Question

As per the requirement, I have parsed an XML file and set data into these two DTO classes:

public class DetailsDTO implements java.io.Serializable {
private String      userid;
private String      accountnum;
private Customer    customer;
// setters and getters

public class Customer implements Serializable
{
private String            street;
private String            country;
// setters and getters

After adding data of the Customer class to DetailsDTO, I added this DetailsDTO to an ArrayList as shown:

List list = new ArrayList();
// and added these DetailsDTO class to an ArrayList
list.add(detailsDTO)

Now there is a Master DTO called as WholeDetails which consists of all variables defined in various DTO classes as shown.

class WholeDetails
{
private String   userid;
private String   accountnum;
private String   street;
private String   country;
}

Now, as you see, all the data is aviable within the ArrayList.

How can I extract the contents from ArrayList and map it to the WholeDetails?

Answer 1

You will have to do the mapping e.g.

List<DetailsDTO> list = new ArrayList<DetailsDTO>();    
// and added these DetailsDTO class to an ArrayList   
list.add(detailsDTO);  

List<WholeDetails> wholeDTOList = new ArrayList<WholeDetails>();   
for(DetailsDTO dto:list){  
  WholeDetails whole = new WholeDetails();  
  whole.setUserid(dto.getUserid());  
  whole.setAccountNum(dto.getAccountNum());  
  whole.setStreet(dto.getCustomer().getStreet());  
  whole.setCountry(dto.getCustomer().getCountry());  
  wholeDTOList.add(whole);

}   

If you like it to be more short you could create an adapter class that maps the DetailsDTO to the WholeDetailsDTO and add the result object to the list