Cant change column value by pressing button (Spring Boot, Thymeleaf)

Question

I get an Request method 'POST' not supported error every time I press the button

EventController.java fragment

@PostMapping(value = "/ledger/{id}/get-place")
public String modifyLedger(@PathVariable(value = "id") long id, @RequestParam Long place, Model model) {
    Event event = eventRepository.findById(id).orElseThrow();
    event.setPlace(place - 1);
    eventRepository.save(event);
    return "ledgerInfo";
}

That function suppose to substract 1 from Long place variable every time when i press the button but every time i got an HttpRequestMethodNotSupportedException error

LedgerInfo.html

<div class = "container mt-5">
    <h1>Ledger Info</h1>
    <div th:each="elem:${event}" class="alert alert-info mt-2">
        <h2 th:text="${elem.title}"/>
        Line count:<p th:text="${elem.line}"/>
        Place remain:<p th:text="${elem.place}"/>
        Place status:<p th:text="${elem.status}"/>
        <form method="post">
            <button type="submit" class="btn btn-success">Get Place</button>
        </form>
    </div>
</div>

Have no idea how to fix this. Any clues?

Answer 1

You did not specified the action for your form. Use th:action="@{/your Url}" in the form tag.