ModelMapper: गोल यात्रा

मूल अभिभावक:

 @MappedSuperclass @Setter @EqualsAndHashCode @NoArgsConstructor @AllArgsConstructor public abstract class AbstractEntity implements Serializable { Long id; LocalDateTime created; LocalDateTime updated; @Id @GeneratedValue public Long getId() { return id; } @Column(name = "created", updatable = false) public LocalDateTime getCreated() { return created; } @Column(name = "updated", insertable = false) public LocalDateTime getUpdated() { return updated; } @PrePersist public void toCreate() { setCreated(LocalDateTime.now()); } @PreUpdate public void toUpdate() { setUpdated(LocalDateTime.now()); } } 

यूनिकॉर्न:

 @Entity @Table(name = "unicorns") @EqualsAndHashCode(callSuper = false) @Setter @AllArgsConstructor @NoArgsConstructor public class Unicorn extends AbstractEntity { private String name; private List<Droid> droids; private Color color; public Unicorn(String name, Color color) { this.name = name; this.color = color; } @Column(name = "name") public String getName() { return name; } @OneToMany(fetch = FetchType.EAGER, cascade = CascadeType.ALL, mappedBy = "unicorn") public List<Droid> getDroids() { return droids; } @Column(name = "color") public Color getColor() { return color; } } 

Droid:

 @Setter @EqualsAndHashCode(callSuper = false) @Entity @Table(name = "droids") @AllArgsConstructor @NoArgsConstructor public class Droid extends AbstractEntity { private String name; private Unicorn unicorn; private List<Cupcake> cupcakes; private Boolean alive; public Droid(String name, Unicorn unicorn, Boolean alive) { this.name = name; this.unicorn = unicorn; this.alive = alive; } public Droid(String name, Boolean alive) { this.name = name; this.alive = alive; } @Column(name = "name") public String getName() { return name; } @ManyToOne(fetch = FetchType.EAGER) @JoinColumn(name = "unicorn_id") public Unicorn getUnicorn() { return unicorn; } @OneToMany(fetch = FetchType.EAGER, cascade = CascadeType.ALL, mappedBy = "droid") public List<Cupcake> getCupcakes() { return cupcakes; } @Column(name = "alive") public Boolean getAlive() { return alive; } } 

कप केक:

 @Entity @Table(name = "cupcakes") @Setter @EqualsAndHashCode(callSuper = false) @AllArgsConstructor @NoArgsConstructor public class Cupcake extends AbstractEntity { private Filling filling; private Droid droid; @Column(name = "filling") public Filling getFilling() { return filling; } @ManyToOne(fetch = FetchType.EAGER) @JoinColumn(name = "droid_id") public Droid getDroid() { return droid; } public Cupcake(Filling filling) { this.filling = filling; } } 

मूल अभिभावक:

 @Data public abstract class AbstractDto implements Serializable { private Long id; @JsonFormat(shape = JsonFormat.Shape.STRING, pattern = "yyyy-MM-dd HH:mm:ss.SSS") LocalDateTime created; @JsonFormat(shape = JsonFormat.Shape.STRING, pattern = "yyyy-MM-dd HH:mm:ss.SSS") LocalDateTime updated; } 

UnicornDto:

 @EqualsAndHashCode(callSuper = true) @Data @NoArgsConstructor @AllArgsConstructor public class UnicornDto extends AbstractDto { private String name; private List<DroidDto> droids; private String color; } 

DroidDto:

 @EqualsAndHashCode(callSuper = true) @Data @NoArgsConstructor @AllArgsConstructor public class DroidDto extends AbstractDto { private String name; private List<CupcakeDto> cupcakes; private UnicornDto unicorn; private Boolean alive; } 

CupcakeDto:

 @EqualsAndHashCode(callSuper = true) @Data @NoArgsConstructor @AllArgsConstructor public class CupcakeDto extends AbstractDto { private String filling; private DroidDto droid; } 

 public interface Mapper<E extends AbstractEntity, D extends AbstractDto> { E toEntity(D dto); D toDto(E entity); } 

 public abstract class AbstractMapper<E extends AbstractEntity, D extends AbstractDto> implements Mapper<E, D> { @Autowired ModelMapper mapper; private Class<E> entityClass; private Class<D> dtoClass; AbstractMapper(Class<E> entityClass, Class<D> dtoClass) { this.entityClass = entityClass; this.dtoClass = dtoClass; } @Override public E toEntity(D dto) { return Objects.isNull(dto) ? null : mapper.map(dto, entityClass); } @Override public D toDto(E entity) { return Objects.isNull(entity) ? null : mapper.map(entity, dtoClass); } Converter<E, D> toDtoConverter() { return context -> { E source = context.getSource(); D destination = context.getDestination(); mapSpecificFields(source, destination); return context.getDestination(); }; } Converter<D, E> toEntityConverter() { return context -> { D source = context.getSource(); E destination = context.getDestination(); mapSpecificFields(source, destination); return context.getDestination(); }; } void mapSpecificFields(E source, D destination) { } void mapSpecificFields(D source, E destination) { } } 

  private Class<E> entityClass; private Class<D> dtoClass; AbstractMapper(Class<E> entityClass, Class<D> dtoClass) { this.entityClass = entityClass; this.dtoClass = dtoClass; } 

 @Component public class DroidMapper extends AbstractMapper<Droid, DroidDto> { private final ModelMapper mapper; private final UnicornRepository unicornRepository; @Autowired public DroidMapper(ModelMapper mapper, UnicornRepository unicornRepository) { super(Droid.class, DroidDto.class); this.mapper = mapper; this.unicornRepository = unicornRepository; } @PostConstruct public void setupMapper() { mapper.createTypeMap(Droid.class, DroidDto.class) .addMappings(m -> m.skip(DroidDto::setUnicornId)).setPostConverter(toDtoConverter()); mapper.createTypeMap(DroidDto.class, Droid.class) .addMappings(m -> m.skip(Droid::setUnicorn)).setPostConverter(toEntityConverter()); } @Override public void mapSpecificFields(Droid source, DroidDto destination) { destination.setUnicornId(getId(source)); } private Long getId(Droid source) { return Objects.isNull(source) || Objects.isNull(source.getId()) ? null : source.getUnicorn().getId(); } @Override void mapSpecificFields(DroidDto source, Droid destination) { destination.setUnicorn(unicornRepository.findById(source.getUnicornId()).orElse(null)); } } 

 @Component public class UnicornMapper extends AbstractMapper<Unicorn, UnicornDto> { @Autowired public UnicornMapper() { super(Unicorn.class, UnicornDto.class); } }