Spring MVC Controller与jquery ajax请求处理json

在用 spring mvc 写应用的时候发现jquery传递的【json数组对象】参数后台接收不到，多订单的处理，ajax请求：

var cmd =  {orders:[{"storeId":"0a1", "address":"西斗门路2号", "goods":[{"goodsId":"1"}, {"goodsId":"2"}, {"goodsId":"3"}]},{"storeId":"0a1", "address":"西斗门路2号", "goods":[{"goodsId":"4"}, {"goodsId":"4"}, {"goodsId":"5"}]}]}  
              
$.ajax({  
                url : url,  
                type : "POST",  
                datatype:"json",  
                data : cmd,  
                success : function(data, stats) {  
                    if (stats == "success") {  
                      //   window.location.href="/yc"  
                    }  
                },  
                error : function(data) {  
                    alert("请求失败");  
                }  
            });

开始如何传后台用 @RequestParam 去接收如何都接不到，分析下请求头，原来是json格式没转换

Origin:http://localhost  
Referer:http://localhost/test/myorder  
User-Agent:Mozilla/5.0 (Windows NT 6.1) AppleWebKit/537.1 (KHTML, like Gecko) Chrome/21.0.1180.89 Safari/537.1  
X-Requested-With:XMLHttpRequest  
Form Dataview URL encoded  
orders[0][storeId]:0a1  
orders[0][address]:西斗门路2号  
orders[0][goods][0][goodsId]:1  
orders[0][goods][1][goodsId]:2  
orders[0][goods][2][goodsId]:3  
orders[1][storeId]:0a1  
orders[1][address]:西斗门路2号  
orders[1][goods][0][goodsId]:4  
orders[1][goods][1][goodsId]:4  
orders[1][goods][2][goodsId]:5  
Response Headersview source  
Content-Length:1051  
Content-Type:text/html;charset=utf-8  
Date:Mon, 26 Nov 2012 16:10:07 GMT  
Server:Apache-Coyote/1.1

通过观察，orders[0][storeId]:0a1
orders[0][address]:西斗门路2号
orders[0][goods][0][goodsId]:1 变成了多维数组的格式传递，没有按json对象的方式传递（原以为 jquery会自动转的，可惜我想多了，所以出现了乌龙）。

下了个jquery的json插件，jquery.json-2.4.js 转了下json；但是问题又来了，传的格式正确但是后台还是接不到，打印了下request.getParameterMap(),参数按json格式传进来，但是接的方式又出现了问题，用string接肯定不行，String数组接也接不到，List也接不到，网上查查相关Controller的接收json对象的方式，需要用@RequestBody来进行接收，为了方便干脆把 orders去掉直接用json数组

var cmd =  [{"storeId":"0a1", "address":"西斗门路2号", "goods":[{"goodsId":"1"}, {"goodsId":"2"}, {"goodsId":"3"}]},{"storeId":"0a1", "address":"西斗门路2号", "goods":[{"goodsId":"4"}, {"goodsId":"4"}, {"goodsId":"5"}]}]

后台用

(@RequestBody List orders)

检查下参数写法，应该没错，测试之后还是有问题报了这样一个错误：
POST http://localhost/test/order 415 (Unsupported Media Type) 这个问题应该是前台请求过程中没有指明contentType，ajax中加上contentType: "application/json; charset=utf-8"，再测试，果然可以了。完整代码如下：
ajax：

var cmd =  [{"storeId":"0a1", "address":"西斗门路2号", "goods":[{"goodsId":"1"}, {"goodsId":"2"}, {"goodsId":"3"}]},{"storeId":"0a1", "address":"西斗门路2号", "goods":[{"goodsId":"4"}, {"goodsId":"4"}, {"goodsId":"5"}]}]  
              
$.ajax({  
                url : url,  
                type : "POST",  
                datatype:"json",  
                         contentType: "application/json; charset=utf-8",  
                data : $toJSON(cmd),  
                success : function(data, stats) {  
                    if (stats == "success") {  
                      //   window.location.href="/yc"  
                    }  
                },  
                error : function(data) {  
                    alert("请求失败");  
                }  
            });

Controller method:

@RequestMapping(value = "/order", method = RequestMethod.POST)  
 public  ModelAndView order(@RequestBody List<Map<String,Object>> orders) {  
        System.out.println("orders size:" + orders.size());  
}

以上希望能为遇到类似问题的朋友提供一些帮助。