To run Java applications on the web there is a one web server which provide web server as well as servlet container.Apache server Foundation released open source project Tomcat .
Main feature in this Tomcat version 8 and release are :
- JSE 2.3
- It supports Java Servlet 3.1
- Java WebSocket 1.0
- Java Unified Expression Language ( EL ) 3.0
Prerequisites to Tomcat 8 and its releases :
Apache Tomcat 8 prerequisites is Java 7 or higher version of java .
Here we are using root user to install and configure apache tomcat server on CentOs server.
Install Java and Check Version :
Java 7 or higher version is required to install tomcat server , Here we have already explain in our other post how to do installation of java on CentOs and Red Hat Server version .
Now I am giving output of my server java version .
# java -version java version "1.8.0_51" Java(TM) SE Runtime Environment (build 1.8.0_51-b16) Java HotSpot(TM) 64-Bit Server VM (build 25.51-b03, mixed mode)
Steps for setup Tomcat :
After set up of Java version, now we can start work on apache tomcat 8 using below command , I am working as a root user in my server vm. You can download apache tomcat version form apache tomcat official page or here you can find official page url of tomcat 8 .
Follow below command in setup and configuring.
# cd /tmp # wget http://mirror.metrocast.net/apache/tomcat/tomcat-8/v8.0.26/bin/apache-tomcat-8.0.26.tar.gz # tar xzf apache-tomcat-8.0.26.tar.gz # mv apache-tomcat-8.0.26 /opt
Configuring CATALINA_HOME Environment Variable :
Put the below command to set up environment variable .
# echo "export CATALINA_HOME=\"/opt/apache-tomcat-8.0.26\"" >> ~/.bashrc # source ~/.bashrc
Starting Apache Tomcat Server :
It is very simple to start the service of apache tomcat . Tomcat server works on default 8080 . We can change the default port on application . First we are going to start the server on port 8080 , after that we will change the port from 8080 to another free port.
# cd /opt/apache-tomcat-8.0.26 # ./bin/startup.sh
Output Status of Apache Tomcat:
# ./bin/startup.sh Using CATALINA_BASE: /opt/apache-tomcat-8.0.26 Using CATALINA_HOME: /opt/apache-tomcat-8.0.26 Using CATALINA_TMPDIR: /opt/apache-tomcat-8.0.26/temp Using JRE_HOME: /usr Using CLASSPATH: /opt/apache-tomcat-8.0.26/bin/bootstrap.jar:/opt/apache-tomcat-8.0.26/bin/tomcat-juli.jar Tomcat started.
Apache Tomcat access URL after installation :
After installation of apache tomcat we can access url or IP of server though port 8080 in web browser like below I have tested apache tomcat installation .
Managing Users & Roles :
If you want to manage users and roles of admin,managers for Apache Tomcat , you should know Catalina base and config files used by tomcat apache.We have install Tomcat in /opt folder and set Catalina path in environment variable /opt/apache-tomcat-8.0.26/ , Now here conf/tomcat-users.xml file for secure and manage the admin and manager roles.
You need to search “tomcat-users” script tag in file and in between script tag , edit and put the below content for manager role .
<role rolename="manager-gui"/> <user username="MANAGER_USERNAME" password="MANAGER_PASSWROD" roles="manager-gui"/>
and for both admin and manager previlages , edit and put the below lines in tomcat-users in between script tag .
<role rolename="admin-gui" /> <user username="ADMIN_USERNAME" password="ADMIN_PASSWORD" roles="manager-gui,admin-gui" />
# ./bin/shutdown.sh # ./bin/startup.sh
Now open the URL with your domain name or IP like below .
http://www.example.com:8080/manager/html OR http://www.example.com:8080/manager
Default port change to other :
(1) Locate conf/server.xml in tomcat installation folder ( /opt/apache-tomcat-8.0.2) .
(2) Search “Connector port” text in server.xml . Change the Connector port=”8080″ port to any other port number. Here i have change to 8081 .
<Connector port="8081" protocol="HTTP/1.1" connectionTimeout="20000" redirectPort="8443" />
(3) save and exit from the server.xml file and restart Tomcat Apache server .