Articles having tag: CORE JAVA

Java Timer

When there is a need to trigger a task automatically based on time we should schedule it using a timer api. The requirement can vary from a single execution on a fixed time to high complex recurring event. For example take our regular alarm clock where we fix...

System.out.println

By Joe

It is love at first type. I fell in deep love with it from the first moment I used it. Didn’t you? How many times have we used it till now? It is one of the most number of times compiled statement in the history of java. We fondly call it SOP. If you...

ThreadLocal

By Joe

Core concept of ThreadLocal is, “every thread that accesses a ThreadLocal variable via its get or set method has its own, independently initialized copy of the variable”. In other words, we want to have separate instances(private copy) of a class...

Java Iterator

By Joe

To generate successive elements from a series, we can use java iterator. It is an improvement over Enumeration interface. Iterator takes the place of Enumeration since jdk 1.2 It is a nice utility for collections. Every collection is unique on its own and imagine...

Semaphores Using Java

By Joe

Semaphore is an interesting topic in operating systems and it can be used in a variety of ways to solve challenging problems. In this article I will explain, what is a semaphore how to implement a semaphore in java an example problem and solution implementation...

Eclipse Shortcuts

By Joe

Editors are an integral part of a programmer’s life. If you have good proficiency in using an editor thats a great advantage. It comes very handy to debug. Traditional notepad and SOPs (System.out.println) are the way we start learning a language but...

Java Class Loader

By Joe

Java ClassLoader loads a java class file into java virtual machine. It is as simple as that. It is not a huge complicated concept to learn and every java developer must know about the java class loaders and how it works. Like NullPointerException, one exception...

JVM Shutdown Hook

By Joe

Java JVM provides you a hook to register a thread with the shutdown initiation sequence. Once a thread is registered, on every shutdown that thread is run. JVM’s shutdown sequence has two phases. All registered shutdown hooks are started in some unspecified...

Externalizable vs Serializable

By Joe

Externalizable is an interface that enables you to define custom rules and your own mechanism for serialization. Serializable defines standard protocol and provides out of the box serialization capabilities. Externalizable extends Serializable. Implement writeExternal...

serialVersionUID in Java Serialization

By Joe

serialVersionUID is used to ensure that during deserialization the same class (that was used during serialize process) is loaded. This is a one line definition to explain why a serialVersionUID is used? Apart from the above definition there are quite \xa0a...