Orika Mapper - MapperFacade 初始化后无法注册转换器

Question

我在 spring 引导应用程序中使用 Orika Mapper API 创建了一个 class 来复制 bean 属性，如下所示：

public class ObjectMapper {

    private static MapperFactory mapperFactory = new DefaultMapperFactory.Builder().build();

    public static ClientEntity toClientEntity(ClientDTO clientDTO) {
        BoundMapperFacade<ClientDTO, ClientEntity> boundMapper = mapperFactory.getMapperFacade(ClientDTO.class, ClientEntity.class);
        return boundMapper.map(clientDTO);
    }   

    public static UserEntity toUserEntity(UserDTO userDTO) {
        mapperFactory.getConverterFactory().registerConverter(new PassThroughConverter(LocalDate.class));
        mapperFactory.getConverterFactory().registerConverter(new PassThroughConverter(LocalTime.class));
        BoundMapperFacade<UserDTO, UserEntity> boundMapper = mapperFactory.getMapperFacade(UserDTO.class, UserEntity.class);
        return boundMapper.map(userDTO);
    }
}

UserEntity 和 UserDTO POJO classes 具有 JAVA 8 个 LocalDate 和 LocalTime 属性，因此为 mapperFactory 注册了转换器。这第一次工作正常，但在连续调用时会抛出以下异常：

java.lang.IllegalStateException: Cannot register converters after MapperFacade has been initialized
    at ma.glasnost.orika.converter.DefaultConverterFactory.registerConverter(DefaultConverterFactory.java:192) ~[orika-core-1.4.6.jar:na]
    at ma.glasnost.orika.impl.DefaultMapperFactory$ConverterFactoryFacade.registerConverter(DefaultMapperFactory.java:1614) ~[orika-core-1.4.6.jar:na]

我理解这是因为转换器在 MapperFacade 初始化后被注册。如何解决这个问题？如何在初始化前注册转换器？

Answer 1

在提供的代码段中，您尝试在每次调用 toUserEntity() 时注册转换器。因此，第一次调用会成功，但第二次调用会失败，因为 MapperFacade 在第一次调用期间已经初始化。

您可以像这样将转换器注册从映射方法移动到静态块：

private static MapperFactory mapperFactory = new DefaultMapperFactory.Builder().build();
static {
    mapperFactory.getConverterFactory().registerConverter(new PassThroughConverter(LocalDate.class));
    mapperFactory.getConverterFactory().registerConverter(new PassThroughConverter(LocalTime.class));
}

此外，您可能更愿意将 BoundMapperFacade 移动到静态字段以避免不必要的 getMapperFacade 调用，如下所示：

private static BoundMapperFacade<ClientDTO, ClientEntity> clientBoundMapper 
                     = mapperFactory.getMapperFacade(ClientDTO.class, ClientEntity.class);
private static BoundMapperFacade<UserDTO, UserEntity> userBoundMapper 
                     = mapperFactory.getMapperFacade(UserDTO.class, UserEntity.class);

所以映射方法将变成简单的一行：

public static ClientEntity toClientEntity(ClientDTO clientDTO) {
    return clientBoundMapper.map(clientDTO);
}   

public static UserEntity toUserEntity(UserDTO userDTO) {
    return userBoundMapper.map(userDTO);
}

Orika Mapper - MapperFacade 初始化后无法注册转换器

Orika Mapper - Cannot register converters after MapperFacade has been initialized

spring-boot

java-8

mapping

orika