For Java programs, Jenkins requires the use of build tools such as maven, ant, etc., with maven being more popular. Here we use maven to implement the deployment of Java applications. Prepare Java code in GitLab Deploy Tomcat and configure it apt-get -y install tomcat9 tomcat9-admin cp -r /usr/share/tomcat9-admin/* /var/lib/tomcat9/webapps/ Open /var/lib/tomcat9/conf/tomcat-users.xml and do the following configuration. Add the following three lines to create users and authorize them. manager-script for remote script execution privileges <role rolename="manager-gui"/> <role rolename="manager-script"/> <user username="tomcat" password="tomcat" roles="manager-gui,manager-script"/> Open /var/lib/tomcat9/webapps/manager/META-INF/context.