This document provides an overview and setup instructions for introducing servlets. It discusses: 1) What a servlet is - a Java program that runs on a server and processes incoming web requests and responses based on a URL. 2) Installing Tomcat, the Java web server, and Eclipse, the IDE, to develop and run servlets. 3) Creating a basic "Hello World" web application with a servlet using Eclipse, and deploying it to Tomcat.

1. 01-Overview-and-SetupDhrubojyotiKayal

2. Introducing ServletsInstalling Tomcat Installing EclipseYour first Java web applicationYour first ServletAgenda

3. Static HTML is so boring! – Dynamic content with ServletsA Java program that runs on a server. Follows a standard specification.Standard way to register servlet.Current version 3.0 (JSR 315)We focus on 2.5 (JSR 154) as 3.0 is very newServer forwards incoming request – headers, form data to registered servlet based on URL.Servlet processes data, generates new data and passes back to the server which in turn forwards it to the browserWhat is a servlet?

4. In ActionServletRDBMSBrowserServletServerJVM

5. EfficientUses threads not OS processes, one servlet instanceConvenientHigh level utility functionsPowerfulData processing, pooling, persistencePortableRuns on any OS where you get JVMInexpensiveBest in class open source servers to run servletsAdvantages

6. SecureNo hazards related to process managementPopularMost popular use of Java technologyMedium for large web apps of the scale of Google search Supported byApache, IBM, Oracle, Jetty, Coucho …..Runs onWindows, Unix, MacOS, VMS, IBM Mainframe OSUsed forAll kinds of applications – airline, hotels, banking, insurance …..Advantages

7. Hands On Exercise

8. Java web serverServlet reference implementationhttp://tomcat.apache.orgTomcat 7 – Servlet 3Tomcat 6 – Servlet 2.5DownloadInstallRunSee the web admin consoleShutdownTomcat

9. Eclipse IDE (http://www.eclipse.org)Open Source and supported by all biggies in Java businessEclipse 3.5 - GalileoBased on plug-in and OSGi coreFew essential plug-ins Install EclipseRun EclipseShutdown EclipseEclipse IDE

10. Setup new Tomcat 6 serverStart ServerStop ServerSetup Tomcat on Eclipse

11. Create workspaceCreate web application using EclipseThe project structure in EclipseNeed for web.xmlConfigure Tomcat 6 in EclipseWhat is deployed? – war fileStructure and contents of a blown up war fileManual deployment on TomcatDeploy using admin consoleFirst Web Application

12. Ah this web application does nothingLet us create the first servlet on EclipseWhat has changed on the web.xmlDeployWhat changes in the exploded war?Lets send a request for our servletHurray it respondsFirst servlet

13. Q&A