install a dummy java so debian or ubuntu apt will be happy with an install oracle jdk - in this case for octave but should work for others too

dummy_java.sh

#!/bin/bash
# deps:
#  - have oracle jdk >= 7 build with java-package
#    see https://wiki.debian.org/JavaPackage if you don't know how
#  - apt-get install equivs
#
#  Debian actually kind of suggests it but the doc ist kind of old:
#    https://www.debian.org/doc/manuals/debian-java-faq/ch13.html
#  
#  inspired by RJ <[email protected]>
#    https://gist.github.com/RJ/94c8b37908c331093fcc

for NAME in default-jre default-jre-headless openjdk-7-jre-headless; do
echo "Section: interpreters
Priority: optional
Standards-Version: 3.6.2

Package: $NAME
Version: 1:99
Maintainer: ben <[email protected]>
Provides: $NAME
Description: fake $NAME package
 to pretend $NAME is installed for apts sake (we use oracle pkgs)" > $NAME
equivs-build $NAME
echo -e "\nRUN: dpkg -i ./$NAME*.deb\n"
done
echo "-----------"
echo "now run the printed dpkg -i commands and install octave"