question: protected void initFromDir ( String prefix , File dir ) { File [ ] files ; files = dir . listFiles ( new ClassFileFilter ( ) ) ; for ( File file : files ) { if ( prefix == null ) { add ( file . getName ( ) ) ; } else { add ( prefix + "." + file . getName ( ) ) ; } } files = dir . listFiles ( new DirectoryFilter ( ) ) ; for ( File file : files ) { if ( prefix == null ) { initFromDir ( file . getName ( ) , file ) ; } else { initFromDir ( prefix + "." + file . getName ( ) , file ) ; } } }
target:  Fills the class cache with classes in the specified directory.