Spring Boot application in eclipse, the Tomcat connector configured to listen on port XXXX failed to start

Find the process ID (PID) for the port (e.g.: 8080)

On Windows:

netstat -ao | find "8080"

Other Platforms other than windows :

lsof -i:8080

Kill the process ID you found (e.g.: 20712)

On Windows:

Taskkill /PID  20712 /F

Other Platforms other than windows :

kill -9 20712   or kill 20712