2. Introductions  Two decades in software development  Software Engineering Solutions, Inc. www.swengsol.com www.swengsol.com  Technical Reviewer: Core JavaServer Faces 3 rd Edition  “Top 1000” reviewer at Amazon.com.

3. Why another Tomcat book?  Current focus is on administrators  Tend to view Tomcat as a black box  Exactly HOW does it do what it does?

4. Pieces of the Puzzle  Java EE  HTML over HTTP  Servlet Container.

5. Java EE

6. Uniform Resource Locators http://www.swengsol.com:80/myWebApp /adobe/invoices/EditInvoice ?id=x123;jsessionid=… schemeporthost context path servlet path info path parameters query string

7. HTML over HTTP

8. Servlet Specification  WAR file format  Servlet  Filter  Listener  Session  web.xml

9. Servlet Container Interaction

10. Concurrency

11. The Tomcat Servlet Container

12. Container Overview  A valve: Extends Tomcat functionality Is Tomcat-specific Must be super-efficient

13. Containment: Server and Service

14. Containment: Connectors

15. Containment: Catalina Engine

16. Containment: Virtual Host  Each FQHN resolves to a specific IP address  Needs dedicated IP addresses

17. Containment: Virtual Host  Multiple FQHNs resolve to a single IP address  Host: request header interrogated  Simple but requires help with SSL

18. Containment: Virtual Host

19. Containment: Context

20. Containment: Another View

21.  Benefits Late Binding (assembly of functionality) Security (single choke point) Customization (encrypt, generate, locate) Variance across Time Variance across Space Isolation Zones Advanced Topics: Java Class Loading First Principles

22.  Rules Consistency (always return same instance) Delegation (security) Visibility (Delegation hierarchy + CL inversion) Advanced Topics: Java Class Loading First Principles

23.  Available Options Implicit class loading: MyClass myClass = new MyClass() Explicit class loading: ClassLoader ldr = ClassLoader.getSystemClassLoader(); Class cls = ldr.loadClass("MyClass"); MyClass myClass = (MyClass) cls.newInstance(); Advanced Topics: Java Class Loading First Principles

24. Advanced Topics: Java Class Loading  No parent  Native code in JVM  Core Java classes from rt.jar  JRE_HOME/jre/lib/ext (implicit CLASSPATH)  Classes on CLASSPATH  Truncated by Tomcat  CATALINA_HOME/lib  Visible to web apps and Tomcat code  Directory configured in catalina.properties  Visible to all web apps  WEB-INF/classes and WEB-INF/lib  Delegates to parent for standard Java classes  Directory configured in [catalina.properties]  Visible only to Tomcat code  Lets you override core JDK classes  JAVA_HOME /lib/endorsed

25. Advanced Topics: Web Application Class Loading

26. Thank You!  damodarchetty@gmail.com  www.swengsol.com www.swengsol.com  651 270 8457 for training/consulting opportunities.