Spring MVC。 对Ajax的回应

In Spring MVC Application I have a controller and JSP file with Ajax. When I send data from Ajax to Spring Controller I have correct string with charset UTF-8 but when controller sends response to Ajax the encoding of this string is wrong. I need controller to send response in Russian and have this problem, when I have a response to Ajax and insert it to JSP page I have only: ?????? ????? ?????? .Here's my code:

@Controller
public class GroupsController {

@RequestMapping(value = "/addData.html", method = RequestMethod.GET)
public ModelAndView getPage() {
    return new ModelAndView("addData");
}

@RequestMapping(value = "/addData.html", method = RequestMethod.POST)
public @ResponseBody String addNewGroup(@ModelAttribute(value = "group") GroupStudent group,

    if(group.getGroupStudentNumber() != null) {
        return "Группа " + group.getGroupStudentNumber() + " добавлена";
     // return "Group " + group.getGroupStudentNumber() + " has been added"; 

    } else
        return null;

}

}


<%@ page language="java" pageEncoding="UTF-8" contentType="text/html; charset=UTF-8" %>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<%@ taglib prefix="form" uri="http://www.springframework.org/tags/form" %>
<html>
<head>  
    <title>Add data</title>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" charset="UTF-8">
    <script type="text/javascript" 
            src="<c:url value="resources/jquery.js"/>"></script>
    <script type="text/javascript">
        function addGroupAjax() {
            var groupStudentNumber = $('#groupStudentNumber').val();

            $.ajax({
                type: "POST",
                url: "/IRSystem/addData.html",
                data: "groupStudentNumber=" + groupStudentNumber,

                success: function(response) {
                    $('#group').html(response);
                },
                error: function(e) {
                    alert("Error" + e);
                }
            });
        } 
</script>
</head>
<body>
                <div align="left">
                    <label>Group</label>
                    <input id="groupStudentNumber"/>
                    <input type="submit" value="Add" onclick="addGroupAjax()" />
                    <div id="group" style="color:green"></div>
                </div>

</body>
</html>

You can set the encoding in the RequestMapping header like this...

@RequestMapping(value = "/addData.html", method = RequestMethod.GET, produces = "charset=UTF-8")

See if that helps.

It seems like your AJAX handler isn't reading the response body as UTF-8. I don't know why. You can try to force it by specifying the content type in the response generated by Spring. Change your return type

@RequestMapping(value = "/addData.html", method = RequestMethod.POST)
public ResponseEntity<String> addNewGroup(@ModelAttribute(value = "group") GroupStudent group, ...

    if(group.getGroupStudentNumber() != null) {
         HttpHeaders headers = new HttpHeaders();
         headers.add("Content-Type", "text/html; charset=utf-8");
         ResponseEntity<String> entity = new ResponseEntity<String>("Группа " + group.getGroupStudentNumber() + " добавлена", headers, HttpStatus.OK);
         return entity;
    } else
        return null;
}