How to read yaml file then display the result in localhost by using springboot?

You can use Jackson to map YAML to Java Objects. For Spring Boot create a controller with a / GET Mapping and return your html (or use Spring MVC together with a template).

Those resources might be usefull:

• Jackson: https://stackabuse.com/reading-and-writing-yaml-files-in-java-with-jackson/
• Spring Controller: https://spring.io/guides/gs/spring-boot/
• Spring MVC: https://docs.spring.io/spring-framework/docs/3.2.x/spring-framework-reference/html/mvc.html