mapstruct

Multi-layered applications often require to map between different object models (e.g. entities and DTOs)

​

https://mapstruct.org/

​

DTO와 Entity class의 변수값을 mapping해줄 때 사용하는 것 같다.

​

gradle

dependencies { ... implementation 'org.mapstruct:mapstruct:1.5.3.Final' annotationProcessor 'org.mapstruct:mapstruct-processor:1.5.3.Final' }

reference guide

https://mapstruct.org/documentation/stable/reference/html/

MapStruct 1.5.3.Final Reference Guide

Preface This is the reference documentation of MapStruct, an annotation processor for generating type-safe, performant and dependency-free bean mapping code. This guide covers all the functionality provided by MapStruct. In case this guide doesn’t answer all your questions just join the MapStruct Gi…

@Mapping 애노테이션을 사용해서 작성하는 것으로 보이고, build-time에 구현체가 생성되는 것 같다.

@Mapper public interface CarMapper { @Mapping(target = "manufacturer", source = "make") @Mapping(target = "seatCount", source = "numberOfSeats") CarDto carToCarDto(Car car); @Mapping(target = "fullName", source = "name") PersonDto personToPersonDto(Person person); }

구현 코드는 다음과 같이 만들어지는 것 같다.

// GENERATED CODE public class CarMapperImpl implements CarMapper { @Override public CarDto carToCarDto(Car car) { if ( car == null ) { return null; } CarDto carDto = new CarDto(); if ( car.getFeatures() != null ) { carDto.setFeatures( new ArrayList( car.getFeatures() ) ); } carDto.setManufacturer( car.getMake() ); carDto.setSeatCount( car.getNumberOfSeats() ); carDto.setDriver( personToPersonDto( car.getDriver() ) ); carDto.setPrice( String.valueOf( car.getPrice() ) ); if ( car.getCategory() != null ) { carDto.setCategory( car.getCategory().toString() ); } carDto.setEngine( engineToEngineDto( car.getEngine() ) ); return carDto; } @Override public PersonDto personToPersonDto(Person person) { //... } private EngineDto engineToEngineDto(Engine engine) { if ( engine == null ) { return null; } EngineDto engineDto = new EngineDto(); engineDto.setHorsePower(engine.getHorsePower()); engineDto.setFuel(engine.getFuel()); return engineDto; } }

그 밖의 설정들은 많이 있는 것으로 보인다. reference 문서를 참고해보자.

​

product class

public class Product { private int productId; private String name; private int weight; private String serviceAddress; public Product() { productId = 0; name = null; weight = 0; serviceAddress = null; } public Product(int productId, String name, int weight, String serviceAddress) { this.productId = productId; this.name = name; this.weight = weight; this.serviceAddress = serviceAddress; } public int getProductId() { return productId; } public String getName() { return name; } public int getWeight() { return weight; } public String getServiceAddress() { return serviceAddress; } public void setProductId(int productId) { this.productId = productId; } public void setName(String name) { this.name = name; } public void setWeight(int weight) { this.weight = weight; } public void setServiceAddress(String serviceAddress) { this.serviceAddress = serviceAddress; } }

product mapper class

@Mapper(componentModel = "spring") public interface ProductMapper { @Mappings({ @Mapping(target = "serviceAddress", ignore = true) }) Product entityToApi(ProductEntity entity); @Mappings({ @Mapping(target = "id", ignore = true), @Mapping(target = "version", ignore = true) }) ProductEntity apiToEntity(Product api); }

product entity class

@Document(collection="products") public class ProductEntity { @Id private String id; @Version private Integer version; @Indexed(unique = true) private int productId; private String name; private int weight; public ProductEntity() { } public ProductEntity(int productId, String name, int weight) { this.productId = productId; this.name = name; this.weight = weight; } public String getId() { return id; } public Integer getVersion() { return version; } public int getProductId() { return productId; } public String getName() { return name; } public int getWeight() { return weight; } public void setId(String id) { this.id = id; } public void setVersion(Integer version) { this.version = version; } public void setProductId(int productId) { this.productId = productId; } public void setName(String name) { this.name = name; } public void setWeight(int weight) { this.weight = weight; } }

​