Required String parameter is not present error in Spring MVC

Question

I try to make an AJAX query to my controller in Spring MVC.

My action code is:

@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     } 

My Ajax query is:

$.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         }     }); 

But I got an error:

Required String parameter ''start_date is not present

Why? As I know I presented it like (@RequestParam(value = "start_date") String start_date

UDP
Now I give 404 My class to take data

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

My js AJAX call is:

$.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"     }), 

And controller action:

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

And JSON data is:

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

Answer 1

On the server side you expect your request parameters as query strings but on client side you send a json object. To bind a json you will need to create a single class holding all your parameters and use the @RequestBody annotation instead of @RequestParam.

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

Here is a more detailed explanation.