title: 400 bad request,Is there any problem with the code in controller?
body: <p>I'm trying to send data to controller by ajax,but met with problem Failed to load resource: the server responded with a status of 400 (Bad Request).I don't know which part of the problem</p>
  
  <p>JS:</p>
  
  <pre><code>var info ={
          "questions":{"q1":trim(q1), "q2":trim(q2),"q3":trim(q3),"q4":trim(q4),"q5":trim(q5),"q6":trim(q6),"q7":trim(q7),"q8":trim(q8)},
          "answers":{"datetimepicker":datetimepicker,"sexual":sexual,"nation":nation, "province":province,"city":city, "sheng":sheng,"shi":shi,"xian":xian, "height":height,"weight":weight}
      };
      var info_str = JSON.stringify(info);
  $.ajax({
      type:'GET',
      data:info_str,
      contentType: "application/json; charset=utf-8",
      dataType: "json",
      url :'/yiban',
      success :function(data) {
          alert(data);
      },
      error :function(e) {
          alert("error");
      }
  });
  </code></pre>
  
  <p>Java:</p>
  
  <pre><code> @RequestMapping(value = "/yiban", method = RequestMethod.GET)
      public void yiban(HttpServletRequest request)
      {
          String jsonStr = request.getParameter("info_str");
          JSONObject questions = JSONObject.fromObject(jsonStr).getJSONObject("questions");
          JSONObject answers = JSONObject.fromObject(jsonStr).getJSONObject("answers");
          String q1 = questions.getString("q1");
          String ans = answers.getString("nation");
          System.out.println(q1);
      }
  </code></pre>