I try to use BeanUtils from commons project. I want to copy properties from one bean to another. The problem I have is when the source bean has a java.lang.String property which is null and the target bean has property of java.lang.Long. Using BeanUtils.copyProperties(target, source) set the target's property to 0 (zero). But I do not need this. I need the property to stay null also as in the source bean.