http://www.oracle.com/technetwork/java/javase/downloads/jdk6u37-downloads-1859587.html から
テキトーにDLしてscpで送り込むとか
chmod a+x jdk-6u37-linux-x64-rpm.bin
./jdk-6u37-linux-x64-rpm.bin
#必要に応じてパス追加 /etc/profile 末尾とか
export JAVA_HOME=/usr/java/default
export PATH=$PATH:$JAVA_HOME/bin
export CLASSPATH=.:$JAVA_HOME/jre/lib:$JAVA_HOME/lib:$JAVA_HOME/lib/tools.jar
# http://pkg.jenkins-ci.org/redhat/
wget -O /etc/yum.repos.d/jenkins.repo http://pkg.jenkins-ci.org/redhat/jenkins.repo
rpm --import http://pkg.jenkins-ci.org/redhat/jenkins-ci.org.key
yum install jenkins -y
service jenkins start