I am learning Spring Boot and using Thymeleaf in my project. When I replace the header code as a separate file in the same folder and use Thymeleaf's replace syntax, the CSS, JS, and Bootstrap code is not displayed on the website. When I try to run it on port 8080, only the HTML code is displayed without the CSS, JS, or Bootstrap.
log output error 2024-05-17T09:44:23.684+05:30 WARN 17192 --- [nio-8081-exec-1] actStandardFragmentInsertionTagProcessor : [THYMELEAF][http-nio-8081-exec-1][home.html] Deprecated unwrapped fragment expression "footer :: footer" found in template home.html, line 353, col 6. Please use the complete syntax of fragment expressions instead ("~{footer :: footer}"). The old, unwrapped syntax for fragment expressions will be removed in future versions of Thymeleaf.
this is the syntax i use


header.html- it has to have a fragment defined (e.g.<div th:fragment="header">) see thymeleaf.org/doc/articles/layouts.html