Originally published October 26, 2016 @ 12:46 am

Below is shorthand for installing alternative versions of Java on your RHEL/CentOS system. This may come in useful for the purposes of testing.

# Set version, update, and filename

v="jdk1.8.0_101"
r="8u101-b13"
f="jdk-8u101-linux-x64.tar.gz"

cd /opt
wget --no-cookies --no-check-certificate --header "Cookie: gpw_e24=http%3A%2F%2Fwww.oracle.com%2F; oraclelicense=accept-securebackup-cookie" \
"http://download.oracle.com/otn-pub/java/jdk/${r}/${f}"
tar xzf ${f} && /bin/rm -f ${f}
cd /opt/${v}
alternatives --install /usr/bin/java java /opt/${v}/bin/java 2
alternatives --install /usr/bin/jar jar /opt/${v}/bin/jar 2
alternatives --install /usr/bin/javac javac /opt/${v}/bin/javac 2
alternatives --set jar /opt/${v}/bin/jar
alternatives --set javac /opt/${v}/bin/javac
export JAVA_HOME=/opt/${v}
export JRE_HOME=/opt/${v}/jre
export PATH=$PATH:/opt/${v}/bin:/opt/${v}/jre/bin
cat >> /etc/environment << EOF
JAVA_HOME=/opt/${v}
JRE_HOME=/opt/${v}/jre
PATH=$PATH:/opt/${v}/bin:/opt/${v}/jre/bin
EOF

Interactive step – select default Java version and verify
alternatives --config java
java -version