sudo wget -O /etc/yum.repos.d/jenkins.repo http://pkg.jenkins-ci.org/redhat/jenkins.repo
sudo rpm --import https://jenkins-ci.org/redhat/jenkins-ci.org.key
sudo yum install jenkins

sudo yum install java

sudo service jenkins start/stop/restart
sudo chkconfig jenkins on

firewall-cmd --zone=public --add-port=8080/tcp --permanent
firewall-cmd --zone=public --add-service=http --permanent
firewall-cmd --reload

firewall-cmd --list-all

java -version
java version "1.5.0"
gij (GNU libgcj) version 4.4.6 20110731 (Red Hat 4.4.6-3)

yum remove java

yum install java-1.7.0-openjdk

java -version
java version "1.7.0_79"
OpenJDK Runtime Environment (rhel-2.5.5.1.el6_6-x86_64 u79-b14)
OpenJDK 64-Bit Server VM (build 24.79-b02, mixed mode)

JENKINS_PORT="8080"

sudo service jenkins start

vi /etc/init.d/jenkins

[root@iZ94xvn71eeZ ~]# vim /etc/init.d/jenkins 


# Set up environment accordingly to the configuration settings
[ -n "$JENKINS_HOME" ] || { echo "JENKINS_HOME not configured in $JENKINS_CONFIG";
  if [ "$1" = "stop" ]; then exit 0;
  else exit 6; fi; }
[ -d "$JENKINS_HOME" ] || { echo "JENKINS_HOME directory does not exist: $JENKINS_HOME";
  if [ "$1" = "stop" ]; then exit 0;
  else exit 1; fi; }

# Search usable Java as /usr/bin/java might not point to minimal version required by Jenkins.
# see http://www.nabble.com/guinea-pigs-wanted-----Hudson-RPM-for-RedHat-Linux-td25673707.html
candidates="
/etc/alternatives/java
/usr/lib/jvm/java-1.8.0/bin/java
/usr/lib/jvm/jre-1.8.0/bin/java
/usr/lib/jvm/java-1.7.0/bin/java
/usr/lib/jvm/jre-1.7.0/bin/java
/usr/bin/java
/usr/java/jdk1.7.0_80/bin/java
"