How get going with running and compiling Java programs in Debian real quick
In order to run java software you proboably need a jre package such as openjdk-6-jre. In order to compile java you need a jdk package such as openjdk-6-jdk. If you don't care which version of java is used, then default-jre and default-jdk are packages which exist on all platforms and give you something sensible.
sudo apt-get install openjdk-6-jdk
You reach java as /usr/bin/java . This file is really a link to /etc/alternatives/java , which in turn is a link to your java installation folder that's located in /usr/lib/jvm . For instance, java may link via /etc/alternatives/java to /usr/lib/jvm/java-6-openjdk/jre/bin/java .
If you have more detailed questions, you may be interested in seeing http://www.debian.org/doc/manuals/debian-java-faq/.
One particular reason that may lead your interest to read the tips above, is in case ant terminates for you with the error:
(path)/build.xml:49: Unable to find a javac compiler;
com.sun.tools.javac.Main is not on the classpath.
Perhaps JAVA_HOME does not point to the JDK
About pbuilder and Sun's Java SDK
I am build-depending on sun-javaX-jdk. However, I can't get an automatic build in a clean environment working, because sun-javaX-jdk does not install in a non-interactive environment, because it asks for license confirmation:
Unpacking sun-java6-jdk (from .../sun-java6-jdk_6-06-1_amd64.deb) ... sun-dlj-v1-1 license could not be presented try 'dpkg-reconfigure debconf' to select a frontend other than noninteractive
There are two possible answers:
Patch one and for all your pbuilder environment
$ sudo pbuilder login --save-after-login # echo "sun-java5-jdk shared/accepted-sun-dlj-v1-1 boolean true" | debconf-set-selections # echo "sun-java6-jdk shared/accepted-sun-dlj-v1-1 boolean true" | debconf-set-selections # exit
Add a hook to patch it on the fly
In http://lists.debian.org/debian-java/2008/05/msg00024.html Manuel Prinz says:
- I use a way to do that "on the fly" because I think it's easier to manage if you have several debconf settings to manage. Just add to your .pbuilderrc:
HOOKDIR=$HOME/debian/pbuilder/hooksThe create a file called i.e. "D50sun-java-licenses" in $HOOKDIR with the following content (it basically has to start with "D" and a two digit number for ordering):
#!/bin/sh debconf-set-selections <<EOF sun-java5-jdk shared/accepted-sun-dlj-v1-1 boolean true sun-java6-jdk shared/accepted-sun-dlj-v1-1 boolean true EOFThis accepts the licenses before packages are installed. I prefer this because I can deactivate certain settings easily (by commenting out sections or renaming hook files) and do not have to keep a full chroot for every possible debconf setting. Also, I tend to forget which exactly setting I did in which chroot.
As mentioned in man pbuilder, you need to make the hook script (D50sun-java-licenses) executable before pbuilder will load it.