Maven3, Javac & Co. On Debian

http://blog.giuseppeurso.net/wp-content/uploads/2013/05/apache-maven-project-2.jpg

Maven3 &the right JDK
I was trying to build Maven3, to build other stuff (hippo cms) and suddenly my system said:
BUILD FAILED
/usr/src/apache-maven-3.0.5/build.xml:223: Unable to find a javac compiler;
com.sun.tools.javac.Main is not on the classpath.
Perhaps JAVA_HOME does not point to...
Maven3, Javac & Co. On Debian