private void compileJavaClasses(ClassLoader classLoader, List<String> javaFiles, String rootFolder) {
if ( !javaFiles.isEmpty() ) {
String[] sourceFiles = javaFiles.toArray( new String[javaFiles.size()] );
EclipseJavaCompiler compiler = createCompiler( rootFolder );
CompilationResult res = compiler.compile( sourceFiles,
srcMfs,
trgMfs,
classLoader );
for ( CompilationProblem problem : res.getErrors() ) {