Data access object (DAO) pattern is one of the core J2EE patterns used in many enterprise level applications. It provides a clean separation for various methods of data access and central point of access to data source.
Factory method is a creational design pattern widely used in many libraries and toolkits. It provides a unified interface to instantiate appropriate sub classes at runtime based on specific conditions.
Singleton design pattern ensures that only a single object is created even in multiple thread environments. It is a widely used design pattern in object oriented programming languages including Java.
There are many situations where we update multiple tables in a single transaction. In many cases you have to get the primary key value of the first record inserted in table 1 for updating/inserting record in second table. MySQL provides a handy function exclusively for this purpose.
Congratulations, you have developed and put your favourite web application in a hosting environment. Your application platform may be LAMP, .NET, J2EE etc. Suddenly your site is attracting large number of visitors and your system starts struggling to respond to all users! Here I explain some basic performance optimization techniques for all levels starting from design to hosting.
In this tutorial I am explaining some Linux admin commands I execute in my day to day life as developer.
Struts is a popular open source MVC framework for building dynamic web applications in Java platform which is now managed by Apache foundation. Struts 2 was evolved from Struts and WebWork, another Java web application framework from OpenSymphony.
Linux is a popular open source operating system originally developed by Linus Torvalds. Linux is almost similar to UNIX, another popular OS in many aspects. Here I am explaining some basic Linux commands which will be benefitted by developers in day to day life.
Lucene is an open source text based search engine orginally developed by Doug Cutting, now managed by Apache Software Foundation. It is a high performance easy to use API written purely in Java. Though it is written in Java platform, it is ported to many languages like PHP, C++ etc.
What do you mean by Filters? Filter is a component which intercepts HTTP request/response and provide additional functions. It is also used to modify request/response objects. Filters have been introduced since Servlet 2.3 specification. It act as a reusable component which could be attached to multiple resources like Servlets, JSPs etc and execute common tasks to them.