Pinderkent

Today I read an article written by Davy Brion a few months back. It talks about his experiences interviewing several developers, and some of the techniques and concepts that some of the candidates were and weren't familiar with. Namely, he found Java developers to be more familiar with dependency injection, inversion of control, test-driven development, aspect-oriented programming, object-relational mapping, and so forth. While he seems to see such knowledge as a benefit, I'm not so certain it truly is.

The Java community is well-known for their adoption of design patterns and frameworks. One of the most popular frameworks is the Spring Framework, which offers an IoC container, an AOP framework, a data access framework, and so on. AspectJ is widely used for AOP. Many projects use the Hibernate ORM library. And JUnit was integral in bringing test-driven development to the mainstream.

However, various notable software developers have suggested that design patterns are merely missing language features. In many cases, this does appear to be the case. Some common features and techniques of functional programming languages, for instance, render many design patterns irrelevant.

Unfortunately, design patterns and various frameworks have become quite embedded within some portions of the wider software development community. The devotion that some developers have to the "cause" can best be described as a religious in nature. It is particularly strong within the Java community, and to a lesser extent (usually Java expats) within the .NET community.

For every case when I've seen a techniques like IoC or DI used sensibly, there are many, many more cases of systems I've dealt with where they've became huge obstacles and only served to unnecessarily complicate the software system. The use of ORM systems is another frequent problem area. The first major problem that arises is usually performance-related, with the object mapper sometimes generating some truly horrific database queries, or bringing back huge quantities of data that are never used. In short, what was meant to save time ends up wasting it.

We often see these problems arise with business software. Often times, this sort of software is relatively simplistic in implementation, with most of the complexity coming in the various and often inconsistent business rules that need to be supported. So what I think we've seen in many cases is software "architects" who feel the need, for whatever reason, to build horribly complex systems where they're not needed. Design patterns, along with the copious use of frameworks and over-generalizations, facilitate this sort of development.

Soon, what should be simple systems quickly explode in complexity. The quality of the software drops, even though there may be a huge number of automated unit tests. Usability becomes a nightmare. Simple maintenance tasks and bug fixes take far longer than they should, because the developers need to unravel unnecessary abstractions.

Some of the most successful business software systems I've dealt with have evolved over time, often with different parts being written in isolation from one another. The only "frameworks" used were developed in-house, tailored specifically to the problems at hand. Any "design patterns" used were those that were observed naturally occurring in the software system as it grew. Instead of trying to provide overly-abstract and highly-generalized "solutions", each part of these software systems performed a very specific role, and did that role well.

So if we feel the need to start explicitly using design patterns or frameworks for our software, maybe we should take those feelings as a warning alarm. Finding a more powerful and expressive programming language may be a good place to start. After that, the reasons for employing design patterns or frameworks should be considered very carefully. It often ends up being quicker and easier just to sit down and write the software, rather than planning and debating and designing it. This is especially true if such techniques are used merely to add complexity to what should be a simple system, just to make it more challenging for the developers.

James Hamilton recently wrote about the use of low-cost and low-power servers, with a focus on ARM-based systems running Linux. He points out that the linux-arm.org site itself is running on such a setup. Looking at the specs of their systems reminds me of the servers we used in the mid-to-late 1990s, and even into the 2000s. Having been involved with software development for many years now, with much of my work revolving around networked business applications and server applications, I find this to be an interesting topic.

Clearly, a huge part of the problem today is the software we'd be running on such hardware. With the rise of Java, and especially frameworks like Ruby on Rails, far less of our hardware resources are used for actually performing the work of our software applications, and instead go towards powering the numerous frameworks, virtual machines, and platforms typically underlying our applications. Indeed, it has gotten so bad that some people are surprised when their Ruby on Rails-based Web application can handle "multiple requests per second", on modern hardware, without exhibiting performance problems.

Most recently, I wrote about Stack Overflow's outrageous hardware usage. Give the generally simplistic nature of that site, and the huge amount of processing power offered by today's low-end hardware, it's almost absurd to see how much they're apparently using.

When discussing lightweight servers, we shouldn't forget to consider the use of NetBSD instead of Linux. Aside from it already offering several ports to various ARM-based platforms, NetBSD is among the highest-quality open source software out there. I know of one person who used NetBSD on old PCs to serve images. I've also advocated it as an alternative to lightweight Ubuntu Linux distributions, as well as for use on low-power systems like Intel's classmate PC.

People today seem to forget just how powerful a typical server is today. Even the ARM-based servers that James mentions, or those powering the linux-arm.org Website, sound much more powerful than what we used a decade ago. That's not unexpected, of course. The cost of hardware rapidly drops, while its capabilities rapidly increase. Unfortunately, our software systems seem to eat up those gains rather quickly.

The main barrier to the widespread use of low-power and low-cost servers will likely be our existing software, frameworks, and platforms that use hardware resources very inefficiently. Instead of trying to salvage those, many of which are already a lost cause, perhaps we should be more willing to start from scratch, strip out all of the unnecessary layers of software that have accumulated, and make better use of functional programming languages like Erlang and Haskell. So not only would we get the benefits of using more efficient hardware, but we'd also get a much simpler and efficient software platform upon which to build our applications.

Joe Stump recently wrote about why he switched from PHP to Python. What he says is absolutely true. He nails down many of the problems with PHP, and also lists many of the benefits of Python. In the end, however, I think we can just sum up the comparison between the two languages as being one of comparing Python's professionalism versus PHP's amateurism.

When I describe Python as being professional in nature, I am referring to the emphasis on care, contemplation, quality, and doing-the-right-thing-even-if-it's-difficult we generally see embraced by the Python community. Like Joe mentions in his article, the language itself exhibits a high degree of sensibility, consistency and predictability. It has clearly been carefully evolved and grown, rather than having features and functionality tossed on here and there. It's a language developed by people who know what they're doing, and it's a language used by people who know what they're doing.

On the other hand, we've seen much of the opposite out of the PHP community. The language itself is a good testament to the general preference of that community towards doing things quick-and-dirty, rather than correctly and with care. It's full of quirks, it's inconsistent, and generally a jumble of differing ideas and philosophies. We've seen this happen with its standard library, as well. With the core platform having such poor quality, any software build upon it typically ends up suffering from quality and security problems, too.

It's no wonder that so many developers are moving away from PHP towards better languages and environments like Python and Ruby whenever possible. PHP is deceptively attractive. Sure, it's widely supported, and yes, it's got a large standard library. But it has many hidden and not-so-hidden costs, including horrid maintainability of applications written in it, numerous security flaws within critical code, and numerous hurdles towards developing decent software. Even if the perceived costs seem higher when using a more professional language like Python, in the long run it becomes the only viable choice when the alternative is something as amateurish as PHP.

While some descriptions of pair programming suggest that "all code to be included in a production release" is to be developed jointly by two programmers working in tandem at a single computer, that isn't a steadfast rule.

Teams wishing to employ such a development technique can be flexible about their pair programming arrangements. One team I worked with in the past only chose to use pair programming while developing the most critical parts of their software system. This allowed for the core functionality to be well-understood by all of the developers, but as soon as that work started to stabilize, they each went back to working on code alone. But as soon as core functionality had to change, pair (or even triplet, in some cases) programming was used.

This proved quite effective. Code that the team agreed was trivial could quickly be developed by a lone developer without too much overhead, while more complex or critical changes still had the oversight and involvement of at least several team members. They managed to strike a very good balance, which allowed them to develop their software quickly and efficiently, while also helping to keep the number of bugs to a reasonable level.

Other teams using pair programming shouldn't be afraid to experiment with introducing some flexibility into their process. It is possible to practice pair programming even if it's only done some of the time, or even just when absolutely necessary. Given that each development team's situation and software system is different, some teams may be best of pair programming only 20% of the time, while others are best off pair programming at or near 100% of the time. It should be tailed to each team's specific needs.

I recently saw an article about the accepted Project Coin changes that are planned to be included in JDK 7. This is some good news for the Java community. After a relatively long period of stagnation concerning the evolution of the Java language, and some fierce competition from C#, these are the sort of practical changes we need to see.

Most of these proposed changes aren't exactly revolutionary. Several of them have already been implemented for some time in C# and other .NET-based languages. They've proven to be effective there, and will hopefully bring the same benefits to Java.

The Automatic Resource Management proposal is a good example of a feature that is badly needed in Java. The using statement of C#, and the Using statement of VB.NET, have proven this concept. They make it safe and easy to ensure that certain non-memory resources are disposed of appropriately. This is exactly the sort of practical language-level change that Java needs.

The Strings in Switch proposal is another one that suggests a very useful change. Not being able to use a switch statement to select a case based on a string value has always been an annoyance to me.

The Improved Type Inference for Generic Instance Creation proposal may help making coding quicker, although I'm not convinced it's as beneficial as it sounds. Although it reduces what some may consider to be redundancy in code, most decent Java IDEs offer auto-completion support that helps prevent a programmer from actually typing out the parameterized types. And we do lose some detail within the object instantiation code, which otherwise is self-documenting in some sense. I think the benefits of this change will require some experimentation once an implementation is available.

Some of the other proposed changes, such as the addition of language support for JSR 292 and the collection-related changes don't seem as sensible to me. In the case of adding more support to the JVM and the Java language for supporting dynamically typed languages, I think this is a bad idea. The JVM itself is better suited to statically typed languages, and trying to hack on support for dynamically typed languages may just result in further bloat.

In the case of the collection-related changes, we are getting to the point where a major reworking of the collection classes is in order. We already have older classes like java.util.Hashtable and java.util.Vector, as well as the Java Collections Framework, and then all the changes that were made to both groups during the introduction of generics with Java 5. Trying to further build on the existing mess may just make the situation worse. But a clean up would be massive, and would have many repercussions on existing software. So there may be no easy answer here.

The acceptance of these proposals is a very good sign. They show the sort of activity and change needed to keep the Java programming language and platform relevant in the face of numerous other competing programming languages and platforms. I do hope that we get to see these implemented in JDK 7, as some of them do sound to be practical and badly needed by Java developers.