Solution
You can use the troubleshooting tips below.
Troubleshooting Tip #1
Exit Eclipse
Open a web browser and visit, http://localhost:8080
If you see a "Tomcat" web page then that means Tomcat is running as a Windows service. To stop Tomcat running as a Windows services, open your Windows Control Panel. Find the service "Apache Tomcat" and stop it.
If you don't see a "Tomcat" web page, then stop the appropriate process displayed.
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Troubleshooting Tip #2 - GUI Option
Steps to free port which is already used to run Tomcat server in Eclipse
On MS Windows, select Start > All Programs > Accessories > System Tools >Resource Monitor
Expand the Network Tab
Move to the section for Listening Ports
Look in the Port column and scroll to find entry for port 8080
Select the given process and delete/kill the process
Return back to Eclipse and start the Tomcat Server, it should start up now.
Troubleshooting Tip #3 - Command-Line Option
Steps to free port which is already used to run Tomcat server in Eclipse
For example , suppose 8080 port is used , we need to make free 8080 to run tomcat
Step 1: (open the CMD command)
C:\Users\username>netstat -o -n -a | findstr 0.0:8080
TCP 0.0.0.0:3000 0.0.0.0:0 LISTENING 3116
Now , we can see that LISTENING port is 3116 for 8080 ,
We need to kill 3116 now
Step 2:
C:\Users\username>taskkill /F /PID 3116
Step 3: Return back to Eclipse and start the Tomcat Server, it should start up now.
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Mac/Linux SOLUTION
Step 0: Exit Eclipse
Step 1: Open a terminal window
Step 2: Enter the following command to find the process id
lsof -i :8080
This will give output of the application that is running on port 8080
Step 3: Enter the following command to kill the process
kill $(lsof -t -i :8080)
Step 4: Return back to Eclipse and start the Tomcat Server, it should start up now.