I\'ve generated classes with XMLBeans from an xsd file and packed them in a jar file. then I\'ve added that jar to the project classpath in eclipse and everything compiles and r
In your generated jar file make sure you have included the class files generated from your xmlbeans.
From the stacktrace :
Caused by: java.lang.ClassNotFoundException: schemaorg_apache_xmlbeans.system.s8
B21CFFFCFED0B2438C2585C61F113F7.TypeSystemHolder
it suggests that during compile time the required class files are in classpath but in your built jar these files are missing.
Check your jar file to see if these classes are present.
EDIT: As per question rephrased
For building jar with dependecies in Maven use jar-with-dependencies
option, example
Two very good reference :
http://www.sonatype.com/books/mvnref-book/reference/assemblies-sect-basics.html
http://thomassundberg.wordpress.com/2011/03/05/create-an-executable-jar-from-maven/
In the second one you don't need a main class if your jar is not an executable jar