Map String Array into a POJO with Dozer

Question

I'm trying to convert a List<String[]> into List<Object> using Dozer but unable to map the index values to the property fields using mapper API configuration .

How can I map the members of the String[] into individual object fields with each index targeting a specific field? (eg [0] -> name , and [1] -> role )

DozerBeanMapper mapper = new DozerBeanMapper();
BeanMappingBuilder builder = new BeanMappingBuilder() {
    @Override
    protected void configure() {
        mapping(String[].class, User.class)
            .fields(this_(), "name"); // HOW do I specify index?**
    }
};
mapper.addMapping(builder);

List<String[]> users = new ArrayList<>();
String[] user1 = {"Jill", "SDE"};
String[] user2 = {"Jack", "PM"};
users.add(user1);
users.add(user2);
List<User> userList = mapObjects(mapper, users, User.class);

where mapObjects() is;

private static <T1, T2> List<T2> mapObjects(DozerBeanMapper mapper, List<T1> sourceList, Class<T2> destinationClazz) {
    try {
        return sourceList.stream()
                .map(i -> mapper.map(i, destinationClazz))
                .collect(Collectors.toList());
    } catch (Exception e) {
        ...
    }
    return new ArrayList<>();
}

and User class;

class User {
    String name;
    String role;

    // getter & setter
}

Answer 1

It worked perfectly with the following configuration;

DozerBeanMapper mapper = new DozerBeanMapper();
BeanMappingBuilder builder = new BeanMappingBuilder() {
    @Override
    protected void configure() {
        mapping(String[].class, User.class)
                .fields(this_(), "name", FieldsMappingOptions.customConverterId("arrToName"))
                .fields(this_(), "role", FieldsMappingOptions.customConverterId("arrToRole"));
    }
};
final Map<String, CustomConverter> customConverterMap = new HashMap<>();
customConverterMap.put("arrToName", new ArrToNameConverter());
customConverterMap.put("arrToRole", new ArrToRoleConverter());
mapper.setCustomConvertersWithId(customConverterMap);
mapper.addMapping(builder);

Utilizing a logic where String[] is mapped into name and role fields separately via custom converters, which are targeting a specific index of the input String[] . With dozer , you can essentially define custom converters and assign them an id, and refer them with those ids inside of field mappings FieldsMappingOptions.customConverterId("{id}")

where ArrToNameConverter ;

public class ArrToNameConverter extends DozerConverter<String[], String> {

    public ArrToNameConverter() {
        super(String[].class, String.class);
    }

    @Override
    public String convertTo(String[] strings, String user) {
        return strings[0];
    }

    @Override
    public String[] convertFrom(String user, String[] strings) {
        return new String[0];
    }
} 

and ArrToRoleConverter ;

public class ArrToRoleConverter extends DozerConverter<String[], String> {

    public ArrToRoleConverter() {
        super(String[].class, String.class);
    }

    @Override
    public String convertTo(String[] strings, String user) {
        return strings[1];
    }

    @Override
    public String[] convertFrom(String user, String[] strings) {
        return new String[0];
    }
} 

With the above mapper , I was able to get the following result;

[User(name=Jill, role=SDE), User(name=Jack, role=PM)]