对于以下方法，JSONObject始终为空。

 @RequestMapping(value = "/package/{id}", method = RequestMethod.PUT)
@ResponseStatus(HttpStatus.OK)
@ResponseBody
public SPackage updatePackage(@PathVariable String id, @RequestBody JSONObject   
 sPackage) {
}

我的ajax就是这样 我正在将对象作为服务器端的空映射

   var jsonObject= {"customerName":$('#customerName').val()}
     var jsonData = JSON.stringify(jsonObject);  
            $.ajax({ 
                type: "PUT",
                url: "http://localhost:8081/someproj/package/" + $('#id').val(),
                dataType: "json",
                data: jsonData,
                async: false,                                               
                contentType: "application/json; charset=utf-8",
                beforeSend : function() { 
                    openModal();
                },
                success: function(data) { 
                    closeModal();
                $('#success').show();
                 console.log(data);
                }
            });