Bug#820857: java-package: Generated JDK package should have higher priority than existing openjdk packages

[Jan Henke]

Package: java-package
Version: 0.60
Severity: normal

Given the following situation. I have openjdk-8-jdk installed from the
archive. For work I need the Oracle JDK, so I download the *.tar.gz and
create a debian package from it with java-package. I install the created
package, so I have both the openjdk-8-jdk from the archive and the
Oracle JDK installed.

Now I run java -version on the command line.

Expected result: The java binary from the Oracle JDK is used by default.
Actual result: The openjdk java binary is still used.
(It is the same for all binaries, which are provided by both Java
implementations).

It turns out, the package generated by java-package has a much lower
priority(380) for update-alternatives then then openjdk(~1000) package.

Please change the java-package tool, so that the generated packages have
the highest priority of all Java implemenations and are used by default.

Rationale: If I create a Debian package with make-jpkg and install it,
it is a deliberate act, that I want that Java implemantation on my
machine. It should therefore be used by default. Not using this
implementation after installing it is unexpected and against user expectation.

-- System Information:
Debian Release: stretch/sid
  APT prefers xenial-updates
  APT policy: (500, 'xenial-updates'), (500, 'xenial-security'), (500, 'xenial'), (100, 'xenial-backports')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 4.4.0-18-generic (SMP w/4 CPU cores)
Locale: LANG=de_DE.UTF-8, LC_CTYPE=de_DE.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)

Versions of packages java-package depends on:
ii  build-essential  12.1ubuntu2
ii  debhelper        9.20160115ubuntu3
ii  dpkg-dev         1.18.4ubuntu1
ii  fakeroot         1.20.2-1ubuntu1
ii  libasound2       1.1.0-0ubuntu1
ii  libfontconfig1   2.11.94-0ubuntu1
ii  libgl1-mesa-glx  11.2.0-1ubuntu1
ii  libgtk2.0-0      2.24.30-1ubuntu1
ii  libx11-6         2:1.6.3-1ubuntu2
ii  libxslt1.1       1.1.28-2.1
ii  libxtst6         2:1.2.2-1
ii  libxxf86vm1      1:1.1.4-1
ii  unzip            6.0-20ubuntu1

java-package recommends no packages.

Versions of packages java-package suggests:
pn  openjdk-7-jre  <none>

-- no debconf information