java - thymeleaf submit button code -

Can anyone explain how to use the Timileff button to work in the following code? Submit?

  & lt ;! DOCTYPE html & gt; & Lt; Html lang = "en" xmlns: th = "http://www.thymeleaf.org" layout: decorator = "master" & gt; & Lt; Top & gt; & Lt; Title & gt; LoginPage & lt; / Title & gt; & Lt; / Head & gt; & Lt; Body & gt; & Lt; H1 & gt; Login page & lt; / H1> & Lt ;! - You place any content in a piece below - will appear on the page - & gt; & Lt; Div class = "container" & gt; & Lt; Div class = "row" & gt; & Lt; Div class = "span8" & gt; & Lt; Pth: if = "$ {loginError}" & gt; Wrong user or password & lt; / P & gt; & Lt; Form th: action = "@ {/ new}" th: object = "$ {messageForm}" method = "post" & gt; & Lt; Label = "user" & gt; Username & lt; / Label & gt; & Lt; Input type = "text" th: field = "* {user}" /> gt; & Lt; Br / & gt; & Lt; Label = "password" & gt; Password & lt; / Label & gt; & Lt; Input type = "password" th: field = "* {password}" /> gt; & Lt; Br / & gt; & Lt; Input type = "submit" value = "login" /> & Lt; / Form & gt; & Lt; / Div & gt; & Lt; / Div & gt; & Lt; / Div & gt; & Lt; / Body & gt; & Lt; / Html & gt;    
 
 
 All of the following can be found in this page.  
 By the first look, I can say that  & lt; Form & gt;  The template is provided as a standard form with a 
 POST  call when you submit.  
 This is not more than plain http / html What is added by the structure that the form field is dynamically bound to an underlying object, which is  th: object = "$ {messageForm}"  is referred to by attribute.  
 Each field is calculated by calling a method on  th: field = "* {password}"  syntax with  messageForm  object .  
 Finally, the post call is created, the URL created by evaluating  th: action = "@ {/ new}"  attribute, possibly relative to the current page.  
 
 We make an example to clarify. Suppose we have  
 
 one object  messageForm  type  MessageForm  
  user  Type  string   
  password  type  string   
 providing the template URL  "Http://my.app.com/login"    
 with a web page, what you get from submitting a button is that The  message format  will have its properties in the  user  and  password  Set the values ​​that are kept in the respective fields of that form, and call a  "http://my.app.com/new"  page from the form, or similarly,  Message Form  to check the credentials for the login operation from the object ...  
 
 If you do not already, then I strongly advise you to read Before the thymeleaf website.