This exception indicates that the URL of the jump page has no corresponding value

Reason 1:

The location of the application startup class is incorrect. Put the application class on the outermost side, that is, it contains all sub packages
reason: spring boot will automatically load all components under the package where the startup class is located and its sub packages

Reason 2:

In the springboot configuration file: application.yml or application.properties, about the configuration of the view parser:
when the spring boot starter paren version in the POM file is higher:
spring.mvc.view.prefix/spring.mvc.view.suffix
when the spring boot starter paren version in the POM file is low, use:
spring.view.prefix/spring.view.suffix

Reason 3:

URL path writing problem of controller
@RequestMapping(“xxxxxxxxxxxxxx”)
the actual access path does not match “XXX”