the current code of OpenJPA can be enhanced by:
1.) replacing Numbers.valueOf( int ) and Numbers.valueOf( long ) by their conunterparts in Integer and Long, as well as replacing new Integer/Byte/Short/Long/Character by their factory-methods
2.) replace StringBuffer by StringBuilder, replace .append( "x" ) by .append( 'x' ) where possible
3.) use more generics ( in Iterators, for example)
attached is a patch which contains 1.) for the below openjpa-jdbc/..