jsp - Collect and save submitted values of multiple dynamic HTML inputs back in servlet -

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i able display arraylist of beans in jsp form using jstl looping through list , outputting bean properties in html input tag.

<c:foreach items="${listofbeans}" var="bean">   <tr>     <td><input type="text" id="foo" value="${bean.foo}"/></td>       <td><input type="text" id="bar" value="${bean.bar}"/></td>                        </tr> </c:foreach>

how code jsp when page submits updated values in appropriate item of the arraylist?

given simplified model:

public class item {     private long id;     private string foo;     private string bar;     // ... }

here's how can provided ${items} list<item>:

<c:foreach items="${items}" var="item">     <tr>         <td>             <input type="hidden" name="id" value="${item.id}" />             <input name="foo_${item.id}" value="${fn:escapexml(item.foo)}" />         </td>           <td>             <input name="bar_${item.id}" value="${fn:escapexml(item.bar)}" />         </td>     </tr> </c:foreach>

(note importance of fn:escapexml() xss attack prevention)

so, basically, need set item's unique identifier hidden input field in each row shown in above snippet:

<input type="hidden" name="id" value="${item.id}" />

and should in turn use id suffix of name of input fields in same row such as:

<input name="foo_${item.id}" ... />

in servlet, can collect values of <input type="hidden" name="id" ...> rows request.getparametervalues(). loop on , grab individual inputs id.

for (string id : request.getparametervalues("id")) {     string foo = request.getparameter("foo_" + id);     string bar = request.getparameter("bar_" + id);     // ... }

you can without id , grab inputs name array name="foo" , request.getparametervalues("foo"), ordering of request parameters not under control. html forms send in order, enduser can manipulate order.

no need javascript mess here.

see also:


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