I have configured default settings in this spring boot thymeleaf crud example tutorial so the application.properties file is not required. We can improve the example by adding Comments for each Tutorial. Spring MVC Controller The controller class has URL mappings and its handler methods. We just focused on Thymeleaf in Spring Boot project. We will need a very simple business layer for our application. Clicking the "id" and "name" link will lead us to Contact Page, and clicking the "edit" link will lead to Edit Contact Page. Thymeleaf able to process HTML, XML, Javascript, CSS, even plain text. If you want to use MySQL database or other stuff to configure then you should use application.properties file. In my spare time, I love to travel, take photos, and exploring new technology, Spring Boot + JPA/Hibernate + PostgreSQL RESTful CRUD API Example, Spring Boot RESTful Web Services CRUD Example, Documenting Spring Boot REST API with Swagger, Spring Boot + Groovy Templates CRUD Example, SpringFox Bean Validators for Swagger Documentation. th:field calls RequestDataValueProcessor.processFormFieldValue() for rendering the value of the field it applies to (or the tag body if it is a