谁能解释一下thymeleaf的提交按钮在以下代码中是如何工作的?
<!DOCTYPE html>
<html lang="en" xmlns:th="http://www.thymeleaf.org"
layout:decorator="master">
<head>
<title>LoginPage</title>
</head>
<body>
<h1>Login Page</h1>
<!-- Any content you put in the div fragment below will appear on the page-->
<div class="container">
<div class="row">
<div class="span8">
<P th:if="${loginError}" >Wrong User or Password</P>
<form th:action="@{/new}" th:Object="${messageForm}"
method="post">
<label for ="User">User Name</label>
<input type="text" th:field="*{user}"/><br/>
<label for ="password">Password</label>
<input type="password" th:field="*{password}"/><br/>
<input type="submit" value="Login" />
</form>
</div>
</div>
</div>
</body>
</html>