This document discusses containers in Java applications. It begins by introducing containers and describing lightweight and heavyweight containers. It then discusses who uses containers and why, including reasons like centralized configuration, security, performance, and clustering. The document questions whether containers are needed for single applications and discusses alternatives like running applications directly on HTTP servers or writing your own web server. It advocates for simplicity and flexibility over full Java EE containers. It concludes by encouraging questions and providing contact information for further discussion.

1. Who Needs
Containers
Anyway?
Dmitry Buzdin
Java User Group Latvia

2. Today we will talk
about containers...

3. Java is all about
containers, right?

4. Lightweight
Container

5. Heavyweight Container

6. Enterprise
Container

7. Who uses
containers?

9. Why do you use
them?

10. I use Container
Because:
• <Reason 1>
• <Reason 2>
• <Reason 3>
• <Reason 4>
• <Reason 5>
• <Reason 6>

11. Data and Code Integrity
Centralized Configuration
Security
Performance
Total Cost of Ownership
Transaction Support
http://en.wikipedia.org/wiki/Application_server

12. Thread Management
Log Management
Hot Redeploys
Application Monitoring
Distributed Environment
Clustering
Multiple Apps on one Server

13. What if you have only
one application?

14. multiple apps
centralized configs
hot-redeploys
distributed environment

15. Can I live without the
container?

16. Should I write my own
Web Server?

17. Perhaps not.

19. Http Server Only
Supports Servlets
Runs Spring

22. Used in Play! and
Elastic Search

23. Grizzly

24. Supports Servlets
and more...

25. Simple - Jetty
Extensible - Netty
Oracle - Grizzly

26. We can start an app
without the container!
... so what?

27. Simplicity
Flexibility
Performance
Development Speed

28. Why now?

29. Browser
GET/POST HTML
Server
JSP Servlet

30. Browser
JQuery
GET/POST JSON
Server
REST

31. Browser
GET HTML
Server

32. Browser
AJAX
GET JSON WEB SOCKETS
Server

33. 1 user != 1 thread

34. Browser
GET JSON

35. Browser
QUEUE

36. Java NIO
Event-Driven Asynchronous
Non-Blocking

37. Back to Client-Server

38. Your app should
run in Jetty

39. The world is async

40. JAR
Ignore JavaEE*
* if you can

41. Questions

42. References
http://jetty.codehaus.org/jetty/
http://netty.io/
http://grizzly.java.net/

43. Recognized these words?
Write to
dmitry@livesheets.com
for the next steps