Java EE (formerly known as J2EE) is a suite of technologies used to create enterprise grade applications. The technologies which form part of Java EE include JNDI, JMS, EJB, Servlets, JSP, JSF, JPA etc. The advantage of using Java EE is that there are servers like IBM WebSphere and Oracle WebLogic which are Java EE complaint. This means that porting an application from one server to another requires comparatively less effort.

java_ee

Java EE Web Application Concepts

How session tracking works
HTTP is stateless protocol then how to track users. Java EE provides mechanism for session tracking using session id.

load-on-startup tag in web.xml
The use of load on startup tag is to improve the performance of web application by performing any initialization early in the application.

What is a filter
Using a Filter in Java based web application is a good practice as it reduces the burden of performing common tasks from individual servlets.

ServletConfig and SevletContext
web.xml provides initialization parameters for whole application and each servlet separately. How to use ServletConfig and ServletContext to access these values.

How to avoid Session Fixation
Tutorial on how to perform Session Fixation in Java web application. Avoid hacking attacks in a web server. Configure server for improving security.

GET and POST requests
The use of GET and POST methods in the HTTP protocol. How do GET and POST differ from other HTTP methods like DELETE,PUT etc.

Performance Management in web applications
A list of steps to be taken when designing and developing the application so as to improve the performance and decrease user waiting time.Nice tutorial on web.

Servlets

Enable gzip in Tomcat and WAMP
Gzip standard compresses the content which is then converted to text by browser. Apache Tomcat and WAMP support Gzip out of the box.

Why no constructor is defined in Servlet
There are multiple reasons for not having constructor defined in a web service. A very good interview questions answered here

Sending character response from Servlet
How to send character data as response to a request in Java web server code. Character stream, content type and code in Java servlet.

Understanding Servlet Life Cycle
The three life cycle methods of Java servlets are invoked at different times in an application.Each method has its own importance in the life cycle.

Map Servlet and JSP to URL
The web.xml file can be used to map JSP to a particular URL so that you get rid of .jsp at the end of default URL’s for JSP files in a Java web application.

JSP

What are the various JSP Implicit Objects
JSP implicit objects are convenient shortcuts of commonly required objects like session, request,out and exception etc. Understand the concept behind them.

Adding JSP Comments
There are multiple types of comments already present in Java applications like javadoc, HTML comments then what different is JSP comment. Read More.

Understanding JSP Lifecycle
Similar to servlets, JSP also has life cycle phases where different methods are invoked during creation, execution and finalization of JSP code.

Java EE Complaint Servers

Configure Hot Deployment in Tomcat, JBoss,WebLogic
Configure hot deployment in Java web and application servers like Tomcat, WebLogic and GlassFish. Steps for adding automatic change detection in code.

Books

Top 10 Java EE books
JAVA EE is vast and their are huge number of books catering to different aspects. Some recommendations from Java Experience for you.