Today we will see how to implement a ModelMapper that allows us, for example, to transform an object with many properties into a smaller object with fewer properties. This transformation can be useful for example when we need leaner objects, perhaps in a list, or when we want to expose only some properties of an object, leaving the others hidden in logic.
We have this 2 objects:
class FullDTO {
long id;
String title;
String author;
String email;
String password;
String webSite;
int hiddenInformation;
boolean isForAdmin;
// assume getters and setters
}
class LightDTO {
long id;
String title;
String author;
// assume getters and setters
}
In the class that needs mapping we can create a mapping method and use it ( mapToLight() ):
import org.modelmapper.ModelMapper;
class UsingModelMapper {
@Autowired private ModelMapper modelMapper;
public LightDTO mapToLight(FullDTO fullDTO) {
return modelMapper.map(aSource, LightDTO.class);
}
}
Now we need a ModelMapper bean to be wired for statically import it in all our application.
To configure ModelMapper in the application:
// MyBEConfig.java
import org.modelmapper.ModelMapper;
@Configuration
@EnableWebMvc
public class MyApplicationConfig implements WebMvcConfigurer {
@Bean
public ModelMapper modelMapper() {
return new ModelMapper();
}
}
Let’s not forget to import the library we need. To install ModelMapper with Maven, we can say:
<dependency>
<groupId>org.modelmapper</groupId>
<artifactId>modelmapper</artifactId>
<version>2.3.2</version>
</dependency>
If you haven’t Spring Boot you can use it creating a new ModelMapper() object but prefear the first method:
ModelMapper modelMapper = new ModelMapper();
That’s all for now.
Try it at home!
