Handling null in Java

Its a problem I encouter in most JEE projects I’ve worked on so far. Handling null-values. But why is this a problem? And what strategies can we follow to reduce the problem? That is what I’m trying to find out in this post.

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Cleaner code: Inversion of logic

Design patterns

Almost all programmers have heard about and used design patterns. And there are a lot of them. Famous design patterns include the Singleton, Observer, Template method. These are all patterns that focus on objects and the relationship between them.

There are more groups of patterns, for example take Dependency Injection (or Inversion of Control). This is an architectural pattern. They tell you things about the design of the whole program. And there are specific pattern groups, like concurrency patterns.

These patterns help you solve common problems in a well defined way, other programmers will recognise the patterns used and it will help produce more maintainable code.

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Java EE 6 released, including Servlet 3.0

Today marks the release of Java EE 6. The reference implementation (Glassfish V3) has been released and the specifications are going into their final state very soon.

About two years ago, while I was attending the JavaOne conference, I first heard about the Servlet 3.0 ideas. As a web developer I’ve worked a lot with these Servlets so I was curious about the ideas. But what I saw wasn’t what I hoped for. On the contrary, what I saw was a huge mistake in my opinion!
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Java Generics for Compare

I’ve been developing with Java 5+ for quite a while now. Not all developers are this lucky, some are still stuck with 1.4… some even with 1.3! But my clients all made the excellent step forward to Java 5 (some even to 6). The problem is, they moved the runtime/JDK but forget to move their developers!

In Java 5 the language brings some good improvements, the for-loop is easy to understand, and almost all the developers are using this by now. The problem starts with generics. There is a part most developers understand, the Collections API. Almost all programmers use lists now as: List<Integer> instead of a plain old List. This is a good start, but it must not end here! First, I must admit, generics in Java can sometimes be hard and confusing (when using <? extends X> and <? super X>). So I’m not going to talk about any of this ‘hard stuff’. Its the use of ‘easy’ generics that can our lifes so much easier.

For example the piece of code below:

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