Core java

In this tutorial,  we are going to see differences between Serializable and Externalizable interface in Java. Java Serialization Tutorial: Serialization in java Java Serialization interview questions and answers serialversionuid in java serialization externalizable in java Transient keyword in java Difference between Serializable and Externalizable in Java Before understanding difference, let me provide a short note on Serializable […]

In this tutorial, we will see how to check if number is power of two. There are many approaches to check if number is power of two or not. Approach 1: It is very easy and straight forward approach. Run a while loop which checks for condition if n is even number (n%2==0). If n is […]

Callable interface represents a thread that can return a value. It is very much similar to Runnable interface except that it can return a value. Callable interface can be used to compute status or results that can be returned to invoking thread. For example: Let’s say you want to perform factorial and square of some […]

Synchronization is ability to restrict access to shared resource to only one thread. When two or more threads need access to shared resource, there has to be some mechanism such that shared resource will be used by only one thread. The process by which we can achieve it is called Synchronization. Why do you need […]

Exchanger class is introduced with java 1.5 with other classes such ConcurrentHashMap, CountDownLatch, Semaphores. Exchanger class is used to exchange object between two threads. Exchanger simply waits until two separate threads calls exchange method, when it happens, it exchanges data supplied by threads.Two threads can pair and swap objects between them. Exchanger class may be useful […]

1. Introduction Java’s Executors.newCachedThreadPool() factory method provides a thread pool that creates new threads as needed, but will reuse previously constructed threads when they are available. Our goal is to understand how to use this thread pool to execute asynchronous tasks efficiently. 2. What is newCachedThreadPool? The newCachedThreadPool method from the java.util.concurrent.Executors class is a […]

Java 5 has introduced new concurrent API called Executor frameworks to make programmer life easy. It simplifies design and development of multi-thread applications. It consists of mainly Executor, ExecutorService interface and ThreadPoolExecutor class which implements both interfaces i.e. Executor and ExecutorService. ThreadPoolExecutor class provide the implementation of thread pool. We will understand more about it […]

In this tutorial, we are going to see about Semaphore in java. Semaphore is a class in java.util.concurrent package introduced in JDK 5. Semaphore basically maintains a set of permits, so there are two methods which are mainly used for semaphore. acquire release acquire() method is used to get a permit and if no. of […]

In this post, I am going to share java interview questions which are generally asked on immutable class. Immutable class is important topic as it deals with creation of thread safe class. Here I am providing some important immutable class interview questions with answers. 1. What is immutable class? Answer : Immutable objects are those […]