8080 port already taken issue when trying to redeploy project from Spring Tool Suite IDE

It sometimes happen even when we stop running processes in IDE with help of Red button , we continue to get same error.

It was resolved with following steps,

1. Check what processes are running at available ports

   netstat -ao |find /i "listening"

   We get following

   TCP 0.0.0.0:7981 machinename:0 LISTENING 2428
TCP 0.0.0.0:7982 machinename:0 LISTENING 2428
TCP 0.0.0.0:8080 machinename:0 LISTENING 12704
TCP 0.0.0.0:8500 machinename:0 LISTENING 2428

   i.e. Port Numbers and what Process Id they are listening to

2. Stop process running at your port number(In this case it is 8080 & Process Id is 12704)

   Taskkill /F /IM 12704 (Note: Mention correct Process Id)

For more information follow these links Link1 and Link2.

My Issue was resolved with this, Hope this helps !

For Mac users(OS X El Capitan):

You need to kill the port that localhost:8080 is running on.
To do this, you need to do two commands in the terminal :N

sudo lsof -i tcp:8080

kill -15 PID 

NB! PID IS A NUMBER PROVIDED BY THE FIRST COMMAND.

The first command gives you the PID for the localhost:8080.
Replace the PID in the second command with the PID that the first command gives you to kill the process running on localhost:8080.

The reason is one servlet container is already running on port 8080 and you are trying to run another one on port 8080.

• 1. Check what processes are running at available ports.

     • For Windows :

     • netstat -ao |find /i "listening"
       

     OR

     • netstat -ano | find "8080" (Note: 8080 is port fail to start)
       

• 2. Now try to reLaunch or stop your application.

     • To relaunch: you can press this button

  

  • To stop in windows:

  Taskkill /F /IM 6592
  Note: Mention correct Process Id

  

  right click on the console and select terminate/disconnect all

  • Go to Task Manager and end Java(tm) platform se binary

  

  What is java(tm) platform se binary(Search in google

Another option is :

Go to application.properties file set server.port=0. This will cause Spring Boot to use a random free port every time it starts.

Create application.properties file under src/main/resources folder and write content as

server.port=8084

Its runs fine.
But every time before run need to stop application first by click on red button upper on the IDE

or try

RightClick on console>click terminate/Disconnect All