Introductory presentation to action-based Java MVC framework Struts 2.

1. Introducing Struts 2 JaMU 07.02 – February 24, 2007 Thomas Wiradikusuma (thomas@wiradikusuma.com) Java User Group Indonesia

5. Architecture, cont’d

7. Interceptors <interceptor-stack name=&quot;xaStack&quot;> <interceptor-ref name=&quot;thisWillRunFirstInterceptor&quot;/> <interceptor-ref name=&quot;thisWillRunNextInterceptor&quot;/> <interceptor-ref name=&quot;followedByThisInterceptor&quot;/> <interceptor-ref name=&quot;thisWillRunLastInterceptor&quot;/> </interceptor-stack> thisWillRunFirstInterceptor thisWillRunNextInterceptor followedByThisInterceptor thisWillRunLastInterceptor MyAction1 MyAction2 (chain) MyPreResultListener MyResult (result) thisWillRunLastInterceptor followedByThisInterceptor thisWillRunNextInterceptor thisWillRunFirstInterceptor

8. Interceptors, cont’d Checks for valid token presence in Action, prevents duplicate form submission. token Token And many more… Action will only be executed if the user has the correct JAAS role. roles Roles If the Action implements Preparable, calls its prepare method. prepare Prepare Sets the request parameters onto the Action. params Parameters Executes the Action in the background and then sends the user off to an intermediate waiting page. execAndWait Execute and Wait Adds automatic checkbox handling code that detect an unchecked checkbox and add it as a parameter with a default (usually 'false') value. Uses a specially named hidden field to detect unsubmitted checkboxes. checkbox Checkbox Description Name Interceptor

10. Results Used for Velocity integration Velocity And many more… Used for Action Chaining Chain Used to stream an InputStream back to the browser (usually for file downloads) Stream Used to redirect to another action mapping Redirect Action Used to redirect to another URL (web resource) Redirect Used for web resource integration, including JSP integration Dispatcher Usage Result

13. Configuration files Override the default Velocity configuration /WEB-INF/classes/ Yes velocity.properties Optional configuration files for plug-ins in the same format as struts.xml. Root of a plug-in JAR Yes struts-plugin.xml Default macros referenced by velocity.properties /WEB-INF/classes/ Yes struts-default.vm Default configuration provided by Struts /WEB-INF/lib/struts2-core.jar Yes struts-default.xml Framework properties /WEB-INF/classes/ Yes struts.properties Main configuration, contains result/view types, action mappings, interceptors, and so forth /WEB-INF/classes/ Yes struts.xml Deployment descriptor /WEB-INF/ No web.xml Purpose Location Optional? File

14. Taglib <% User user = ActionContext.getContext() %> <form action=&quot;Profile_update.action&quot; method=&quot;post&quot;> <table> <tr> <td> align=&quot;right&quot;><label>First name:</label></td> <td><input type=&quot;text&quot; name=&quot;user.firstname&quot; value=&quot;<%=user.getFirstname() %> /></td> </tr> <tr> <td> <input type=&quot;radio&quot; name=&quot;user.gender&quot; value=&quot;0&quot; id=&quot;user.gender0&quot; <% if (user.getGender()==0) { %> checked=&quot;checked&quot; %> } %> /> <label for=&quot;user.gender0&quot;>Female</label> ... Without taglib (JSP): <s:actionerror/> <s:form action=&quot;Profile_update&quot; validate=&quot;true&quot;> <s:textfield label=&quot;Username&quot; name=&quot;username&quot;/> <s:password label=&quot;Password&quot; name=&quot;password&quot;/> <s:password label=&quot;(Repeat) Password&quot; name=&quot;password2&quot;/> <s:textfield label=&quot;Full Name&quot; name=&quot;fullName&quot;/> <s:textfield label=&quot;From Address&quot; name=&quot;fromAddress&quot;/> <s:textfield label=&quot;Reply To Address&quot; name=&quot;replyToAddress&quot;/> <s:submit value=&quot;Save&quot; name=&quot;Save&quot;/> <s:submit action=&quot;Register_cancel&quot; value=&quot;Cancel&quot; name=&quot;Cancel&quot; onclick=&quot;form.onsubmit=null&quot;/> </s:form> With taglib (JSP):

20. Struts 1 to Struts 2 Despite the similar name (Struts), migrating from Struts 1 is harder than migrating from WebWork 2. struts.xml struts-config.xml Action or POJO ActionForm Action or POJO Action (singleton) {action}-validation.xml validation.xml Result ActionForward Interceptors RequestProcessor FilterDispatcher ActionServlet Struts 2 Struts 1

21. WebWork 2 to Struts 2 Pretty much the same, only naming/namespace changes. <s:*/> <ww:*/> struts.xml xwork.xml struts.properties webwork.properties com.opensymphony.xwork2.* com.opensymphony.xwork.* “ struts” “ webwork” org.apache.struts2.* com.opensymphony.webwork.* Struts 2 WebWork 2