if (exchange.getUnitOfWork() == null) {
UnitOfWork unitOfWork;
// If there is no existing UoW, then we should start one and
// terminate it once processing is completed for the exchange.
if (exchange.getContext().isUseMDCLogging()) {
unitOfWork = new MDCUnitOfWork(exchange);
} else {
unitOfWork = new DefaultUnitOfWork(exchange);
}
final UnitOfWork uow = unitOfWork;