not idle

When I wanted to pack a simple java desktop application as a Web Start application I had problems with already signed jars – after Web Start dialog showed on the screen, I got “jar resources in jnlp file are not signed by the same certificate” problem. There exist other ways to tackle the problem (for [...]

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I recently updated Openfire server (we use on SLA@SOI project for components to communicate through PubSub) to version 3.7.0, but the server began crashing (java.lang.OutOfMemoryError: Java heap space) and I had to restart it quite often (couple of times a day). After googlin’ and forum reading I tried with disabling PEP (Admin console > Server [...]

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Recent Java networking problems, anyone?

Thursday, December 24th, 2009

I just noticed that all of a sudden no Java program can access network anymore. After reinstalling a fresh Sun JDK, checking all policies and properties and proxies, none of which helped, I finally managed to ask the all-knowing One the right question. It’s got to do with premature eja… erm … IPv6 exclusivity. Checking [...]

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Netbeans Classloaders

Tuesday, September 29th, 2009

Netbeans classloader system consists of three types of classloaders, namely module classloader, system classloader and original classloader. Usually, module classloaders are used to load classes and resources from within the module itself. However, there are situations when you need to access classes and/or resources from other modules. Imagine two modules, A and B. Class Ca [...]

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Boolean state menu items in Netbeans

Monday, September 28th, 2009

Netbeans platform supports different kinds of actions (always enabled, CallableSystemAction, CallbackSystemAction etc). However, it was not clear to me how to create an action that could be used for toggling the state of the system. Initially, I experimented with Presenter.Menu interface and provided my own implementation of the JCheckMenuItem but couldn’t get the platform to [...]

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Java: dynamically adding jars at runtime

Wednesday, January 28th, 2009

If you’re using factory pattern and want to separate factory from the implementations (so you only load the implementation you need) I recommend using Jar Class Loader. Here’s what the author has to say: JCL is a simple Java API that allows loading classes from Jar files. It uses a custom class loader to load [...]

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JavaBlend conference

Wednesday, October 15th, 2008

The first Java conference in Slovenia took place at the Castle of Ljubljana. Eight interesting presentations by international speakers introduced different aspects of popular Java technologies and libraries. Among others Seam 2 (platform for building rich internet applications), Lucene (text search engine library), Hibernate (object-relational mapping library) and J2ME (environment for applications running on mobile [...]

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GWT 1.5 RC 1 Released

Thursday, May 29th, 2008

The first release candidate of the new GWT 1.5 is finally available. It supports Java 1.5 syntax (generics, improved for-loop, annotations, …). The new JRE emulator introduces new classes from Java runtime: java.sql.Date, java.sql.Time, java.sql.Timestamp: no more hacks when using Hibernate StringBuilder various other containers: TreeMap, TreeSet, PriorityQueue, … For a complete list of new [...]

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