disabled="disabled" Is used to disable the first options in the select dropdown in spring form below is the example
<sf:select class="select form-control-lg" path="type">
<option selected="true" disabled="disabled">Select Leave Type</option>
<sf:option value="CL" label="CL"/>
<sf:option value="PL" label="PL"/>
<sf:option value="SL" label="SL"/>
</sf:select>
Disable input into the spring form
readonly="true"An attribute will disable any input field into the spring form.
<sf:input readonly="true" type="text" id="email" class="form-control form-control-lg" path="email" name="email" value="${sessionScope.user.email}"/>
Retrieve Dynamic list
<sf:select class="select form-control-lg" path="scheduleWith">
<option selected="true" disabled="disabled">Select Schedule With</option>
<c:forEach var="userType" items="${userTypeList}">
<sf:option value="${userType.firstName}" label="${userType.firstName}"/>
</c:forEach>
</sf:select>