Do you want to know how to develop your skillset to become a Java Rockstar?

Subscribe to our newsletter to start Rocking right now!

To get you started we give you our best selling eBooks for FREE!

1. JPA Mini Book

2. JVM Troubleshooting Guide

3. JUnit Tutorial for Unit Testing

4. Java Annotations Tutorial

5. Java Interview Questions

and many more ....

 

Android Fragment transaction: FragmentManager and Backstack

android-logo

Fragments are useful when we want to support multiple screen size. To manage fragments we need a FragmentManager that help us to handle trasaction between fragments. With transaction we mean a sequence of steps to add, replace or remove fragments. In the last post we showed how to support multiple screen size and orientation using fragments. Now we want to go a ...

Read More »

Guava’s EventBus – Simple Publisher/Subscriber

java-logo

Looking over recent additions to Google’s Guava Libraries Release 10 I noticed the addition of EventBus. This is a lightweight implementation of a publish-subscribe style messaging system. This is similar to the publish-subscribe model provided by JMS, however the messages remain within the application rather than being broadcast externally. EventBus allows you to create streams within your program to which ...

Read More »

Clojure macros for beginners

clojure-logo

This article will guide you step-by-step (or even character-by-character) through the process of writing macros in Clojure. I will focus on fundamental macro characteristics while explaining what happens behind the scenes. Imagine you are about to write an assertions library for Clojure, similar to FEST Assertions, ScalaTest assertions or Hamcrest. Of course there are such existing but this is just ...

Read More »

Setting up Apache Hadoop Multi – Node Cluster

apache-hadoop-logo

We are sharing our experience about Apache Hadoop Installation in Linux based machines (Multi-node). Here we will also share our experience about different troubleshooting also and make update in future. User creation and other configurations step – We start by adding a dedicated Hadoop system user in each cluster.       $ sudo addgroup hadoop $ sudo adduser –ingroup hadoop ...

Read More »

Android ListView context menu: ActionMode.CallBack

android-logo

In this post we want to analyze the context menu (contextual action bar). This is a menu that is related to a specific item. The contextual menu can be applied to almost all views but it is usually used with ListView. We talk a lot about List view, because it is one of the most important component. We can distinguish ...

Read More »

Running Map-Reduce Job in Apache Hadoop (Multinode Cluster)

apache-hadoop-logo

We will describe here the process to run MapReduce Job in Apache Hadoop in multinode cluster. To set up Apache Hadoop in Multinode Cluster, one can read Setting up Apache Hadoop Multi – Node Cluster. For setting up we have to configure the hadoop with the following in each machine: Add the following property in conf/mapred-site.xml in all the nodes ...

Read More »

Java EE CDI programmatic dependency disambiguation example – Injection Point inspection

java-interview-questions-answers

In this tutorial we shall see how we can avoid programmatic dependency disambiguation when injecting Java EE CDI beans. We have already shown in the Jave EE dependency disambiguation example how to avoid dependency disambiguation in CDI beans. Here we shall show you how to avoid dependency disambiguation in a dynamic way. We will achieve this by inspecting the injection ...

Read More »

Reducing memory consumption by 20x

java-logo

This is going to be another story sharing our recent experience with memory-related problems. The case is extracted from a recent customer support case, where we faced a badly behaving application repeadedly dying with OutOfMemoryError messages in production. After running the application with Plumbr attached we were sure we were not facing a memory leak this time. But something was ...

Read More »

MongoDB to CSV

mongodb-logo

Every once in a while, I need to give a non-technical user (like a business analyst) data residing in MongoDB; consequently, I export the target data as a CSV file (which they can presumably slice and dice once they import it into Excel or some similar tool). Mongo has a handy export utility that takes a bevy of options, however, ...

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