An introduction to Struts 2 and
RESTful applications
Don Brown
Atlassian
mrdon@twdata.org

What’s wrong with my web application?
 Modern web framework
 Presentation and business logic separation
 Code not tied to HTTP

Problem: Confusing URIs
GET
http://localhost/spaces/addspacenotification.action?
key=AJOBS
GET
http://localhost/spaces/addspacenotification.action?
key=AJOBS
GET
http://localhost/spaces/addspacenotification.action?
key=AJOBS
GET
http://localhost/spaces/addspacenotification.action?
key=AJOBS

Problem: Poor caching
HTTP traffic laws broken:
 GET - Could be anything,
including deletes and
updates
 POST - Also could be
anything, even regular
page views
 PUT - Not used
 DELETE - Not used

Problem: People can’t get at their data

REST is the Way of the Web

Not just for Web Services
http://www.flickr.com/photos/psd/2217422218/

Solution: Humane URIs
GET
http://localhost/spaces/addspacenotification.action?
key=AJOBS
POST
http://localhost/spaces/AJOBS/notifications
GET
http://localhost/spaces/AJOBS/notifications/3
PUT
http://localhost/spaces/AJOBS/notifications/3
DELETE
http://localhost/spaces/AJOBS/notifications/3

Solution: Scalable caching
Follow HTTP traffic laws:
 GET - No side-effects, can
repeat
 POST - Changes state,
cannot repeat
 PUT - Changes state, can
repeat
 DELETE - Changes state,
can repeat

Solution: One API for all

REST in action

Detour: Struts 2

Struts 2 History

Struts 2 plugins

Struts 2 Codebehind Plugin
http://example.com/myapp/public/profile.xhtml
Calls:
com.example.myapp.actions.public.ProfileAction
Forwards to:
/WEB-INF/jsp/public/profile.jsp

Struts 2 REST Plugin
URI HTTP Method Action Method
/orders GET index()
/orders/3 GET show()
/orders POST create()
/orders/3 PUT update()
/orders/3 DELETE destroy()
/orders/new GET editNew()
/orders/3/edit GET edit()

A RESTful example: orders
. . . Let’s see some code!

REST in the real world

Not everything is a resource
Account:
• GET . . . Yep
• POST . . . Yep
• PUT . . . Yep
• DELETE . . . Yep
• Renew?

Account Renewal: resource or operation?
Renew as a Resource
POST:
http://localhost/accounts/3/renewals
Renew as an Operation
POST
http://localhost/accounts/3/renew

REST is training friendly

WS-* REST
XML HTTP
WSDL XML *
XML Schema
SOAP
AXIS/CXF V.S.
JAXB
WS-Security*
UDDI*

Clients are and aren’t free
But not

REST: the silver bullet?

The takeaway: apply REST to your app

Questions?
http://struts.apache.org/2.x/docs/rest-plugin.html