In this post I will show you the step-by-step instructions to deploy a WAR file in Tomcat 11:

1. Build Your WAR File

A WAR file (.war) is a packaged web application. To build it:

• If you’re using Maven, run the following command in your project directory:

  mvn clean package
  

  This generates a WAR file under the target/ folder.

• If you’re using other tools (e.g., Gradle, IDE), export the WAR file using the packaging/export option.

2. Install and Configure Tomcat 11

• Download Tomcat 11 from the official website: Apache Tomcat Downloads
• Extract the downloaded ZIP/TAR file to a desired directory.
• Navigate to the conf/ directory and optionally configure the file server.xml to customize ports, define your hostname, or adjust server parameters (optional for default usage).

3. Start Tomcat

• Navigate to the bin/ directory.

• Run the startup script as per your operating system:

  • On Windows:

    startup.bat
    

  • On Linux/Mac:

    ./startup.sh
    

• By default, Tomcat runs on port 8080. Check if it is running by accessing:

  http://localhost:8080/
  

  If Tomcat is running, its welcome page should appear.

4. Deploy Your WAR File

You have two primary ways to deploy the WAR file:

a) Manual Deployment

1. Copy the WAR file to Tomcat’s webapps/ directory:
   • Navigate to the webapps/ directory inside your Tomcat installation path.
   • Copy your WAR file (e.g., HelloWorld.war) into this folder.

     cp /path/to/HelloWorld.war /path/to/tomcat/webapps/
     

2. Restart Tomcat:
   • Stop and restart Tomcat for new deployments to take effect, using:

     shutdown.bat/startup.bat (Windows)
     ./shutdown.sh && ./startup.sh (Linux/Mac)
     

3. Access Your Application:
   • By default, the application will be available at:

     http://localhost:8080/<war-file-name>/
     

   • For example:

     http://localhost:8080/HelloWorld/
     

b) Upload via Tomcat Manager (Web UI)

1. Go to the Tomcat Manager application at:
2. Log in with your username and password:
   • Default username: admin
   • Default password: admin (or use the one you set in tomcat-users.xml file under conf/).
     To set new credentials, update the conf/tomcat-users.xml file by adding:

     <role rolename="manager-gui"/>
     <user username="admin" password="admin" roles="manager-gui"/>
     

3. Scroll to the Deploy section:
   • Under “WAR file to deploy,” choose the WAR file from your system.
   • Click the Deploy button.
4. Access Your Application:
   • The application URL will be:

     http://localhost:8080/<war-file-name>/
     

5. Check Logs for Errors (if any)

If the application is not working, check Tomcat logs:

• Log files are located in the logs/ directory of your Tomcat installation.
• The most relevant logs include:
  • catalina.<date>.log – Main log file for Tomcat.
  • localhost.<date>.log – Logs specific to deployed applications.

6. Stop Tomcat (if needed)

If you wish to shut down Tomcat:

• Navigate to the bin/ directory.
• Use the shutdown script:
  • On Windows:

    shutdown.bat
    

  • On Linux/Mac:

    ./shutdown.sh
    

Summary of Key Directories in Tomcat

Directory	Purpose
bin/	Contains scripts to start and stop Tomcat.
conf/	Stores configuration files like server.xml.
webapps/	Holds deployed WAR files.
logs/	Contains log files for troubleshooting.