Error message:
Unable to start web server; nested exception is org.springframework.boot.web.server.WebServerException: Unable to start embedded Tomcat
Cause Analysis:
1. Check whether your pom has added wrong files and conflicts
This is an error reported by my own project.
2. Or if your own files are not added to the compiled file, just clean maven and restart.
3. Check whether the annotation @SpringBootApplication is added to the startup class
