在我正在处理的示例 Spring Boot webapp 中，使用 Orika 将实体映射到 DTO 时，我遇到了一个奇怪的 ClassCastException。当我尝试在嵌入式 Tomcat 中对已部署的应用程序进行映射时出现异常，但我可以在 JUnit 测试上下文中很好地进行映射。这是相关的类（它们都很简单）：
JPA 实体：
@Entity
public class Position {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private Integer id;
private String name;
// getters/setters...
}
DTO：
public class PositionDto {
private Integer id;
private String name;
// getters/setters...
}
休息控制器：
@RestController
public class PositionController {
@Autowired
private PositionService positionService;
@RequestMapping("/position")
public PositionDto get() {
final PositionDto positionDto = positionService.getPosition(1);
return positionDto;
}
}
服务等级：
@Service
public class PositionServiceImpl implements PositionService {
@Autowired
private PositionRepository positionRepository;
@Autowired
private OrikaBeanMapper mapper;
@Transactional(readOnly = true)
@Override
public PositionDto getPosition(final Position.ID id) {
// This returns a populated Position object with id=1 and name = "Creator"
final Position position = positionRepository.findOne(id.getId());
// This is where the mapping occurs
return mapper.map(position, PositionDto.class);
}
}
OrikaBeanMapper 类：
@Component
public class OrikaBeanMapper extends ConfigurableMapper implements ApplicationContextAware {
public OrikaBeanMapper() {
super(false);
}
@Override
protected void configureFactoryBuilder(final DefaultMapperFactory.Builder factoryBuilder) {
factoryBuilder.mapNulls(false);
}
// Omitted non-important methods
}
这是 ClassCastException 的堆栈跟踪：
Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed; nested exception is ma.glasnost.orika.MappingException: While attempting the following mapping:
sourceClass = class com.dlizarra.startuphub.position.Position
destinationType = com.dlizarra.startuphub.position.PositionDto
resolvedStrategy = InstantiateAndUseCustomMapperStrategy<Position, PositionDto> {customMapper: GeneratedMapper<Position, PositionDto> {usedConverters: [], usedMappers: [], usedMapperFacades: [], usedTypes: [] }, unenhancer: ma.glasnost.orika.unenhance.BaseUnenhancer@73c3e10e, objectFactory: DefaultConstructorObjectFactory<PositionDto>}
Error occurred: java.lang.ClassCastException: com.dlizarra.startuphub.position.Position cannot be cast to com.dlizarra.startuphub.position.Position
-----begin dump of current state-----------------------------
Registered object factories: 1 (approximate size: 110.8 kB)
[PositionDto] : {Position=DefaultConstructorObjectFactory<PositionDto>}
-------------------------------------------------------------------------------
Registered mappers: 1 (approximate size: 17,643.0 kB)
[0] : GeneratedMapper<Position, PositionDto> {usedConverters: [], usedMappers: [], usedMapperFacades: [], usedTypes: [] }
-------------------------------------------------------------------------------
Registered concrete types: 5 (approximate size: 294.3 kB)
[interface java.util.List] : ArrayList<Object>
[interface java.util.Set] : LinkedHashSet<Object>
[interface java.util.Collection] : ArrayList<Object>
[interface java.util.Map] : LinkedHashMap<Object, Object>
[interface java.util.Map$Entry] : MapEntry<Object, Object>
-------------------------------------------------------------------------------
Resolved strategies: 1 (approximate size: 19,850.8 kB)
{source: Position, dest: PositionDto, in-place:false}: InstantiateAndUseCustomMapperStrategy<Position, PositionDto>
{customMapper: GeneratedMapper<Position, PositionDto> {usedConverters: [], usedMappers: [], usedMapperFacades: [], usedTypes: [] }, unenhancer:
ma.glasnost.orika.unenhance.BaseUnenhancer@73c3e10e, objectFactory:
DefaultConstructorObjectFactory<PositionDto>}
-------------------------------------------------------------------------------
Unenhance strategy: ma.glasnost.orika.unenhance.BaseUnenhancer@73c3e10e
-----end dump of current state-------------------------------] with root cause
java.lang.ClassCastException: com.dlizarra.startuphub.position.Position cannot be cast to com.dlizarra.startuphub.position.Position
at ma.glasnost.orika.generated.Orika_PositionDto_Position_Mapper43322711137530$0.mapAtoB(Orika_PositionDto_Position_Mapper43322711137530$0.java) ~[orika-core-1.4.6.jar:na]
at ma.glasnost.orika.impl.mapping.strategy.UseCustomMapperStrategy.map(UseCustomMapperStrategy.java:67) ~[orika-core-1.4.6.jar:na]
at ma.glasnost.orika.impl.MapperFacadeImpl.map(MapperFacadeImpl.java:742) ~[orika-core-1.4.6.jar:na]
我真的不知道这里发生了什么。我不明白它试图将位置转换为位置。每个实体/dto 类都会发生这种情况，而不仅仅是位置。
当我对任何方法进行单元测试时，我可以毫无问题地映射任何这些类，它运行良好并且所有字段都正确映射，所以我认为这不是 Orika 配置问题。仅当我将 webapp 部署在嵌入式 Tomcat 中并且在 rest 控制器方法中调用映射方法时才会发生异常。
这是一个简单的 Spring Boot 应用程序，这是我在其中编写的第一个 rest 端点。也许我在配置中遗漏了一些东西（我有 @EnableAutoConfiguration 所以没有那么多配置），但我猜不出是什么让 Orika 抛出这个异常。
任何关于这里可能发生的事情的想法或提示将不胜感激。
谢谢！