Yakov Fain

GlassFish, Open MQ, and the Ear-Eye Problem Yesterday I’ve been updating code examples for the messaging chapter for the 2nd edition of my Java book. While doing this, I ran into an issue, then fixed it, but the cause and the solution illustrate the situation that we call “Ear-Eye”, which comes from and old joke popular in the USSR, where TV propaganda was stating that everything is great while people had hard time finding food in store. Here’s the joke: An old lady comes to a medical center saying that she needs to see an Ear-Eye specialist. The receptionist replied, “There is no such specialization in medicine. Why would you need such a doctor?” The old lady answered, “What I hear on the radio, I don’t see in the real life.” In programming, we have similar situations quite often – you look at the code everything looks perfect, but it doesn’t work no matter how long... (more)

Java Is Short For JavaScript. Not! By @YFain | @ThingsExpo [#IoT]

Here’s  is a quote from the About page of the Web site ehow.com: “eHow is your one-stop online resource for life’s challenges. Professionals in every field come together to offer expert advice, backed by the additional support of a can-do eHow community.“ Experts are also human beings and sometimes they make mistakes too. But when I’ve read the following article I was stunned: Guys and girls, I’m not an eHow-grade expert, but I’ve been doing both Java and JavaScript for while. Trust me, the above description is absolutely wrong! Please ignore. Also, if you know any of the 35 peop... (more)

What’s the Difference Between Abstract Classes and Interfaces?

Probably the most popular question during Java technical interviews is “What’s the difference between abstract classes and interfaces”.  In my own three year old book I’ve offered the following answer: “An abstract class may contain code in method bodies, which is not allowed in an interface.With abstract classes you have to inherit your class from the abstract one because Java does not allow multiple inheritance. On the other hand, you can implement multiple interfaces in your class.” But starting from Java 8 this answer is wrong. This is how I’d answered it now: “Both abstract... (more)

JavaFX Event Handling and Property Binding

Some time ago I blogged that Java Swing should be deprecated and replaced with JavaFX. In this blog I’ll show a piece of JavaFX namely event handlers and binding. I’ve created a simple Sign In window with a GridPane layout (it’s JavaFX equivalent of Swing’s GridBagLayout). I’m not going to spend much time on the GridPane itself, but will show you a basic event handling and a binding. In JavaFX an event object is represented by the instance of the class javafx.event.Event. There are different ways of handling events. Depending on how you structured your application you can handle... (more)

Closures in Java with Lambdas

While working on the second edition for my Java 24-hour Trainer book I’m re-writing some of the code samples to use lambda expressions. Today I was re-writing an example for wait/notify for the chapter on multi-threading. Beside illustrating the wait/notify, I used a closure in this example. Since Java closures are not well presented in the blogosphere, I decided to write a quick blog on the subject. My goal was to write a program that starts a thread and waits for the notification from that thread until its execution is completed. When the main thread receives the notification ... (more)