Question

我想将一个Spring对象的List返回给一个AJAX请求。

AJAX请求：

function doAjaxPost(date) {
    $.ajax({
        type : "POST",
        contentType : "application/json",
        url : "<%="/water-consumer" + homepageURL + "/hourConsumption"%>",
        data : date,
        dataType : 'json',
        success : function(response) {
            if(response != null)
                showHourConsumption(response);
        }
    });
}

Spring控制器：

@RequestMapping(value = "/{username}/hourConsumption", method=RequestMethod.POST, produces="application/json")
public @ResponseBody List<HourConsumption> getHoursConsumptions(@RequestBody String day, HttpSession session, Model model) {
    // do something ....
    Household household = (Household)session.getAttribute("household");
    List<HourConsumption> consumptions = this.mrs.getHoursConsumption(household.getSmart_meter().getOid(), day);
    // do something 

    if(consumptions == null) //check if what get back from something is not null
        return null;
    else
        return consumptions; 
}

现在，AJAX请求正确，所以我收到来自控制器的请求并生成正确的消耗（列表）但是当它返回List时，浏览器会给我回复以下内容错误：

无法加载资源：服务器响应状态为406 （不可接受）

有人可以告诉我，我该怎么做或正确的方法呢？非常感谢你！

Answer 1

一些指示：

http方法可以是GET iso POST。
删除会话和模型参数。如果您需要会话，则可以从自动装配HttpServletRequest。
确保你有杰克逊作为依赖

Answer 2

确保类路径中存在以下2个jar。

如果缺少任何一个或两个，则会出现此错误。

jackson-core和jackson-mapper

Answer 3

问题在于您返回的数据，浏览器没有很好地形成JSON。然后我会从你的Controller中删除属性“产生”，并保留Spring Jackson变换器来创建json实体。

将您的代码更改为：

@RequestMapping(value = "/{username}/hourConsumption", method=RequestMethod.POST)
public @ResponseBody List<HourConsumption> getHoursConsumptions(@RequestBody String day, HttpSession session, Model model) {
    // do something ....
    Household household = (Household)session.getAttribute("household");
    List<HourConsumption> consumptions = this.mrs.getHoursConsumption(household.getSmart_meter().getOid(), day);
    // do something 

    if(consumptions == null) //check if what get back from something is not null
        return null;
    else
        return consumptions; 
}

Answer 4

尝试使用Google的gson（https://mvnrepository.com/artifact/com.google.code.gson/gson）将Json格式字符串发送到页面。

Spring Controller

@RequestMapping(value = "/{username}/hourConsumption", method=RequestMethod.POST)
public @ResponseBody String getHoursConsumptions(@RequestBody String day, HttpSession session, Model model) {
    String jsonFormatData = "";
    // do something ....
    Household household = (Household)session.getAttribute("household");
    List<HourConsumption> consumptions = this.mrs.getHoursConsumption(household.getSmart_meter().getOid(), day);
    // do something 


    // **Using Gson**
    // You can include this in your bean definition and autowire it
    // and use the singleton created by Spring.
    // For this example I am instantiating Gson myself
    Gson gson = new Gson(); 

    jsonFormatData = gson.toJson(consumptions);

    return jsonFormatData; 
}

从Spring控制器返回一个Object List到AJAX请求

4 个答案: