Updated by Marco Massenzio 2020-12-29

File update-jdk Modified

     /usr/lib/jvm folder (used by the update-java-alternatives command).

     See also: http://manpages.ubuntu.com/manpages/precise/man8/update-java-alternatives.8.html

+    Author: Marco Massenzio (https://codetrips.com) (c) 2020.  All rights reserved.

+    Released under the Apache 2.0 License (https://www.apache.org/licenses/LICENSE-2.0.html)

Created by Marco Massenzio 2020-12-29

View revision

File update-jdk Added

+#!/bin/bash

+#

+# Sets up a new Java JDK

+# Loosely based on https://askubuntu.com/questions/1079239/can-not-install-jdk11-using-update-alternatives-install

+set +eu

+function usage {

+    echo "Usage: $(basename $0) [-h] JDK [PRIORITY [ALIAS]]

+    Configures a new Java JDK as downloaded from https://jdk.java.net and

+    untarred into /usr/lib/jvm.

+    -h          prints this help and exits

+    JDK         the OpenJDK directory in /usr/lib/jvm/\$JDK

+    PRIORITY    an optional priority value (numeric), default: 1010

+    ALIAS       an optional JDK alias

+    Allows supporting multiple JDKs on the same Ubuntu installation, and the use

+    of update-java-alternatives to switch between them.

+    This script expects the OpenJDK root folder to be in /usr/lib/jvm and its name

+    to match the first argument (JDK); it will also create .\$JDK.jinfo file in the

+    /usr/lib/jvm folder (used by the update-java-alternatives command).

+    See also: http://manpages.ubuntu.com/manpages/precise/man8/update-java-alternatives.8.html

+"

+}

+if [[ ${1:-} == "-h" ]]; then

+    usage

+    exit 0

+fi

+jdk=${1:-}

+priority=${2:-1010}

+alias=${3:-${jdk}}

+jinfo="/usr/lib/jvm/.${jdk}.jinfo"

+if [[ -z ${jdk} || ! -d /usr/lib/jvm/${jdk} ]]; then

+    usage

+    exit 1

+fi

+cat <<EOF >${jinfo}

+name=${jdk}

+alias=${alias}

+priority=${priority}

+section=main

+EOF

+for c in $(ls /usr/lib/jvm/${jdk}/bin); do

+    bin=/usr/lib/jvm/${jdk}/bin/$c

+    update-alternatives --install /usr/bin/$c $c ${bin} ${priority}

+    echo "jdkhl $c ${bin}" >>${jinfo}

+done

+update-java-alternatives -s ${jdk}