Execute Fault Message in Java Proxy

Hello,

I Call my Java Inbound Proxy and catch an exception.

How can i send now a Faul Message back to XI ?

} catch (Exception ex4) {
			ExchangeFaultData_Type faultData = new ExchangeFaultData_Type();
			faultData.setFaultText(ex4.getMessage());
			ErrorReturn_Type errorReturn = new ErrorReturn_Type();
			errorReturn.setStandard(faultData);
		}

What should i do ?

Regards,

Robin