Spring Boot / Kotlin中的自动装配泛型

import org.springframework.beans.factory.annotation.Autowired
import org.springframework.stereotype.Service

interface Repository<T> {
    fun findById(id: Long): T?
}

class UserRepository : Repository<User> {
    override fun findById(id: Long): User? {
        // 模拟数据库查询
        return User(id, "John Doe")
    }
}

data class User(val id: Long, val name: String)

@Service
class UserService @Autowired constructor(
    private val repository: Repository<User>
) {
    fun getUserById(id: Long): User? {
        return repository.findById(id)
    }
}

fun main() {
    val context = AnnotationConfigApplicationContext(AppConfig::class.java)
    val userService = context.getBean(UserService::class.java)
    val user = userService.getUserById(1)
    println(user)
}

@Configuration
@ComponentScan
class AppConfig

@Service
class UserService @Autowired constructor(
    private val repository: Repository<User>
) {
    fun getUserById(id: Long): User? {
        return repository.findById(id) as User?
    }
}

@Configuration
@ComponentScan(basePackages = ["com.example"])
class AppConfig