SpringSecurity, it was found that the page in
controller could not be recognized. The page was placed under
templates. After starting springboot, it was found that the request could not locate the specified page, and a 500 error was reported.
I found that I forgot to introduce the
thymeleaf module dependency when I created the project
<!--thymeleaf--> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-thymeleaf</artifactId> </dependency>