ajax前后台交互

////////////////单个参数///////////////////

前台：

$("#operatecom").click(function(){

var id = $("#operatestate").val();

$.ajax({
        type: "POST",
        url: "${pageContext.request.contextPath}/testManage/testup",
        async: false,
        contentType: "application/json; charset=utf-8",
        data:id,
        dataType: "text",
        success: function (message) {
         alert(message)
        },
        error: function (message) {
        
        }
       });

});

------------------------------------------------------

后台：

@RequestMapping("/testManage/testup")

public void  auditExtractup(@RequestBody String id,HttpServletResponse response) {

　　String message = "";

　　if ("1".equals(id)) {

　　　　message = "操作成功";

　　} else {

　　　　message = "操作失败";

     }

　　PrintWriter out = null;

　　try {
        out = response.getWriter();
        out.print(message);
        out.flush();
      } catch (IOException e) {
         e.printStackTrace();
      } finally {
         if (null != out) {
           out.close();
         }
      }

 ////////////////多个参数///////////////////

前台：

function saveInfo(){
      var name = $("#name").val();
      var age = $("#age").val();
      var address = $("#address").val();
      
      $.ajax({
            type: "POST",
            url: "${pageContext.request.contextPath}/student/saveInfo",
            async: false,
            //contentType: "application/json; charset=utf-8",  -----------------注释掉这句话，否则控制层中获取不到参数值
            data:{name:name,age:age,address:address},
            dataType: "text",
            success: function (message) {
             alert(message)
            },
            error: function (message) {
            
            }
           });
  }

------------------------------------------------------

后台：

@RequestMapping("/student/saveInfo")
    public String saveInfo(HttpServletRequest request, Model model){
        String name = request.getParameter("name");
        String age = request.getParameter("age");
        return name;
    }