How to convert nested objects into nested DTOs using ModelMapper?

Question

I am facing issue when I am trying to use ModelMapper to convert nested java objects into nested DTO's. Getting null for child dto's in parent dto object. Following are the code snippets.

Entity Classes :

public class User {
    private String name;
    private Address address;
    private Product product;
}

public class Address { 
    private String area;
    private String city;
}

public class Product {
    private Integer productId;
    private String productName;
    private Double productPrice;
 } 

DTO's Classes :

public class UserDTO {
   private String name;
   private AddressDTO address;
   private ProductDTO product;
}

public class AddressDTO {
   private String area;
   private String city;
}

public class ProductDTO {
   private Integer productId;
   private String productName;
   private Double productPrice;
}

here is the mapper code :

ModelMapper mapper = new ModelMapper();
mapper.getConfiguration().setMatchingStrategy(MatchingStrategies.LOOSE);
UserDTO userDTO = mapper.map(user, UserDTO.class);
System.out.println("Output User DTO : " + userDTO );

Output :

Output User DTO : UserDTO [name=xyz, address=null, product=null]

Here I want to convert User entity into UserDTO dto. I am getting null values for address and product DTO's. What exactly I am missing here ? Does anyone have any idea ?

Note : I have added getters, Setters and toString() methods in entity and DTO's.

Answer 1

Here I found solution for nested DTO to Entity and vice versa conversions, I was missing some ModelMapper configurations that I have added below.

mapper.getConfiguration()
      .setFieldMatchingEnabled(true)
      .setFieldAccessLevel(AccessLevel.PRIVATE)
      .setMatchingStrategy(MatchingStrategies.STANDARD);