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

1. 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
   

2. 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
   

On the console, looking at the topmost right side of the dialog you should see a red button kinda like a buzzer. To stop the spring boot application properly you just ran, go ahead and hit this particular "red" button and your problem is solved. Hope this helps!

Another easy way of solving this error is right clicking in the console and click on Terminate/Disconnect All. Afterwards run the application it should work fine.