Archive for the ‘J2EE’ Category

Lot of times I have been asked by users on this site to write tutorial about Struts 2 Framework. My previous tutorial on Creating Struts Application in Eclipse is one of the most viewed article on this site. So lets begin Part 1 of 7-parts series tutorials on Struts 2 Framework. In these tutorials we will discuss ... Full story

Lot of time when I am working in Eclipse, it get crashed due to some or the other reasons. Most of the time this is because I have opened a lot of applications that I am working on and this takes a bit of memory. So finally everything just get hanged and does not have enough RAM to work on. Thus, Eclipse just get hanged ... Full story

Recently while running Tomcat under Eclipse for one of the web application I was getting Java Heap memory related error java.lang.OutOfMemoryError. What needs to be done here basically is to increase the jvm heap size. So for increasing the JVM Heap Size of Tomcat in Eclipse we have to set few VM arguments of the tomcat. Follow ... Full story

Yesterday while working on one of the old web application that was created in J2EE / JSP which is using JSTL for painting pages, I encountered a wired issue. As I was using JSTL in my JSPs, I had include required jars like standard.jar and jstl.jar with proper version in classpath of my project. Still I was getting this error whenever I tried running JSP: According ... Full story

Database Connection Pooling is a great technique used by lot of application servers to optimize the performance. Database Connection creation is a costly task thus it impacts the performance of application. Hence lot of application server creates a database connection pool which are pre initiated db connections that can be leverage to increase performance. Apache Tomcat ... Full story

A lot of time we want to run multiple instances of Apache Tomcat server on a single machine. Generally this is done for creating a separate load balancer server for an application or install a different application independently. This can be achieved easy by some configuration in Tomcat Server. We need to install a second instance ... Full story

Following is the basic overview of Apache Archiva, The Build Artifact Repository Manager. What is Archiva? Apache Archiva is an extensible repository management software that helps taking care of your own personal or enterprise-wide build artifact repository. It is the perfect companion for build tools such as Maven, Continuum, and ANT. Features of Archiva Remote repository proxying Security access ... Full story

Listener is one of the most popular technologies used in the J2EE web application. It is part of the Java Servlet as defined in Servlet 2.3 but they have their own specific functionalities. There are two most widely used Servlet Listener i.e. ServletContextListener and HttpSessionListener. Let us create a Servlet Listener that just counts the number of running http sessions and prints the details whenever a ... Full story

Implementing Logout functionality in a form based authentication in J2EE website is straight forward. The session needs to be invalidated by calling request.getSession().invalidate() method. Thus in a simple servlet following code will be the code for logout: public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { request.getSession().invalidate(); response.sendRedirect("/sampleapplication/index.jsp"); } This is simple way for implementing logout. There is also another, ... Full story

For a quite while I had been using Ant build tool for building my Java projects. Since few days I have been switching to Apache Maven, an open source build framework that can be used to build almost all the projects in Java, .Net and other platforms. Maven was created by Sonatype's Jason van Zyl in ... Full story