Saturday, March 23, 2019

Difference between Stable and Unstable Sorting Algorithm - MergeSort vs QuickSort

Recently in one on the interview, after some initial questions about sorting algorithms e.g. how do you write QuickSort or difference between QuickSort and MergeSort, the interviewer asked about do you understand the difference between stable and unstable sorting algorithm? This question was new to my reader, so he says, Sorry, never heard about that. The story ended there, and Interviewer moved on to next question but like many of us, my reader went on to find more about unanswered questions and ultimately he asks me what is the meaning of a stable and unstable sorting algorithm? Some of you might be heard about it and many of you might not know about this distinction, I'll try to answer this question in this article.

Wednesday, March 6, 2019

Spring Hello World Example in Java using Dependency Injection and XML Configuration

Hello All, In this Spring framework tutorial, you will learn how to write the hello world example in the Spring framework. This should be your first tutorial to start learning Spring framework, as it gets the ball rolling. While coding and running this example, you learn a lot about Spring framework, Spring XSD files, necessary JAR files, and more importantly how Spring framework works. This HelloWorld program in Spring framework is an extension of the classical Java hello world program, which you might have seen earlier. This program is written using the Dependency Injection design pattern by using the Spring Framework's IOC container.  Even though now you can configure Spring dependency using annotations and Java configuration, this example uses a traditional XML way to configure dependencies.

Tuesday, March 5, 2019

How to deal with java.lang.ClassNotFoundException: org.springframework.web.servlet.DispatcherServlet in Spring Application

The java.lang.ClassNotFoundException: org.springframework.web.servlet.DispatcherServlet error comes when you deploy a Spring MVC application into Tomcat or Jetty and Servlet container not able to found this class, which usually found in the spring-webmvc.jar file. The DispatcherServlet is the core of Spring MVC framework, it implements the FrontController pattern and intercept all HTTP requests sent to your Web application and subsequently route it to correct controller based upon URL mapping.