Install Java in Ubuntu 20.04
First we will make sure our system is up-to-date
sudo su apt update
We need to verify if java is installed
If we do not have Java installed, we will receive the output shown above. We can install java with the below command.
#for java 8 apt install openjdk-8-jdk -y #for java 11 sudo apt install openjdk-11-jdk -y #check installed java version java -version
Install Tomcat 9 on Ubuntu 20.04
First, we need to create a group and a user for Tomcat.
groupadd tomcat useradd -s /bin/false -g tomcat -d /opt/tomcat tomcat
Download tomcat tar file
cd /tmp/ sudo curl -O https://dlcdn.apache.org/tomcat/tomcat-9/v9.0.64/bin/apache-tomcat-9.0.64.tar.gz
Create a directory for tomcat and unpack the tar file in it
mkdir /opt/tomcat tar -xvf apache-tomcat-9*tar.gz -C /opt/tomcat --strip-components=1
Provide permissions to the tomcat directory
cd /opt/tomcat sudo chgrp -R tomcat /opt/tomcat sudo chmod -R g+r conf sudo chmod g+x conf sudo chown -R tomcat webapps/ work/ temp/ logs/
Open a file called tomcat.service in the /etc/systemd/system directory by executing the below command
sudo nano /etc/systemd/system/tomcat.service
Paste the below content in the file:
[Unit] Description=Apache Tomcat Web Application Container After=network.target [Service] Type=forking Environment=JAVA_HOME=/usr/lib/jvm/java-1.8.0-openjdk-amd64/jre Environment=CATALINA_PID=/opt/tomcat/temp/tomcat.pid Environment=CATALINA_HOME=/opt/tomcat Environment=CATALINA_BASE=/opt/tomcat Environment='CATALINA_OPTS=-Xms512M -Xmx1024M -server -XX:+UseParallelGC' Environment='JAVA_OPTS=-Djava.awt.headless=true -Djava.security.egd=file:/dev/./urandom' ExecStart=/opt/tomcat/bin/startup.sh ExecStop=/opt/tomcat/bin/shutdown.sh User=tomcat Group=tomcat UMask=0007 RestartSec=10 Restart=always [Install] WantedBy=multi-user.target
Save and exit.
Execute the below command to reload the daemons
Start the Tomcat service by executing the below command
systemctl start tomcat
Check tomcat status with the below command
# to check status systemctl status tomcat # to stop tomcat systemctl stop tomcat # to restart tomcat systemctl restart tomcat
Now you can access the tomcat service on your browser. If you have installed tomcat in your local system, then enter the URL: http://localhost:8080. If you have installed it on a cloud instance, then enter the URL: http://<public_ip>:8080
Done. We have successfully installed Tomcat 9 on Ubuntu 20.04.
Change Tomcat port
If you have any other service already running on port number 8080, then you with either have to stop that service and then start tomcat to access it on the browser. Or else, you can change the tomcat port so that there is no conflict between the port and services. Follow the below steps to change the tomcat port,
- Edit the server.xml file in tomcat directory to change the port number. Execute the below command to edit the service.xml file
sudo nano /opt/tomcat/conf/server.xml
Move down and find the below lines in configuration file
<Connector port="8080" protocol="HTTP/1.1" connectionTimeout="20000" redirectPort="8443" />
Change the port number here from 8080 to 8090 or any other port that is free in your system
<Connector port="8090" protocol="HTTP/1.1" connectionTimeout="20000" redirectPort="8443" />
Save and exit by pressing Ctrl X -> Y -> Enter keys
Now restart tomcat with the below command for the changes to take effect
sudo systemctl restart tomcat
Now you can access the Tomcat webpage with the new port number.