[FIXED] How to bind form data into a model using Spring Boot?

Issue

I have this form:

<form action="/my-path" method="post">
    <div class="form-group">
        <label for="domain">Domain</label>
        <input class="form-control" id="domain" type="text" value="" name="domain">
        <label for="color">Color</label>
        <input class="form-control" id="color" type="text" value="" name="color">
    </div>
    <button class="btn btn-primary" type="submit">Filter</button>
</form>

which I'm trying to process in Spring MVC:

@PostMapping(
        path = ["/my-path"],
        produces = [MediaType.TEXT_HTML_VALUE])
public ResponseEntity<String> doSomething(ModelMap map) {
    // ...
}

but I just can't get this working, I see no data coming from the POST even when I fill the form with data and submit it.

I tried binding the values to my own dto:

@PostMapping(
        path = ["/my-path"],
        produces = [MediaType.TEXT_HTML_VALUE])
public ResponseEntity<String> doSomething(@RequestBody MyDto dto) {
    // ...
}

but in this case I get an exception because the method is unsupported (url encoded form). I'm at a loss here, I've tried 10 different ways to get the form data out of the request but it doesn't work, I either get exceptions or I get no data at all.

How do I make this pretty basic use case working with Spring Boot?

Solution

If you want to get all the request parameters in a map, you can add a @RequestParam Map parameter to the function, like this:

@PostMapping(
        path = ["/my-path"],
        produces = [MediaType.TEXT_HTML_VALUE])
public ResponseEntity<String> doSomething(@RequestParam Map allRequestParams) {
    // ...
}

If you want to get each form component in a different variable, you could use something like this:

@PostMapping(
        path = ["/my-path"],
        produces = [MediaType.TEXT_HTML_VALUE])
public ResponseEntity<String> doSomething(String domain, String color) {
    // ...
}

Spring automagically will bind the form inputs to your parameters matching the inputs 'id' attribute with the parameter names.

Answered By - jdmuriel