我在Kotlin（Ktor框架）中遇到了一个破碎单例的问题。
问题特别是Ktor Development mode。当它被禁用时，一切都正常工作...
这两个调用打印出不同的示例！我很惊讶没有发现任何其他人提到这个问题..这是无用的！
有人有同样的问题吗？

# Application.kt

object Singleton {
    fun printInstanceId() {
        println("--> This is Singleton ${toString()}")
    }
}

fun main() {
    Singleton.printInstanceId() # <-- instance com.mallgroup.Singleton@27c170f0

    embeddedServer(Netty,port = 8080,module = Application::bootstrap).start(wait = true)
}

fun Application.bootstrap() {
    Singleton.printInstanceId() # <-- there is another instance!!! com.mallgroup.Singleton@18cebaa5

终端输出

❯ sh gradlew run

> Configure project :
Environment: development , isDevelopment: true

> Task :compileKotlin
'compileJava' task (current target is 19) and 'compileKotlin' task (current target is 1.8) jvm target compatibility should be set to the same Java version.
By default will become an error since Gradle 8.0+! Read more: https://kotl.in/gradle/jvm/target-validation
Consider using JVM toolchain: https://kotl.in/gradle/jvm/toolchain

> Task :run
!!! This is Singleton com.mallgroup.Singleton@27c170f0
...
2023-01-04 15:28:53.352 [main] DEBUG ktor.application - Java Home: /Users/whipstercz/Library/Java/JavaVirtualMachines/openjdk-19.0.1/Contents
2023-01-04 15:28:53.354 [main] DEBUG ktor.application - Class Loader: jdk.internal.loader.ClassLoaders$AppClassLoader@5b37e0d2: [...]
2023-01-04 15:28:53.370 [main] DEBUG ktor.application - Watching /Users/whipstercz/Desktop/mal/ktor-autoreload/build/classes/kotlin/main/com/mallgroup/plugins for changes.
...
!!! This is Singleton com.mallgroup.Singleton@18cebaa5
2023-01-04 15:28:53.897 [main] INFO  ktor.application - Application started in 0.715 seconds.
2023-01-04 15:28:54.086 [main] INFO  ktor.application - Responding at http://0.0.0.0:8080

这怎么可能是两个不同的例子呢？
我已经尝试了甚至不同的实现单例与相同的结果。

class Singleton private constructor() {
    companion object {
        @Volatile
        private lateinit var instance: Singleton
        fun getInstance(): Singleton {
            synchronized(this) {
                if (!::instance.isInitialized) {
                    instance = Singleton()
                }
                return instance
            }
        }
    }

    fun printInstanceId() {
        println("This is Singleton ${toString()}")
    }
}