some basic queries regarding value stack in struts 2?

[scott miles]

I am new to strut 2 though I have worked on struts 1.2.In one of the pexisting project jsp file I have following code:

 <script type="text/javascript">
      var relationshipData = { //line1
          page : '<s:property value="displayPage" />',//line2
          records : '<s:property value="customerRelations.size" />',//line3
          rows : [<s:iterator value="customerRelations" status="iterStatus">//line4
      {id : '<s:property value="relationId" />', cell : ['<s:property value="relationDesc" escapeJavaScript="true" />']}<s:if test="!#iterStatus.last">,</s:if>//line5
    </s:iterator>]//line6
      };
      </script>

Request is coming CustomerRelationAction.java which has method getCustomerRelations() and getRelationId().

here are the questions :-
1.
I put breakpoint inside method getCustomerRelations().i see flow is coming four time inside this method. Two times at line 3 and another two times at line 4. As per my understanding flow should come only 1 time i.e at line 3. Once it completes getCustomerRelations at line 3 , should not put its value in value stack so that it can refer to it nextime it is refered (like it is being reffered at line 14 again)?

2.
getCustomerRelations() method returns the list of CustomerRelationData objects where CustomerRelationData class also contains the getRelationId() method.Now at line 5 we are refering value="relationId at line 5. On Which object(CustomerRelationAction.java or CustomerRelationData), getRelationId() method will be called? even i am not sure will the list object CustomerRelationData will be present on value stack or not?If yes at which line it will be put in value stack?

3.
Now the iterator completes at line 6.After that,now i refer the code <s:property value="relationId" /> again, On Which object(CustomerRelationAction.java or CustomerRelationData), getRelationId() method will be called?


posted at http://stackoverflow.com/questions/8930873/some-basic-queries-regarding-value-stack-in-struts-2 too but did not get any reply as of now.

[Mohana Rao Sv]

To see the data in the value stack put your project development environment

 <constant name="struts.devMode" value="true" />

and use the tag

<s:debug/>

in the jsp

[scott miles]

Mohan Rao Sv wrote:To see the data in the value stack put your project development environment

 <constant name="struts.devMode" value="true" />

and use the tag

<s:debug/>

in the jsp

Thanks for giving valuable information. But as soon as i do the above settings i see below error on web page

Struts has detected an unhandled exception: 

Messages: Stream closed 
 
File: org/apache/jasper/runtime/JspWriterImpl.java 
Line number: 204 


--------------------------------------------------------------------------------

Stacktraces
java.io.IOException: Stream closed 
    org.apache.jasper.runtime.JspWriterImpl.ensureOpen(JspWriterImpl.java:204)
    org.apache.jasper.runtime.JspWriterImpl.flushBuffer(JspWriterImpl.java:115)
    org.apache.jasper.runtime.JspWriterImpl.flush(JspWriterImpl.java:173)

Do i need to do some other other setting too for this? i am putting <s:debug /> tag after var relationshipData got evaluated i.e after }(see below line 6)

[Mohana Rao Sv]

Put this tag in form <s:debug/> or

http://localhost:8080/customersupport/yourAction.action?debug=xml

This will print the all the data in the valueStack.