<form:options tag spring mvc binding

Question

I am binding a list with Spring MVC form select box like this given below

<c:forEach var="item" items="${instance.parameters}" varStatus="itemsRow">
    <form:select size="6" path="parameters[${itemsRow.index}].parmvalues" multiple="true">

        <form:options items="${item.pluginParmvalues}" itemValue="id" itemLabel="parmValue" />

    </form:select>
</c:forEach>

After binding this <form:select displays values correctly. But when I try to save it it throws exception. Should I also bind <form:options values to something like this

<form:options path="parameters[${itemsRow.index}].parmvalues[0].parmValue"

instead of items="${item.pluginParmvalues}" to get/save values in controller?

Exception:

Cannot convert value of type [java.lang.String] to required type [com.domain.Parmvalue] for property 'parmvalues[0]': no matching editors or conversion strategy found]

Answer 1

This way select box is not being bounded. You have to take a hidden field and bind that hidden field with path="parameters[${itemsRow.index}].parmvalues" . Each time select box value is changed. Change value of that hidden field too through javascript/jquery.