Java using Reflection to compare object for all field values

I have the following complex POJO class

public class Measure {

    private String id;
    private Float value;

    public String getId() { return id; }
    public void setId(String id) { this.id = id; }    

    public Float getValue() { return value; }
    public void setValue(Float value) { this.value = value; }

}

public class LineItem {

    private Integer lineNumber;      
    private MeasureF shipped;       
    private List<LineItem> lineItems;  


    public Integer getLineNumber() { return lineNumber; }
    public void setLineNumber(Integer lineNumber) { this.lineNumber = lineNumber; }

    public MeasureF getShipped() { return shipped; }
    public void setShipped(MeasureF shipped) { this.shipped = shipped; }

    public List<LineItem> getLineItems() { return lineItems; }
    public void setLineItems(List<LineItem> lineItems) { this.lineItems = lineItems; }

}

public class Base {

    private String tenantUid;
    private String sourceRecordId;
    private String uid;
    private String id;


    public String getTenantUid() { return tenantUid; }
    public void setTenantUid(String tenantUid) { this.tenantUid = tenantUid; }

    public String getSourceRecordId() { return sourceRecordId; }    
    public void setSourceRecordId(String sourceRecordId) { this.sourceRecordId = sourceRecordId; }

    public String getUid() { return uid; }   
    public void setUid(String uid) { this.uid = uid; }

    public String getId() { return id; }
    public void setId(String id) { this.id = id; }

}

public class Invoice extends Base {


    private String originUid;
    private String vehicleUid;
    private List<LineItem> lineItems;

    public String getOriginUid() { return originUid; }
    public void setOriginUid(String originUid) { this.originUid = originUid; }

    public String getVehicleUid() { return vehicleUid; }
    public void setVehicleUid(String vehicleUid) { this.vehicleUid = vehicleUid; }

    public List<LineItem> getLineItems() { return lineItems; }
    public void setLineItems(List<LineItem> lineItems) { this.lineItems = lineItems; }


}

I would like to use reflection to compare the values for all fields including child object and/or parent object and make update to one of the object. Something like this.

public Object updateIncomingObject(Object incomingObject, Object existingObject) {

    try {
        List<Field> incoming =  incomingObject.getClass().getDeclaredFields(); 
        for (Field incomingField : incoming) {

            incomingField.setAccessible(true);
            String incomingFieldName = incomingField.getName();
            String typeName = incomingField.getType().getName();

            if (incomingField.getType().IsSubType()) {
                // get field instance and then recursive call to updateIncomingObject();

            } else if (typeName.contains("java.util.List")) {
                // Loop list and recursive call to updateIncomingObject() 

            } else {
                Field existingField = getField(existingObject.getClass(), incomingFieldName);
                existingField.setAccessible(true);
                Object updatedTo = existingField.get(existingObject);
                if (updatedTo != null) {
                    incomingField.set(incomingObject, updatedTo);
                    String updateMsg = incomingFieldName + " Updated to : " + updatedTo;
                    LOGGER.debug(updateMsg);
                }
            }
        }
        return incomingObject;
    } catch (Exception e) {
        throw new Exception("updateIncomingObject() - " + e.getMessage());
    }
}

Can anyone tell me how to change the field object into a sub type object? Or filling the comment portion of the code? Or even better way to do this?

UPDATE: This is not a duplicate. I am looking for field to field update between to POJO objects with the same structure and the update is conditional. I didn't put the condition logic in updateIncomingObject() because I want to simplify things.

What I ma looking for is how to get to the fields of an field that is of non-primitive type, Such as Measure and LineItem as shown above.