'Parsing two objects into one

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
}
javajsonspring-bootjackson


Solution 1:[1]

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

Solution 2:[2]

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.

Solution 3:[3]

Actually the best solution comparing to @Rakib's one is:

private void erase(Object clientObject, Object defaultObject) throws IllegalAccessException, NoSuchFieldException {
            Field[] Fields = defaultObject.getClass().getDeclaredFields();
        
            for (Field field : Fields) {
                field.setAccessible(true);
                Object value = field.get(defaultObject);
                if(value !=null)
                    field.set(clientObject,value);
            }
    }

Sources

This article follows the attribution requirements of Stack Overflow and is licensed under CC BY-SA 3.0.

Source: Stack Overflow

Solution Source
Solution 1 tbjorch
Solution 2 Rakib Hasan
Solution 3 Abdessalam Idali Lahcen

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