sun java Linux install using update-alternatives

###################
# oracle jdk Final solution (to run, just copy and paste everything here and below into a shell)
###################

#-------------------------------
# Settings (optional; automatic)
#-------------------------------

# Path to jdk, eg. /opt/jdk1.7.0_17/
# Optional. If blank, it's automatically found (latest in /opt/jdk*).
export XSUNJAVA=

#======================
# Optional, for openjdk

# opensuse 13.1:
export XOPENJDK=/usr/lib64/jvm/java-1.7.0-openjdk/

# ubuntu 12:
#export XOPENJDK=/usr/lib/jvm/java-6-openjdk-amd64/
#======================

#-----------
# automatic config
#-----------

# number to identy this alternative (for having more than 1 version)
export n=1

if [ -z "$XSUNJAVA" ]; then
    XSUNJAVA=$(ls -1d /opt/jdk* | sort | tail -n1)
fi

# Depending on if you have a 64 bit or 32 bit machine
# Only relevant for the browser plugin
if [ -e /usr/lib64 ]; then
    libDir=/usr/lib64
else
    libDir=/usr/lib
fi

#-----------
# Main
#-----------

update-alternatives --remove-all java
update-alternatives --remove-all javac
update-alternatives --remove-all keytool
update-alternatives --remove-all javaplugin
update-alternatives --remove-all javaws
update-alternatives --remove-all java_home
update-alternatives --remove-all jdk_home

# Directories (for use in JAVA_HOME environment variable)
update-alternatives --install /opt/java java_home ${XSUNJAVA} $n
update-alternatives --install /opt/jdk  jdk_home  ${XSUNJAVA} $n
if [ ! -e "${XOPENJDK}" ]; then
    echo "SKIPPING OpenJDK"
elif [ -n "${XOPENJDK}" ]; then
    update-alternatives --install /opt/java java_home ${XOPENJDK} $((n+1))
    update-alternatives --install /opt/jdk  jdk_home  ${XOPENJDK} $((n+1))
fi
update-alternatives --set java_home ${XSUNJAVA}
update-alternatives --set jdk_home ${XSUNJAVA}

# Commands using alternative directories
update-alternatives --install /usr/bin/java java /etc/alternatives/jdk_home/bin/java 1
update-alternatives --install /usr/bin/javac javac /etc/alternatives/jdk_home/bin/javac 1
update-alternatives --install /usr/bin/keytool keytool /etc/alternatives/jdk_home/bin/keytool 1
update-alternatives --install /usr/bin/javaws javaws /etc/alternatives/jdk_home/bin/javaws 1
update-alternatives --set java /etc/alternatives/jdk_home/bin/java
update-alternatives --set javac /etc/alternatives/jdk_home/bin/javac
update-alternatives --set keytool /etc/alternatives/jdk_home/bin/keytool
update-alternatives --set javaws /etc/alternatives/jdk_home/bin/javaws

if [ -d "${libDir}/browser-plugins/" ]; then
# For the browser plugin
    update-alternatives --install ${libDir}/browser-plugins/javaplugin.so javaplugin /etc/alternatives/java_home/jre/lib/amd64/libnpjp2.so 1
    update-alternatives --install ${libDir}/browser-plugins/javaplugin.so javaplugin ${libDir}/IcedTeaPlugin.so 2
    update-alternatives --set javaplugin /etc/alternatives/java_home/jre/lib/amd64/libnpjp2.so
fi

if [ -n "${XOPENJDK}" ]; then
    # add the normal name for javaws to openJDK
    ln -s /usr/bin/itweb-javaws "${XOPENJDK}"/bin/javaws
    ln -s /usr/bin/itweb-javaws "${XOPENJDK}"/jre/bin/javaws
    ln -s /etc/alternatives/jdk_home /usr/lib64/jvm/jre
fi

# add JAVA_HOME to current shell
export JAVA_HOME=/etc/alternatives/java_home/

# add JAVA_HOME to your environment
if ! egrep -c "^JAVA_HOME=/etc/alternatives/java_home/$" /etc/profile >/dev/null 2>&1; then
    # ^ if the exact line we want is not in /etc/profile
    echo "Updating /etc/profile"
    # remove any JAVA_HOMEs in there
    egrep -v "^JAVA_HOME" /etc/profile > /etc/profile.javatmp
    # add JAVA_HOME
    echo "JAVA_HOME=$JAVA_HOME" >> /etc/profile.javatmp
    mv /etc/profile.javatmp /etc/profile
    echo "Done updating /etc/profile"
fi

java -version


experimental removal
=======

update-alternatives --config jdk_home
update-alternatives --config java_home
update-alternatives --config javaplugin





###################
undo
###################

update-alternatives --remove-all java
update-alternatives --remove-all javac
update-alternatives --remove-all keytool
update-alternatives --remove-all javaplugin
update-alternatives --remove-all javaws
update-alternatives --remove-all jar
update-alternatives --remove-all java_home
update-alternatives --remove-all javah
update-alternatives --remove-all jdk_home

jre=/usr/lib64/jvm/java-openjdk/jre
jdk=/usr/lib64/jvm/java-openjdk
plugin=/usr/lib64/java-1_8_0-openjdk-plugin/lib/IcedTeaPlugin.so
libDir=/usr/lib64

update-alternatives --install /usr/bin/java java "$jre"/bin/java 1
update-alternatives --install /usr/bin/javac javac "$jdk"/bin/javac 1
update-alternatives --install /usr/bin/keytool keytool "$jre"/bin/keytool 1

update-alternatives --install ${libDir}/browser-plugins/javaplugin.so javaplugin "$plugin" 1