[FIXED] Spring Bean copy properties ignore child's object null values

Issue

I am trying to copy one object's property values to another object. Below mentioned sample works good. But when tried with child level properties copy it is not ignoring null values. I would like to ignore null values in parent and child as well.

How can I ignore child level null values while copying object from one to another ?

I am using Spring Bean utils. If the solution available in Apache utils also fine.

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);
}

// then use Spring BeanUtils to copy and ignore null using our function
public static void myCopyProperties(Object src, Object target) {
    BeanUtils.copyProperties(src, target, getNullPropertyNames(src));
}


 class Person {
  private String name;
  private Address address;

  public static class Address {
     private String apt;
     private String state;
     private ContactInfo contactInfo;

     public static class ContactInfo {
        private String primaryEmail;
        private String secEmail;      
     }
  }
}

Solution

com.demo.test is my project package. if any object belongs to my package , I am doing regression to copy the value. it works.

public static String[] getNullPropertyNames (Object source, Object target) {
    final BeanWrapper src = new BeanWrapperImpl(source);
    final BeanWrapper targetBean = new BeanWrapperImpl(target);
    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());
        }else  {
            Class<?> accessor = src.getPropertyType(pd.getName());
            String cname = accessor.getCanonicalName();
            if(cname.contains("com.demo.test")) {
                Object targetVal = targetBean.getPropertyValue(pd.getName());
               if(targetVal  != null) {
                BeanUtils.copyProperties(srcValue,targetVal , getNullPropertyNames(srcValue,targetVal));
                emptyNames.add(pd.getName());
                  }
            }
        }
    }

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

Answered By - Gnana
Answer Checked By - Mary Flores (JavaFixing Volunteer)