When developing a WEB application using Spring Boot, the screen is actually displayed at localhost: 8080. At that time, I was skipped to the mysterious login page without transitioning to the expected html file.
When I look it up, it seems to come out when using Spring Security.
If it is the default setting, the user name is `" user "`, and if you enter the password displayed on the console when Spring Boot starts, you will be logged in and you will reach the target page.
* If you don't use Spring Security, just delete the dependency and it's OK!
Reference: Spring Boot project shows the login page p>