java.lang.IllegalArgumentException: Attribute 'items' must be an array, a Collection or a Map - spring

Question

i am trying to make simple spring mvc application, using jdbctemplate,but when i try to open registration page i got this error- java.lang.IllegalArgumentException: Attribute 'items' must be an array, a Collection or a Map.
last time i used this thing in another applicaton, it worked fine,but this time it is not working :(
here is my controller code and register.jsp
#RequestMapping("/register")
public ModelAndView registerEmployee(#ModelAttribute Employee employee) {
List<String> cityList = new ArrayList<String>();
cityList.add("kashipur");
cityList.add("moradabad");
cityList.add("delhi");
cityList.add("noida");
List<String> genderList = new ArrayList<String>();
genderList.add("male");
genderList.add("female");
Map<String,List<String>> map = new HashMap<String,List<String>>();
map.put("cityList",cityList);
map.put("genderList",genderList);
return new ModelAndView("register","map",map);
}
register.jsp is
<div>
<form:form method="post" action="/insert" modelAttribute="employee">
<table>
<tr>
<td>Name :</td>
<td><form:input path="name" /></td>
</tr>
<tr>
<td>Gender :</td>
<td><form:radiobuttons path="gender" items="${map.genderList}" /></td>
</tr>
<tr>
<td>City :</td>
<td><form:select path="city" items="${map.cityList}" /></td>
<tr>
<tr>
<td>Email :</td>
<td><form:input path="email" /></td>
</tr>
<tr>
<td>Phone :</td>
<td><form:input path="phone" /></td>
</tr>
<tr>
<td><input type="submit" value="Save" /></td>
</tr>
<tr>
<td colspan="2"><a href="getList">Click Here to See User
List</a></td>
</tr>
</table>
</form:form>
</div>

Answer 1

Try to change this List<String> cityList
to this ArrayList<String> cityList
same here
Map<String,List<String>> map = new HashMap<String,List<String>>();
Also try to access map element like this map['cityList']

Answer 2

You don't need to qualify with ${map.
Simply write
return new ModelAndView("register", map);
and in the JSP:
<td><form:radiobuttons path="gender" items="${genderList}" /></td>
and
<td><form:select path="city" items="${cityList}" /></td>