Retrieve the latest version of Asterisk-Java from SVN:
svn co http://svn.reucon.net/repos/asterisk-java/trunk asterisk-java
Then change to the created asterisk-java directory and use Maven2 to build the project
cd asterisk-java mvn install
This will create the asterisk-java-$VERSION.jar in the target subdirectory as well as in your local maven repository.