update-oracle-java-alternative.sh

update-oracle-java-alternative.sh

#!/bin/bash

set -e

script_name=$(basename "$0")

print_usage()
{
    cat <<EOF
Usage: ${script_name} install ORACLE_JAVA_INSTALL_DIR [PRIORITY]
       ${script_name} remove  ORACLE_JAVA_INSTALL_DIR

This script manages an Oracle JRE installation using the standard
'alternatives' tool to set the Oracle JRE (java) and browser plugin
(libnpjp2.so) as the system default. This allows OpenJDK to be installed
concurrently in order to satisfy the package dependency of other yum-installed
applications (e.g. LibreOffice).

This script has been tested on CentOS 7 and:
 - Oracle Java 1.8.0_11 (installed via jre-8u11-linux-x64.rpm)
 - Oracle Java 1.8.0_25 (installed via jre-8u25-linux-x64.rpm)
EOF
}

install_alternative()
{
    JAVA_HOME=$(readlink -e $1)
    PRIORITY=${2:-1000000}
    
    sudo update-alternatives \
      --install /usr/bin/java          java        ${JAVA_HOME}/bin/java        ${PRIORITY} \
      --slave /usr/bin/keytool         keytool     ${JAVA_HOME}/bin/keytool     \
      --slave /usr/bin/orbd            orbd        ${JAVA_HOME}/bin/orbd        \
      --slave /usr/bin/pack200         pack200     ${JAVA_HOME}/bin/pack200     \
      --slave /usr/bin/rmid            rmid        ${JAVA_HOME}/bin/rmid        \
      --slave /usr/bin/rmiregistry     rmiregistry ${JAVA_HOME}/bin/rmiregistry \
      --slave /usr/bin/servertool      servertool  ${JAVA_HOME}/bin/servertool  \
      --slave /usr/bin/tnameserv       tnameserv   ${JAVA_HOME}/bin/tnameserv   \
      --slave /usr/bin/unpack200       unpack200   ${JAVA_HOME}/bin/unpack200   \
      --slave /usr/lib/jvm/jre         jre         ${JAVA_HOME}                 \
      --slave /usr/lib/jvm-exports/jre jre_exports ${JAVA_HOME}/lib             
    sudo update-alternatives --auto java
    
    if [[ ${JAVA_HOME} =~ "1.7.0" ]]; then
        sudo update-alternatives \
            --install /usr/lib/jvm/jre-1.7.0       jre_1.7.0         ${JAVA_HOME}     ${PRIORITY} \
            --slave /usr/lib/jvm-exports/jre-1.7.0 jre_1.7.0_exports ${JAVA_HOME}/lib
        sudo update-alternatives --auto jre_1.7.0
    fi
    
    sudo update-alternatives \
        --install /usr/lib64/mozilla/plugins/libjavaplugin.so libjavaplugin.so.x86_64 ${JAVA_HOME}/lib/amd64/libnpjp2.so ${PRIORITY} \
        --slave /usr/bin/javaws                               javaws                  ${JAVA_HOME}/bin/javaws
    sudo update-alternatives --auto libjavaplugin.so.x86_64
}

remove_alternative()
{
    JAVA_HOME=$(readlink -m $1)
    sudo update-alternatives --remove java ${JAVA_HOME}/bin/java 2>/dev/null || \
        echo "${JAVA_HOME}/bin/java already removed"
    if [[ ${JAVA_HOME} =~ "1.7.0" ]]; then
        sudo update-alternatives --remove jre_1.7.0 ${JAVA_HOME} 2>/dev/null || \
            echo "${JAVA_HOME} already removed"
    fi
    sudo update-alternatives --remove libjavaplugin.so.x86_64 ${JAVA_HOME}/lib/amd64/libnpjp2.so 2>/dev/null || \
        echo "${JAVA_HOME}/lib/amd64/libnpjp2.so already removed"
}

case "$1" in
    install)
        install_alternative $2 $3
        ;;
    remove)
        remove_alternative $2
        ;;
    *)
        print_usage 1>&2
        exit 1
        ;;
esac