Class 不是抽象的，不实现抽象基础 class 成员

Question

我对这个 Kotlin 错误感到困惑，该错误与为从 maven 包导入的抽象 class 提供实现有关。

我有一个用 Kotlin 编写的 Maven 库，公开了一个名为 APIGatewayRequestHandler 的抽象 class。在导入库的应用程序中，我提供了抽象 class:

的实现

class GetWelcomeMessageHandler : APIGatewayRequestHandler<WelcomeMessage>()
    fun handleAPIGatewayRequest(input: com.amazonaws.services.lambda.runtime.events.APIGatewayProxyRequestEvent, context: com.amazonaws.services.lambda.runtime.Context?): WelcomeMessage {
        return WelcomeMessage()
    }
}

库中的反编译摘要 class 如下所示：

public abstract class APIGatewayRequestHandler<T> public constructor() : com.amazonaws.services.lambda.runtime.RequestHandler<com.amazonaws.services.lambda.runtime.events.APIGatewayProxyRequestEvent, T> {
    public abstract fun handleAPIGatewayRequest(input: com.amazonaws.services.lambda.runtime.events.APIGatewayProxyRequestEvent, context: com.amazonaws.services.lambda.runtime.Context?): T

    public open fun handleRequest(input: com.amazonaws.services.lambda.runtime.events.APIGatewayProxyRequestEvent?, context: com.amazonaws.services.lambda.runtime.Context?): T {
        /* compiled code */
    }
}

我收到以下错误：

Class 'GetWelcomeMessageHandler' is not abstract and does not implement abstract base class member
public abstract fun handleAPIGatewayRequest(input: APIGatewayProxyRequestEvent, context: Context?): WelcomeMessage

Answer 1

我认为您只是缺少一些 override 关键字。即，您的摘要 class 应该在 handleRequest 方法中包含它：

public abstract class APIGatewayRequestHandler<T> public constructor() : com.amazonaws.services.lambda.runtime.RequestHandler<com.amazonaws.services.lambda.runtime.events.APIGatewayProxyRequestEvent, T> {
    public abstract fun handleAPIGatewayRequest(input: com.amazonaws.services.lambda.runtime.events.APIGatewayProxyRequestEvent, context: com.amazonaws.services.lambda.runtime.Context?): T

    public override fun handleRequest(input: com.amazonaws.services.lambda.runtime.events.APIGatewayProxyRequestEvent?, context: com.amazonaws.services.lambda.runtime.Context?): T {
        /* compiled code */
    }
}

然后您的 GetWelcomeMessageHandler 应该在其 handleAPIGatewayRequest 方法中包含它：

class GetWelcomeMessageHandler : APIGatewayRequestHandler<WelcomeMessage>() { // <-- This curly brace was also missing
    override fun handleAPIGatewayRequest(input: com.amazonaws.services.lambda.runtime.events.APIGatewayProxyRequestEvent, context: com.amazonaws.services.lambda.runtime.Context?): WelcomeMessage {
        return WelcomeMessage()
    }
}

Class 不是抽象的，不实现抽象基础 class 成员

Class is not abstract and does not implement abstract base class member

kotlin

kotlin-interop