I've two objects objclient and objserver of the same type Object,(i.e. Dog, Cat..)

when I receive objclient in my endpoint I need to replace its attributes with the non-null ones in objserver without doing explicitly, for example :

private void eraser(Object clientObject, Object serverObject){
  //set only non null attributes of serverObject to clientObject
}

CodePudding user response：

You can use e.g. ModelMapper if you want to map values between different java objects without explicitly having to map every single field.

CodePudding user response：

BeanUtils.copyProperties is very common in spring-boot projects, we can use it with passing ignoreProperties (null case) & we can find the null case by using a custom method like below:

    private ClientObject eraser(ClientObject clientObject, ServerObject serverObject){
        BeanUtils.copyProperties(serverObject, clientObject, getNullPropertyNames(serverObject));
        return clientObject;
    }

    public static String[] getNullPropertyNames (Object source) {
        final BeanWrapper src = new BeanWrapperImpl(source);
        java.beans.PropertyDescriptor[] pds = src.getPropertyDescriptors();

        Set<String> emptyNames = new HashSet<String>();
        for(java.beans.PropertyDescriptor pd : pds) {
            Object srcValue = src.getPropertyValue(pd.getName());
            if (srcValue == null) emptyNames.add(pd.getName());
        }

        String[] result = new String[emptyNames.size()];
        return emptyNames.toArray(result);
    }

It will set only non null attributes of serverObject to clientObject.