF file). The server then sends the generated SWF file to the client where it executes in Flash Player. Subsequent requests to the same MXML document bypass the compilation process
Now, where does this fit in with J2EE?
Flex is a presentation server installed on top of a J2EE application server or servlet container, a rich library of user interface components, an XML-based markup language used to declaratively lay out these components, and an object-oriented programming language which handles user interactions with the application. The result is a Rich Internet Application rendered using Flash Player and developed using industry standards and a development paradigm familiar to developers.
Developers use two core languages to create Flex applications. The first core language is MXML, the Macromedia Flex Markup Language, which includes a rich set of XML tags that allows developers to layout user interfaces. MXML can also be referred to as an XUL, or XML UI Language. These tags can be extended, unlike HTML, with additional capabilities that the application requires. Other MXML constructs allow you to call remote objects, store data returned in a model, and customize your own look and feel to MXML components.
The Flex server is responsible for translating the MXML and ActionScript components into Flash bytecode in the form of .SWF files. This process is similar to compiling JSP files into servlets by a Java web application container. The SWF file is executed on the client in the Flash runtime environment. The Flex server provides other services such as caching, concurrency, and handling remote object requests.
For a great example check out http://maps.yahoo.com/beta/index.php which is all Flex based. Wow!
Talkbacks and comments always welcome.
Tuesday, January 24, 2006
EPP is a protocol that is used for various DNS registries talk to each other.
So, for example when you want to register a domain or transfer a domain from one provider to another, EPP provides an easy way to do this and to manage the work flows associated with these transactions.
EPP stands for Extensible Provisioning Protocol.
The EPP core protocol specificationprovides a complete description of EPP command and response structures. A thorough understanding of the base protocol specification is necessary to understand the mapping described in this document.
Specifications for other objects may be developed as needs are identified.
Thursday, January 19, 2006
This kind of incompatiblity between application servers, database vendors and third party API developers is causing serious productivity problems and is causing costs to jump through the roof for major J2EE implementation and most seriously causing a serious fragmentation of the market. This allows alternate frameworks (like Spring, Hibernate etc.) and competing technologies (like .NET etc.) to hit J2EE where it hurts!!
Tuesday, January 17, 2006
But in any case, looks like we are already having the FIRST Ajax Seminar in NYC on March 13 and San Jose on April 24.
Here is a list of some of the speakers that are scheduled to speak at the seminar:
Jesse James GarrettFather of AJAX
Jesse James Garrett is the Director of User Experience Strategy and a founding partner of Adaptive Path, the world's premier user experience consulting company. He is author of The Elements of User Experience (New Riders), and is recognized as a pioneer in the field of information architecture. Jesse's clients include AT&T, Intel, Crayola, Hewlett-Packard, Motorola, and National Public Radio. Since starting in the Internet industry in 1995, Jesse has had a hands-on role in almost every aspect of Web development, from interface design and programming to content development and high-level strategy. Today, information architects around the world depend on the tools and concepts he has developed, including the widely acclaimed "Elements of User Experience" model. He is co-founder of the Information Architecture Institute, the only professional organization dedicated to information architecture. He is also a frequent speaker and writer whose work has appeared in numerous publications, including New Architect, Digital Web, and Boxes and Arrows.
Scott DietzenOne of the Fathers of WebLogic and J2EEPh.D.,
President and CTO, Zimbra Prior to Zimbra, Scott was CTO of BEA Systems where he was the principal architect of the technology strategy for the WebLogic, which drove the company from $61 million in revenue for the year prior to WebLogic's acquisition to over $1 billion. He was also one of BEA's top spokespersons. He is widely credited with helping put together the J2EE standard, launching the Web application server category, launching the Java Community Process, and driving the web services collaboration with Microsoft and IBM. Prior to WebLogic, Scott was Principal Technologist for Transarc (acquired by IBM), a developer of distributed transaction and information sharing systems. In addition to working on Internet infrastructure since 1991, Scott has managed teams focused on sales, marketing, product management, and standards. He earned his Ph.D. and M.S. in Computer Science and B.S. in Applied Mathematics and Computer Science from Carnegie Mellon University.
David Heinemeier HanssonCreator of Ruby on Rails
US-based since November, David Heinemeier Hansson is the development lead of Rails, also known as Ruby on Rails, which the official Ruby on Rails website irreverently describes as "a full-stack, open-source web framework in Ruby for writing real-world applications with joy and less code than most frameworks spend doing XML sit-ups." He has had help from a lot of contributors. David is the creator of applications like Instiki, Basecamp, and Ta-da, and has now joined the Chicago-based team of 37signals.com, a privately-held company founded in 1999 and committed to building the best web-based software products possible with the least number of features necessary. David will give his first presentation on “AJAX in Rails” at the “Real-World AJAX” one-day seminar.
There are plenty of other speakers as well and the list looks impressive.
The cost varies from about $1000 to about $1300 (a bit expensive considering it's only for 1 day)
Monday, January 16, 2006
AJAX is a web development technique for creating interactive web applications using a combination of:
• XHTML, HTML and CSS for marking up and styling information.
• The XMLHttpRequest object to exchange data asynchronously with the web server.
• And finally XML for transfering data, although any format will work, including preformatted HTML, plain text.
Ajax's prime advantage over other Rich Internet Application technologies is seamless integration with HTML so it can be used incrementally without the need to change existing Web content.
However, the AJAX technology is still immature, and tools and frameworks have not gained a lot of traction yet. It involves a lot of work with toolkits and libraries.
Rich Internet Applications are those applications that offer functionality beyond standard HTML frames and hyperlinks. A well-noted example of Ajax functionality is Google Maps.
The dominant RIA technology in use today is Macromedia Flash/Flex. Other RIA technologies include the user interface markup language for the Microsoft Windows Presentation Foundation called XAML (Extensible Application Markup Language), Mozilla's XML-based user interface language XUL, droplets and Java applets, and Microsoft's upcoming Windows Presentation Foundation/Everywhere (WPF/E).
Microsoft is planning to roll out an Ajax framework extension, code-named Atlas, which looks very promising.
The Tibco tool for writing Ajax applications looks quite good.
In addition to IDEs or framework extensions, there are also Ajax UI tools and remoting tools available -- more than four dozen in all, including both proprietary and open source offerings.
To date, much of the Ajax attention has been focused on business-to consumer Web sites, but Ajax does have some synergy with Web services and SOA, and it could impact enterprise portals.
Some people believe Ajax will be a major comeback factor in portal solutions. Portals came out with a lot of hype, but in reality they're not a quite a silver bullet. But the ability to combine Ajax presentation with portal functionally will enhance the corporate user experience.
The analogy I use is the browser popup window, which was originally a usability feature, but it was so abused it became a pariah of the Web and people disabled them.
So as of now, there is no clear data whether AJAX is just hype or a reality that will make its way into enterprises.
My personal suggestion is to wait and watch to see how the industry embraces AJAX but in the meantime, do prepare yourself with at least the basics of AJAX so when enterprises are ready to embrace AJAX, you already are!!
Here are some nice links for you to get started:
Talkbacks and comments are always welcome.
What is Geronimo?
Another open source application server? Haven’t we already had enough of open source application sources - JBoss, JonAs, going back all the way to Tomcat? (Agreed Tomcat has always been more of a web container than a J2EE container).
But seriously, Geronimo, is the new application server built by Apache (widely considered as the best and most superior open source groups out there) and they built the Apache web server that is still running the majority of internet. So coming from Apache, a J2EE container is a big deal.
According to the official Geronimo website:
Geronimo is currently compatible with the Java 2 Enterprise Edition (J2EE) 1.4 specification. When compared to other application servers such as JBoss, WebLogic and Websphere, Geronimo's most distinctive features are its:
- BSD-style license, which allows it to be modified for and embedded within commercial, closed source software (unlike the popular GPL and LGPL licenses)
- Modular GBean-based architecture, which allows users to remove unneeded services and build very lightweight configurations of the server
- Non-Profit ASF leadership, which provides legal protection, ensures stability across the loss of individual contributors and insulates the project from commercial conflicts of interest
- Diverse support community, in which companies compete freely and openly to provide services, with none enjoying any particular trademark advantage
What makes Geronimo so special as compared to other Application Servers (other than the Apache name?)
- Here is what I think the main points about Geronimo are:
- Complete J2EE 1.4 Application Server
- Built on best of breed components (Tomcat/Jetty, OpenEJB, HOWL, etc.)
- Modular architecture (server core plus services grouped into “configurations”)
- Open community & open license
- Fast JMS server included
- An excellent Web-based management console included
Having said that, I must say, in my trials I noticed that Geronimo is not yet industry, productions standards but that may be just a temporary phenomenon. The application server has a lot of promise and even though BEA, IBM and other commercial vendors are a bit worried, Geronimo could turn out to be the greatest threat to another application server – JBoss.
After all, who would buy a “commercial” open source application server like JBoss when a completely free and superior version like Apache Geronimo is available?
Saturday, January 14, 2006
What does a good J2EE developer have to know in addition to understanding
the difference between abstract classes and interfaces?
Usually employers are looking for people with at least 10 of the following skills:
- Java Servlets
- Struts or a similar framework
- JMS Any commercial message-oriented middleware
- One of the major application servers(Websphere/Weblogic/JBoss)
- Couple of relational database management (Oracle/MySQL/DB2) systems
- Any UML modeling tool, several design patterns (at least a Singleton!)
- Familiarity with Unix. Next year JavaServer Faces and Hibernate will most likely be included in this laundry list.
Good knowledge of the business terminology of your potential employer is also important. I’m not sure about the Silicon Valley or Europe, but here in New York just being a techie may not be good enough to get a senior job.
For example, if you’re applying for a Java position in a financial brokerage company and don’t know what a short sale is, this may be a showstopper. If you are a senior developer, you should
be able to hit the ground running.
Try to find out from your recruiter as many details as possible about the business of your potential employer, do your homework, and you’ll get the job!