MapStruct for automated DTO to Entity mapping and vice versa
2 min readDec 22, 2021
This code example demonstrates the use of MapStruct when we need to convert basic objects into DTOs.
We start by adding the MapStruct dependencies to a Spring project. Here we use a new project, but the procedure is the same for mature projects as well.
pom.xml
<dependencies>
<dependency>
<groupId>org.mapstruct</groupId>
<artifactId>mapstruct-jdk8</artifactId>
<version>1.2.0.Final</version>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.5.1</version>
<configuration>
<source>1.8</source>
<target>1.8</target>
<annotationProcessorPaths>
<path>
<groupId>org.mapstruct</groupId>
<artifactId>mapstruct-processor</artifactId>
<version>1.2.0.Final</version>
</path>
</annotationProcessorPaths>
</configuration>
</plugin>
</plugins>
</build>
For each entity we need a Mapper interface:
UtilizatorUtilizatorDTOMapper Interface@Mapper
public interface UtilizatorUtilizatorDTOMapper {
UtilizatorUtilizatorDTOMapper INSTANCE = Mappers.getMapper(UtilizatorUtilizatorDTOMapper.class);
UtilizatorDTO objToDto(Utilizator utilizator);
Utilizator dtoToObj(UtilizatorDTO destination);
}
Now we can build the entity and DTO:
Utilizator Entitypublic class Utilizator {
private String name;
private String address;
public Utilizator() {
}
public Utilizator(String name, String address) {
this.name = name;
this.address = address;
}
//getters & setters
}UtilizatorDTOpublic class UtilizatorDTO {
private String name;
public UtilizatorDTO() {
}
public UtilizatorDTO(String name) {
this.name = name;
}
//getters & setters
}
For demonstration purposes we are going to use a Controller class to evaluate our Mapper.
Controller class@RestController
class Controller {
@GetMapping(value = "/mapstruct_simple_obj_to_dto.action")
public UtilizatorDTO mapstructSimpleObjToDto() {
Utilizator utilizator = new Utilizator("Gabi", "Krakovia 9A");
UtilizatorDTO utilizatorDTO = UtilizatorUtilizatorDTOMapper.INSTANCE.objToDto(utilizator);
return utilizatorDTO;
}
@GetMapping(value = "/mapstruct_simple_dto_to_obj.action")
public Utilizator mapstructSimpleDtoToObj() {
UtilizatorDTO utilizatorDTO = new UtilizatorDTO("Gabi");
Utilizator utilizator = UtilizatorUtilizatorDTOMapper.INSTANCE.dtoToObj(utilizatorDTO);
return utilizator;
}
}
Originally published at https://www.weinspire.tech on October 08, 2019.