Can I use @Requestparam annotation for a Post request?

Question

I have this controller method:

@PostMapping(
        value = \"/createleave\",
        params = {\"start\",\"end\",\"hours\",\"username\"})
public void creat         


        

Answer 1

You should use @RequestBody instead of using @RequestParam And you should provide whole object as a body of request @RequestParam is to get data from URL

you can do something like public saveUser(@RequestBody User user) { do something with user }

and it will be mapped as User object for example

Answer 2

public void createLeave(@RequestParam Map<String, String> requestParams)

Above code did not work.

Correct syntax is:

public void createLeave(@RequestBodyMap<String, String> requestParams)

Answer 3

What you are asking for is fundamentally wrong. POST requests sends data in a body payload, which is mapped via @RequestBody. @RequestParam is used to map data through the URL parameters such as /url?start=foo. What you are trying to do is use @RequestParam to do the job of @RequestBody.

Alternative solutions for REST controllers

• Introduce a DTO class. It is the most preferred and clean method.
• If you really want to avoid creating a class, you can use @RequestBody Map<String, String> payload. Be sure to include 'Content-Type': 'application/json' in your request header.
• If you really want to use @RequestParam, use a GET request instead and send your data via URL parameters.

Alternative solutions for MVC controllers

• Introduce a DTO class and use it with annotation @ModelAttribute.
• If you transform the form data into JSON, you can use @RequestBody Map<String, String> payload. To do this, please see this answer.

It is not possible to map form data encoded data directly to a Map<String, String>.

Answer 4

Well, I think the answer by @Synch is fundamentally wrong, and not the question being asked.

1. First of all, I use @RequestParam in a lot of scenarios expecting either GET or POST HTTP messages and I'd like to say, that it works perfectly fine;
2. POST Message's data payload (body), which is referred to the most voted answer (again, by @Synch) is actually the text data, which can perfectly legally be paramname=paramvalue key-value mapping(s) alike (see POST Message Body types here);
3. docs.spring.io, an official source for Spring Documentation, clearly states, that:

   In Spring MVC, "request parameters" map to query parameters, form data, and parts in multipart requests.

So, I think the answer is YES, you can use @RequestParam annotation with @Controller class's method's parameter, as long as that method is request-mapped by @RequestMapping and you don't expect Object, this is perfectly legal and there's nothing wrong with it.

Answer 5

@PostMapping("/createleave")
public void createLeave(@RequestParam Map<String, String> requestParams){

    String start = requestParams.get("start");
    String end= requestParams.get("end");
    String hours= requestParams.get("hours");
    String username = requestParams.get("username");

    System.out.println("Entering createLeave " + start + " " + end + " " + hours + " " + username);
}

This is for multipart/form-data enctype post request.