CODEWITHSUNDEEP
formssessionstruts2arraylist
Angelina
Angelina

Reputation: 41

How to access a session ArrayList by index in a form?

I have a session variable which is of type ArrayList. In the jsp page I need to access it by index to create a form dynamically, but after I submit the form I found out that the session ArrayList's elements values didn't change.

Here it is what I've tried on my JSP page (I use struts2 Framework):

<s:iterator value="anotherArray" status="RowsIterator">
 <tr>
  <td>
   <s:iterator value="actionOptionsArray" status="iter">
    <s:radio
     name="#session.chosenActionsArray[%{#RowsIterator.index}]" <!-- The concerned line -->
     list="%{actionOptionsArray[#iter.index]}"
     value="#{actionOptionsArray[0]}"
     theme="simple" />
    <br>
   </s:iterator>
  </td>
  <!-- other fields--> 
 </tr>
</s:iterator>

anotherArray and #session.chosenActionsArray have the same size.

I guess I iterate it wrongly, but in my case iterating it by index is an obligation. Thank you a lot in advance :)

Upvotes: 3

Views: 390

Answers (1)

Quaternion
Quaternion

Reputation: 10458

You need to access the session via an action, the session is accessible from the jsp but not directly from the outside world in this way.

Have the action you are submitting the form to implement SessionAware. I would create a getter/setter for an ArrayList along with proper validation and then move those values into into the session via the execute method. I'm not a fan of exposing your session directly to the outside world (providing a setter for the session in your action)... if you do this you need to be aware that you may have given a malicious user access to things you might not have expected.

Edit

Suppose you have an ArrayList of ArrayList of String called "matrix" in your action... you can iterate the properties via:

<s:iterator value="matrix">
  <s:iterator>
    <s:property/>
  </s:iterator>
</s:iterator>

The outer iterator, iterates over "matrix" which pushes each instance to the top of the value stack. The inner iterator will use what is at the top of the stack by default same with the property tag. Placing tr's and td elements in the right place an you could render a table.

To generate the right name attribute for input elements (possibly hidden ones) you would want them in the form matrix[i][j] where i and j are integers and would define an appropriate matrix. Using status attribute of iterator as you've done would be a good way to generate the indexes.

Upvotes: 1

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