Piotr Nowicki's Blog

JPA specification defines few types of EntityManagers / Persistence Contexts.

This post describes some of the pitfalls when coping with intercommunication between different modules (EAR, WAR, EJB-JAR) deployed in the same Java EE 6 Application Server.

In this post you can find often used Java EE 6 configuration files (along with their schema declarations to aid your IDE’s code assistant): CDI Name: beans.xml Version: 1.0 Content: <?

Few days ago I’ve created a simple interceptors spike-solution at Github.

Java EE 6 brings a lot new features.

In Midnight Commander when you press ctrl + \ you can access directory hotlist and you can quickly choose connection you want to establish.

Maven has some really great features.

More than 18 months ago I’ve posted my mock exam for Oracle Certified Expert Web Component Developer certification.

JPA’s FETCH JOIN is useful in cases when you want to eagerly load some lazy loaded collection of your entity.

You can easily create a fully functional, basic Maven repository on your web hosting provider’s account.

By default few of the security features are turned off in OpenShift JBoss 7.1 cartridge.

Yesterday I took the SpringSource Certified Spring 3.0 Professional exam and passed it successfully with 94%.

The aim of this post is to show you how, using CDI, you can inject Java properties entries (those in *.properties files) directly into your Java class.

If you want to remotely access your SSH account (e.g.

Did you know that you can compile Java source code from your running Java Application?

Whoa, those few days of GeeCON – Polish Java conference – just passed way too quick.

At the end of march 2012 I was attending a Spring 3 Core Training in Cracow which was organised by the SpringSource.

I must admit – I’m neither very experienced in the field of user interfaces nor really familiarised with all that JavaScript, jQuery stuff.

Sometimes you need to audit or profile your Java application.

I see a lot of people saying that: “there is only one instance of servlet per application”.

After one of the Ubuntu 11.10 updates I was affected by some really weird colors in the embedded flash player.

When you write your unit tests you must use some kind of assertions.

If you’re using Eclipse and working with a class with a lot of static members, you might be affected by the problem of lack of content assist and automatic import for such members.

If you’re interested in getting some basic information about Git, surely you already know about the Git Community Book – it’s undoubtedly a source of great knowledge.

I’m currently under the process of moving all my workplace repositories from SVN to Git (configured to work with Gerrit).

Sometimes you might be struggling with such error shown, e.g. in Eclipse: The method … must override a superclass method.

By default, Maven’s test plugin Surefire doesn’t scan files for @Test annotations, but rather takes only the files which class names ends with “Test” or “TestCase”.

I’ve had some problem with starting the GlassFish database.

Some time ago I’ve had a problem with SVN on my VirtualBox guest Ubuntu machine.

Some time ago I’ve posted about using multiple -exec options for find command which can be used to find in what JARs particular class lies.

Recently, I’ve bumped into few posts on StackOverflow where people tend to compare container managed EntityManager instances (so the one injected by the container) by invoking EntityManager#toString() method.

Sometimes you need to pass some additional / contextual data to the called EJB method.

If you’ve cloned a GitHub repository from the original one and not from your forked version and you would like to change it, you can just edit the .git/config file in your project and change the URL of the origin remote: [remote "origin"] fetch = +ref…

You probably know that if you use BMT (Bean Managed Transactions) you can get information about current transaction status by using UserTransaction interface (which implementation can be fetched either by JNDI or using dependency injection) and executing…

Once again Windows know exactly how to surprise me.

Just a note to myself – always check what classes are you importing in IDE, because if you see @Singleton in your class, it doesn’t mean it will work as a EJB Singleton.

If you want to execute a GUI based application on the remote server through SSH, you can achieve it quite easily using the ssh command.

Recently I needed to find out what GNU/Linux a terminal-only server is using.

If you want to add your classes (or any other resources) to your ShrinkWrap archive to a non-root location, you can use the following: @Deployment public static JavaArchive deploy() { // This is the classes and resources archive JavaArchive ar;…

When you create a deployment using Arquillian (great test runner for testing your Java EE code in the container of your choice: jBoss, Glassfish, OpenEJB, … either in embedded, managed or remote mode) remember that the name of the deployment archive file…

Just a letter to my future self: When you use Properties and creates the entries, remember to avoid the whitespaces.

Pretty useful thing about the Java classpath definition is that the wildcard (*) can be used in a replacement of all *.jar and *.JAR files in the specified directory.

I was trying to execute several commands on a single record found by the GNU/Linux find command.

I was trying to find a way to capture the network interface traffic on a remote server, just to see what (or who!)

It’s at least the third time I try to find a solution for the unavailable codecs proclem during rendering video project in Kdenlive.

The mock exam has been moved to a separate application working on the OpenShift and is available at exam.piotrnowicki.com.

If you’re using BASH find and want to find files which are named differently than the given pattern, you can use the following syntax: find .

Servlets 3.0 in Java EE 6, brings new interface called ServletContainerInitializer.

If you want to use new features of JSP >= 2.1 and EL, like deferred binding (the #{…} construction in EL), you’ll find that you cannot achieve it within a Tag File with implicit TLD generation.

Lately, after publishing the previous post, a friend of mine passed me a snipped of BigDecimal code.