2. JDK and JRE
What is this PATH variable?
Servers and Containers
Eclipse
Creating a web project using Eclipse – JSP
3. Java is the language – Library + Platform
◦ Java Card
◦ Micro Edition
◦ Standard Edition
◦ Enterprise Edition
JDK is the library
◦ The set of classes & tools (javac, java)
JRE is the platform
◦ VM that executes Java bytecode.
◦ How does the JVM know where the classes are?
4. Environment variables – Named values that affect
the way running processes behave.
◦ Provides a standard way for accessing commonly used
processes.
◦ Eg: Temp files, Java
Where could we see the list of all ENV vars?
CRUD on ENV variables.
PATH – Specifies a set of directories where
executable programs are located.
◦ Order of search – Current working directory PATH
variable (left to right)
◦ Sample – Batch script
%CLASSPATH%
5. Servers serve the requests from other programs.
Depending on the computing service
◦ Database server
◦ File server
◦ Mail server
◦ Web server!
◦ Application server
6. Web server – Deliver webpages on request from
clients. Eg: Apache, IIS, Nginx
General usage : A web browser / web crawler
initiates communication by making request to a
specific resource, server responds with content of
that resource (HTML Document)
Features :
◦ Virtual Hosting
◦ Bandwidth Throttling – fair share
◦ Server side scripting
8. Modularization!
An interface between the component and the low-
level-platform specific functionality.
Eg: Web Container, EJB container
Web Container (Servlet container) Web servers
◦ Interacts with the servlets
Roles of Web Container
◦ Lifecycle of servlets
◦ Mapping a URL to a servlet
◦ Access rights to an URL
9. Web server (with a web container)
Difference between apache and apache tomcat.
◦ Apache is C
◦ Tomcat is Java
Tomcat is configurable – server.xml
Three Components
◦ Catalina – servlet container
◦ Coyote – HTTP Connector Component
◦ Jasper – JSP Engine (converts JSP files to servlets for Catalina)
Check Tomcat server startup.
Latest version in Tomcat 7.0.26
10. Web Servers + Java EE concepts
Security, Data Services, Transaction Support,
Persistence Support, Load Balancing etc.
Eg: WebLogic Oracle, IBM WebShere
Check JBoss AS
12. Exercise : Quiz website
Time : 15 mins
Completion : Not mandatory