And now for something completely different: how to mind-map in color with a little help from ruby?

I like to mind-map and the tool I use is FreeMind. You can add icons to your nodes, import pictures etc.etc. You can also add some color to your mind-map; select a node and change the color. For some -strange- reason I wanted to have all my nodes in different colors and after one minute of selecting nodes, changing colors I already abandoned that idea => too tedious. Ruby to the rescue: Freemind stores your mind-maps in XML format and this little ruby script turns your boring mind-map into something colorful:

require 'rexml/document'
include REXML

def traverse_element(element)
    element.elements.each('node') do |e|
        e.attributes['COLOR']= ("#%06x" % rand(0xffffff))
        traverse_element(e)
    end
end

doc = Document.new(File.new("original_boring_mindmap.mm"))
traverse_element(doc.root)
out = File.new("new_colorful_mindmap.mm","w")
out.write(doc)

Nerdy? You bet ya.....

Filed under General | 1 Comment »

Why a blog on Java and telecommunications? There is no other industry for which the Java Community Process hosts so many specifications and I wonder if people are aware of this. Additionally, in May I'll be doing a session on both JavaOne and Telemanagement World conferences. A nice trigger for a series of blog postings that starts with an overview of where Java plays a role in the telecommunications industry and with each subsequent post zoom in on the subject of the sessions: OSS/J Order Management and SOA.

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Filed under Java, Telecommunications | 6 Comments »

Let's continue the EJAPP Top 10 countdown with number 6.

Caching is a funny thing. Done right it can improve the performance of your Enterprise Java application tremendously and can even be essential to reach acceptable performance levels, but sometimes caching itself can be the cause for your performance problems. Improper caching covers both cases.

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Filed under Java, Performance | 8 Comments »

Last week we discussed the incorrect usage of Java EE in the EJAPP Top 10 countdown. After that very broad topic, it's time for a very specific one on number 7.

The unnecessary use of XML is a boon to the performance of your Java EE application. XML has a number of interesting properties that cause it to be used for a whole range of functions in the average Enterprise Java application:

• as a configuration file format, e.g. Java EE deployment descriptors and Spring configuration files,
• as a remoting protocol, e.g. SOAP or Burlap, and even
• as a data storage format, e.g. Apache Xindice and eXist.

Someone once said that "XML is the noun and Java is the verb" and that has caught on. Unfortunately XML processing is heavy on CPU cycles and on memory usage.

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Filed under Java, Performance, XML | No Comments »

Continuing the EJAPP Top 10 countdown, it's time to talk about number 8.

Apart from leading to badly architected applications, incorrect usage of Java EE can also cause your application to perform poorly. This problem is particularly prevalent in older applications that were developed before the POJO/lightweight revolution a few years back.

Lightweight frameworks like Spring allow the developer to pick and choose the infrastructure services (transactions, security, distributed objects) that are needed. Java EE (or J2EE as we used to call it) offers all of them all of the time. Application servers are tuned to not spend a lot of CPU cycles on the infrastructure services that are not used, but some developers succumb to the temptation to use these features when they are not needed. Not helping all this are the "best practices" that came into being with the first J2EE versions, e.g. Sun's J2EE patterns.

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Filed under Java, Performance | 4 Comments »

I think people are getting too religious about following Agile methodologies. Agile principles and best practices are valuable for applying important lessons that have been learned in software development. However, the drawback of following methodologies is that it takes experience and wisdom to know which of their practices work best in a particular situation. Best practices and even principles that are blindly followed may do more harm than good, even if they are Agile.

To illustrate this, consider the following two Agile principles (http://agilemanifesto.org/principles.html):
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Filed under Agile | 2 Comments »

In a previous blog I described the minimal basic configuration of the Acegi framework. In this blog I'll show you how easy it is to implement your own security provider. There can be many reasons why you would want to implement such a customized security provider. In my case I had to secure an application using user information that was being maintained by an external php-based application. The user information could only be retrieved using a web service. In this blog I will demonstrate several ways to implement your own security provider.

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Filed under Security | 2 Comments »

How to get started with the Acegi framework and implement your own Security provider?

In the old days folks used the J2EE securing capabilities of the app server. This is of course still an option, but there are superior alternatives like the Acegi framework. Acegi is far from new and with the latest releases it has become a very stable and easy-to-use framework, especially when combined with Spring. I had to implement a custom security provider for a customer and was very surprised how easy this was accomplished. This blog describes the steps I took to get started with Acegi.

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Filed under Security | 3 Comments »

Spring is a great framework, but I expect that some Spring based applications are subject to visibility problems (a type of concurrency problem). This blog entry describes the cause and effects of this problem, and also how it can be solved.

Visibility problems

Most programmers don't have much experience with multi threading and have a very simplistic view on reality: if a thread makes a change to a variable, this change is directly visible to all other threads that access the same variable. This view is called sequential consistency, but the problem is that no virtual machine automatically provides this view.

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Filed under Concurrency Control, Java, Spring | 6 Comments »