Request method 'POST' not supported - spring-boot

Question

I have a spring-Boot application, and
I am trying to send an object using post method to the below controller:
#PostMapping("/suggestevent")
public String receiveSuggestedEvent(#ModelAttribute SuggestedEvent event) {
return "redirect:/suggestEvent";
}
but it complains with:
There was an unexpected error (type=Method Not Allowed, status=405).
Request method 'POST' not supported
So, what is wrong?
Update:
I have tried this and it also did not work
#RequestMapping(value = "/suggestevent", method = RequestMethod.POST)
The form contains some simple inputes, and a select, which works based on Thyemeleaf. Here is my form:
<form th:action="#{/suggestevent}" method="post">
<div class="form-group">
<label for="title">Title</label>
<input type="text"
class="form-control" id="title" placeholder="Event title"
th:value="${event.title}"
name="title" required="required"/>
</div>
<div class="form-group">
<label for="mainFouce">Main Focus</label>
<input type="text"
class="form-control" id="Focus" placeholder="Focus"
th:value="${event.mainFouce}"
name="Focus" required="required"/>
</div>
Event Type
<div class="form-group">
<select class="form-control" name="type" th:value="${event.type}">
<option value="volvo">Party</option>
<option value="saab">Workshop</option>
<option value="fiat">Friendship</option>
</select>
</div>
<div class="form-group">
<label for="city">Area</label>
<input type="text"
class="form-control" id="area"
th:value="${event.area}"
placeholder="Berlin, Estonia ,or even Asia" name="area"
required="required"/>
</div>
<div class="form-group">
<label for="description">Description</label>
<textarea name="description" class="form-control"
th:value="${event.description}"
required="required" form="usrform"
placeholder="What makes it an special event?"></textarea>
</div>
<button type="submit" class="btn btn-default">Submit</button>
</form>
The sent object is:
#Entity
#Data
public class SuggestedEvent {
#Id
#GeneratedValue
Long id;
String title;
String mainFouce;
EventType type;
String area;
String description;
}
The postman can successfully reach the controller, but the thyemeleaf complains!!!

Answer 1

What happens when you try to add an empty SuggestedEvent object inside the form and try to populate that object like so:
<form th:action="#{/suggestevent}" th:object="${event}" method="post">
<div class="form-group">
<label for="title">Title</label>
<input type="text"
class="form-control" id="title" placeholder="Event title"
th:value="*{title}"
name="title" required="required"/>
</div>
<div class="form-group">
<label for="mainFouce">Main Focus</label>
<input type="text"
class="form-control" id="Focus" placeholder="Focus"
th:value="*{mainFouce}"
name="Focus" required="required"/>
</div>
Event Type
<div class="form-group">
<select class="form-control" name="type" th:value="*{type}">
<option value="volvo">Party</option>
<option value="saab">Workshop</option>
<option value="fiat">Friendship</option>
</select>
</div>
<div class="form-group">
<label for="city">Area</label>
<input type="text"
class="form-control" id="area"
th:value="*{area}"
placeholder="Berlin, Estonia ,or even Asia" name="area"
required="required"/>
</div>
<div class="form-group">
<label for="description">Description</label>
<textarea name="description" class="form-control"
th:value="*{description}"
required="required" form="usrform"
placeholder="What makes it an special event?"></textarea>
</div>
<button class="btn btn-default">Submit</button>
</form>
And in the #GetMapping("/suggestEvent"):
#GetMapping("/suggestEvent")
public String getSuggestEventPage(Model model) {
model.addAttribute("event", new SuggestEvent());
return "suggestEventPage";
}
Check out the official Thymeleaf doc otherwise. This shouldn't really be a problem, since I am doing the exact same thing in my project.
http://www.thymeleaf.org/doc/articles/standarddialect5minutes.html
http://www.thymeleaf.org/doc/articles/springmvcaccessdata.html
http://www.thymeleaf.org/documentation.html