JSPs allow you to write html, css, javascript etc. just as if you were writing an html file.  JSPs can be considered as html pages (except for the .jsp extension and some extra lines) with some java code inside.  JSPs may also contain no Java at all. In this example we will create our first JSP page, deploy it on Apache Tomcat and then runt it.

Prerequisites

• JDK (1.7 or more)

• Eclipse IDE (Mars or more)

Filters are pluggable classes that stand between the client and a target component (like a servlet or JSP), within a web application. We can do pre or post processing of request/response data while it is coming from client to a servlet or from the servlet back to a client. 

Create a Servlet TargetServlet with URL Pattern as “/TargetServlet” and print some content to console from its doGet method. Code for TargetServlet is given in the end.

Now create a filter that will have the same url pattern for the servlet.

RequestDispatcher mechanism used for forwarding to and including other resources. We will understand the basics of RequestDispatcher mechanism using a simple exercise.

Before proceeding, you need to configure your eclipse and tomcat. I am using eclipse Eclipse Java EE IDE for Web Developers version: Luna and Apache Tomcat version 8.0.18. Apache Tomcat version 8.0.18 support Servlet Spec 3.1, JSP Spec 2.3, EL Spec 3.0, WebSocket spec 1.1 and support java version 7 and above.

We will download, install and configure gradle, and then execute a simple program.

Prerequisites

1. Gradle 1.x requires a Java JDK 5 or higher to be installed and the location needs to be added to an environment variable JAVA_HOME. 

2. Gradle 2.x requires a Java JDK 6 or higher to be installed and the location needs to be added to an environment variable JAVA_HOME. 

We will write a simple JavaFX application that displays a “Hello World” button. We will handle any button click events to print “Hello World” in the console. The program can be run from command line or from an IDE like eclipse, but without the Eclipse Plugin for JavaFX and Scene builder.