Kotlin，将一个类映射到另一个类

data class UserEntity(val id: Int, val name: String, val email: String)
data class UserDTO(val userId: Int, val userName: String, val userEmail: String)

fun UserEntity.toUserDTO(): UserDTO {
    return UserDTO(
        userId = this.id,
        userName = this.name,
        userEmail = this.email
    )
}

// 使用示例
val userEntity = UserEntity(1, "John Doe", "john.doe@example.com")
val userDTO = userEntity.toUserDTO()
println(userDTO) // 输出: UserDTO(userId=1, userName=John Doe, userEmail=john.doe@example.com)

<dependency>
    <groupId>org.mapstruct</groupId>
    <artifactId>mapstruct</artifactId>
    <version>1.4.2.Final</version>
</dependency>

import org.mapstruct.Mapper
import org.mapstruct.Mapping
import org.mapstruct.factory.Mappers

@Mapper
interface UserMapper {
    @Mapping(source = "id", target = "userId")
    @Mapping(source = "name", target = "userName")
    @Mapping(source = "email", target = "userEmail")
    fun userEntityToUserDTO(userEntity: UserEntity): UserDTO
}

// 实例化映射器
val userMapper = Mappers.getMapper(UserMapper::class.java)

// 使用示例
val userDTO = userMapper.userEntityToUserDTO(userEntity)
println(userDTO) // 输出: UserDTO(userId=1, userName=John Doe, userEmail=john.doe@example.com)