I try to use bbb to bind model properties to an swing gui. If I try to bind an JTextField to an int property everything works fine as long as the textfield contains an valid integer. if the textfield contains an string the binding failed and only in the log file you can find the reason. I want to show the user an message 'There is something wrong with your number' but there's no callback for me to get the information 'the mapping failed'. I try to use an Bindinglistener but the syncFailed method is never called. see comment in org.jdesktop.beansbinding.Binding.getSourceValueForTarget(Binding.java:844).