Dynamically Populate Drop down List In Spring MVC

I am new to Spring MVC. I have two Dropdown Lists in Jsp.One for country and Other for State. As soon as i select country from list State list should be populated with respective lists.

My ajax Program:

$("select#country").change(function() {
var val=$("#country").val();
alert(val);
$.ajax(
url : 'getstates',
method : 'get',
contentType: 'application/json',
data :
country : val
,

success: function (data)
alert("Success Response"+ data);

,

error :function()

alert("error");


);


My Controller Program:

public @ResponseBody HashMap<String, String>
showstates(@RequestParam(required = false, value = "")
String country,@Valid @ModelAttribute("employee")Login employee,
BindingResult result, ModelMap model)
HashMap<String,String> statelist = new HashMap<String,String>();
List<States> statelist = new ArrayList<States>();
if (country.equals("UnitedStates"))
statelist.put("Al","Alaska");
statelist.put("Tl","Texas");
else if (country.equals("India"))
statelist.put("Mh","Maharashtra");
statelist.put("WB","West Bengal");
statelist.put("KR","Karnataka");
statelist.put("AP","Andhra Pradesh");
statelist.put("TN","Tamil Nadu");

return statelist;



I am not getting the response from controller. How to access the hasmap in jsp. Please Help me. Thanks.

2 Answers
2

I think you should change your method like below.

@RequestMapping(value = "/getstates", method = RequestMethod.GET)
public @ResponseBody HashMap<String, String> showstates(@RequestParam(required = false, value = "")
String country,@Valid @ModelAttribute("employee")Login employee,
BindingResult result, ModelMap model)
HashMap<String,String> stateMap = new HashMap<String,String>();
//put your logic to add state on basis of country

return stateMap;



Then on JSP you can simply iterate this map,like below.

<c:forEach items="$state.stateMap" var="data" varStatus="status">
<tr>
<td>$data.value</td>
</tr>
</c:forEach>


shearing my solution. because i was stuck in same condition.

html page

$(document).ready(function() // for client name

$('#example').change(function(event)
var country = $("select#example").val(); // country = define value of selected option
$.getJSON('ajaxAction0',
ptype : country
, function(data)
var select = $('#clientname');
select.find('option').remove();
$.each(data, function(key, value)
$('<option>').val(key).text(value).appendTo(select);
);
);
);
);

<div>
<select class="form-control" name="example" id="example">
<option value="0">ALL</option>
<option th:each="dropdown : $dropdown" th:value="$dropdown.id"
th:text="$dropdown.tagName"></option>
</select> <select class="form-control" name="clientname" id="clientname">
<option value="0">ALL</option>
<option th:each="dropd : $drpdwn" th:value="$dropd.id"
th:text="$dropd.tagName"></option>
</select>
<button id="w-button-search" type="button">Search</button>
</div>

controller code for first drop down

@RequestMapping(value = "/dropdown", method = RequestMethod.GET)
public String dropDown(Model model)
List<Tag> data = new ArrayList<>();
data.add(new Tag(1, "ruby"));
data.add(new Tag(2, "rails"));
data.add(new Tag(3, "c / c++"));
data.add(new Tag(4, ".net"));
data.add(new Tag(5, "python"));
data.add(new Tag(6, "java"));
data.add(new Tag(7, "javascript"));
data.add(new Tag(8, "jscript"));
model.addAttribute("dropdown", data);
return "dropDown";



second drop down code is

Map <string, string> udata = null;
@RequestMapping(value = "ajaxAction0", method = RequestMethod.GET)
public @ResponseBody Map<String, String> findAllAgencies(
@RequestParam(value = "ptype", required = true) String ptype)
udata = new HashMap<>();
EntityManager em = entityManagerFactory.createEntityManager();
em.getTransaction().begin();
List<UserRecord> user = em
.createNativeQuery("Select id, name, email from user_Record where id = :uid", UserRecord.class)
.setParameter("uid", ptype).getResultList();
for(UserRecord ur:user)
udata.put(ur.getEmail(), ur.getName());

return udata;


hope it will help.

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