SpringBoot enters the controller method to jump to the html, and the Whitelabel Error Page appears

First check whether you enter the controller method. The method
has been successfully called and the Whitelabel Error Page appears on the browser page
because there is no dependency on thymeleaf added to the pom.xml file.

<dependency>
	<groupId>org.springframework.boot</groupId>
	<artifactId>spring-boot-starter-thymeleaf</artifactId>
</dependency>