src/main/resources/templates/layout/default_layout.html

<!DOCTYPE html>
<html xmlns:th="http://www.thymeleaf.org"
      xmlns:layout="http://www.ultraq.net.nz/thymeleaf/layout">

    <head>
        <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
        <title>&gt;**&lt;</title>
        
        <!-- config fragment 사용 -->
        <th:block th:replace="fragment/config :: configFragment" ></th:block>
    </head>
    
    <body>
        <!-- header fragment 사용 -->
        <th:block th:replace="fragment/header :: headerFragment"></th:block>
        
        <!-- 
            content fragment 사용 
            현재 layout을 사용하는 content fragment의 내용을 삽입한다.
        -->
        <div  style="height: calc(100% - 8em);">
	        <th:block layout:fragment="content"></th:block>
        </div>
        
        <!-- footer fragment 사용 -->
        <th:block th:replace="fragment/footer :: footerFragment"> </th:block>
    </body>

</html>