How to use Java 8 Optional for mentioned situation?

Mahesh :

Lets say I have a pojo Medicine,

class Medicine{
    private String xmedicine;
    private String ymedicine;
    private String zmedicine;

    //getter and setter here....
}

Below API used to collect medicine if medicine is not null.

public List<Map<String, Object>> gettMedicine(Medicine medicine) {
        List<Map<String, Object>> detailsList = null;

        List<Integer> list = new ArrayList<>();

        if(null != medicine.getXmedicine()){
            list.add(medicine.getXmedicine());                              
        }
        if(null != medicine.getYmedicine()){
            list.add(medicine.getYmedicine());                              
        }
        if(null != medicine.getZmedicine()){
            list.add(medicine.getZmedicine());                              
        }
        if(!CollectionUtils.isEmpty(list)) {
            detailsList = //calling other API to get details from list;
        }
        return detailsList;
}

Is it preferred to use java 8 Optional here to eliminate NullPointerException as I have multiple null checks making my code boilerplate.

If yes then can you please suggest how can I use Optional here?

Adrian :

You should not use Optional for fields in a class or to replace it with null checks like in your ifs. In this case you can do the following:

Stream.of(medicine.getXmedicine(), medicine.getYmedicine(), medicine.getZmedicine())
       .filter(Objects::nonNull)
       .collect(Collectors.toList())