Home » Author Archives: Jakub Kubrynski

Author Archives: Jakub Kubrynski

I'm software developer by vocation. Java team leader at work and open source enthusiast at home. Strongly interested in new technologies. Fan of java.util.concurrent and sun.misc.Unsafe. My motto is "minimum code, maximum functionality.

Using jstat to report custom JVM metric sets

java-logo

I’ve always been missing possibility to configure custom headers in JStat. Of course there are a lot of predefined data sets, but it’ll be nicer if we could create our own data set. And as you probably already devised I’m writing this post because such functionality is of course available :) Unfortunately I haven’t found it in any documentation so ...

Read More »

Dependency injection pitfalls in Spring

spring-interview-questions-answers

There are three injection variants in Spring framework: Setter-based injection Constructor-based injection Field-based injection Each of those mechanisms has advantages and disadvantages and there is not only one right approach. For example field injection:      

Read More »

Need micro caching? Memoization to the rescue

java-logo

Caching solves wide sort of performance problems. There are many ways to integrate caching into our applications. For example when we use Spring there is easy to use @Cacheable support. Quite easy but we still have to configure cache manager, cache regions, etc. Sometimes it’s unfortunately like taking a sledgehammer to crack a nut. So what can we do to “go lighter”? ...

Read More »

Debugging OpenJDK

openjdk-logo

Sometimes debugging Java code is not enough and we need to step over the native part of Java. I spent some time to achieve proper state of my JDK to do that, so short description probably will be useful for ones starting their trip. I’ll use the brand new OpenJDK 9! At first you have to obtain main repository by ...

Read More »

Understanding Spring Web Initialization

spring-interview-questions-answers

Few years ago majority of us were used to write XML config files everywhere, to setup even simple Java EE application. Today using Java or Groovy to configure projects is becoming preferred way – you just need to take a look at Gradle or functionalities introduced in further versions of the Spring Framework to gen up on this. Now I’ll ...

Read More »

Injecting Spring beans into non-managed objects

spring-interview-questions-answers

Advantages coming from dependency injection can be addicting. It’s a lot easier to configure application structure using injections than doing all resolutions manually. It’s hard to resign from it when we have some non-managed classes that are instantiated outside of the container – for example being part of other frameworks like Vaadin UI components or JPA entities. The latter are ...

Read More »

Using HA Singleton in JBoss 7

jboss-logo

Some time ago I had to change standard clustering behavior of Quartz Scheduler, and let it work without synchronizing over database. There are of course a lot of options to do that, but because I’m big fan of simplicity I’ve decided to use standard Spring @Scheduled configuration and totally skip thinking about cluster at this level. The idea was to ...

Read More »

Speed Up with Fast Java and File Serialization

java-logo

Since the first version of Java, day-by-day many developers have been trying to achieve at least as good of performance as in C/C++. JVM vendors are doing their best by implementing some new JIT algorithms, but there is still a lot to do, especially in how we use Java. For example, there is a lot to win in objects<->file serialization ...

Read More »

Java 7 vs Groovy 2.1 Performance Comparison

java-logo

I haven’t used Groovy for 2 years, since my last touch with Grails. I get stuck in (hard)core Enterprise Java, with some performance aspects in background. I’ve almost missed a chance to learn Spock, but fortunately Warsaw Java User Group helped me to snap out of some legacy systems and back to normal self-development. In fact I hope that frameworks ...

Read More »
Do you want to know how to develop your skillset and become a ...

Subscribe to our newsletter to start Rocking right now!

To get you started we give you our best selling eBooks for FREE!
Get ready to Rock!
To download the books, please verify your email address by following the instructions found on the email we just sent you.

THANK YOU!

Close