java - Spring MVC中不存在必需的字符串参数错误

我尝试在Spring MVC中对我的 Controller 进行AJAX查询。

我的 Action 代码是:

@RequestMapping(value = "events/add", method = RequestMethod.POST)
public void addEvent(@RequestParam(value = "start_date") String start_date, @RequestParam(value = "end_date") String end_date, @RequestParam(value = "text") String text, @RequestParam(value = "userId") String userId){
    //some code
}

我的Ajax查询是:

$.ajax({
        type: "POST",
        url:url,
        contentType: "application/json",
        data:     {
                start_date:   scheduler.getEvent(id).start_date,
                end_date:  scheduler.getEvent(id).end_date,
                text: scheduler.getEvent(id).text,
                userId: userId
        },
        success:function(result){
         //here some code
        }
    });

但是我得到一个错误:



为什么？
据我所知，它像(@RequestParam(value = "start_date") String start_date一样呈现

UDP
现在我给404
我类的数据

public class EventData {
    public String end_date;
    public String start_date;
    public String text;
    public String userId;
    //Getters and setters
}

我的js AJAX调用是:

$.ajax({
    type: "POST",
    url:url,
    contentType: "application/json",
    // data: eventData,
    processData: false,
    data:    JSON.stringify({
        "start_date":   scheduler.getEventStartDate(id),
        "end_date":  scheduler.getEventEndDate(id),
        "text": scheduler.getEventText(id),
        "userId": "1"
    }),

和 Controller Action :

@RequestMapping(value = "events/add", method = RequestMethod.POST)
public void addEvent(@RequestBody EventData eventData){
}

JSON数据是:

end_date: "2013-10-03T20:05:00.000Z"
start_date: "2013-10-03T20:00:00.000Z"
text: "gfsgsdgs"
userId: "1"

最佳答案

在服务器端，您希望将请求参数作为查询字符串，但在客户端，您将发送json对象。要绑定(bind)json，您将需要创建一个包含所有参数的类，并使用@RequestBody批注而不是@RequestParam。

@RequestMapping(value = "events/add", method = RequestMethod.POST)
public void addEvent(@RequestBody CommandBean commandBean){
    //some code
}

Here is更详细的解释。