As is often the beginning of most anything we do, this story starts with necessity! Unfortunately for me, the necessity was caused by my own screw-up: I had to restore my wife’s computer from a backup and instead of giving files their original modified timestamp, I accidentally chose to set the timestamp to the current time! Well, now she lets me know how difficult it is to arrange our digital pictures into their appropriate months when the files are misdated!

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Think it’s a weird kind of question? Not for people who have worked (or are working) on applications that are moving from one framework to another. I happened to work on one such project where a transition from Struts to Spring MVC was being done over a few releases. Not unexpectedly, this approach of supporting two frameworks at the same time gave the development team its own share of interesting challenges. And one such issue was how to use a new technology i.e. Spring themes in both frameworks, of course we could choose not to use it in enhancements to legacy Struts based application flows but then that would have meant doing the enhancements twice.

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AJAX development requires deeper knowledge in JavaScript and there is a slightly different set of features in different browsers. There are also technologies created out there called JavaScript libraries – such as Ext JS and Yahoo User Interface – and JavaScript toolkits – such as Google Web Toolkit (GWT) and DOJO – that can help you ease the burden. Basically, the libraries’ role is to speed up development for the client side and take care of the browser compatibility holdups. Further, the toolkits offer even more infrastructure providing support for the development and deployment phases.

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What could be simpler than property files? In an enterprise application, it turns out, many things! In this post I’ll take a look at a few subtle complexities to managing properties in an enterprise Java Spring application, and hopefully demonstrate how a little fore-thought in design can yield big savings in terms of time, confusion, bugs, and gray hair down the road.

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JAXB (Java Architecture for XML Binding) is a very powerful and comprehensive XML binding framework for Java which can significantly reduce XML programming and testing time by abstracting cumbersome details specific to XML schemas. This post goes through a simple sample for generating a Java class from an XML schema and using JAXB for marshalling and unmarshalling.

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You get in to work, grab a cup of coffee, and start your day with a nice, simple, easy-to-read method that stores a value object in the database. By lunch, it has ballooned to 8 lines of code, most of which handle exceptional cases, and make sure that maintenance developers can handle them in testing and production. In this post, I will describe four approaches that I have seen for minimizing this problem and describe some pros and cons for each. The four approaches are, in no particular order:

* Aspect-Oriented Programming (AOP): define an advice class that gets executed whenever any method throws an exception. Log the exception in the advice.

* The catch-all method (i.e. highest interface/tier logging): Log no exceptions at lower levels and allow all runtime exceptions to bubble up. At the highest tier (such as a web UI, main executable, Web Service, etc.), catch all exceptions and log them.

* Self-logging exceptions: Define a base exception class that logs itself in the constructor (takes a message and possibly a Class as parameters). All exceptions in the application must extend from this base class (3rd party or library exceptions must be caught and re-thrown), but no application code should ever log an exception.

* Developer logging: As above, each developer logs exceptions as they see fit.

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