解决 Kotlin 中的意外覆盖错误 [英] Resolving Accidental Override errors in Kotlin

问题描述

我最近开始使用 Kotlin 过期，并使用 Kotlin 启动了一个 Spring Boot 宠物项目.

I've recently started expirementing with Kotlin and started a Spring Boot pet project using Kotlin.

我正在尝试将自定义用户域对象集成到 Spring Security，因此想要实现 UserDetails 界面.

I'm trying to integrate a custom User domain object to Spring Security and thus want to implement the UserDetails inteface.

鉴于我的域用户对象如下:

Given my domain User object below:

import org.springframework.data.annotation.Id as DocumentId
import org.springframework.data.mongodb.core.mapping.Document
import org.springframework.security.core.GrantedAuthority
import org.springframework.security.core.authority.AuthorityUtils
import org.springframework.security.core.userdetails.UserDetails

@Document
data class User(@DocumentId val id: String? = null,
                val username: String = "",
                val password: String = "",
                val email: String = "",
                val name: String? = null,
                val surname: String? = null) : UserDetails {

    override fun isCredentialsNonExpired(): Boolean = true

    override fun isAccountNonExpired(): Boolean = true

    override fun isAccountNonLocked(): Boolean = true

    override fun getAuthorities(): MutableCollection<out GrantedAuthority> = AuthorityUtils.createAuthorityList("USER")

    override fun isEnabled(): Boolean = true
}

我收到以下错误:

1. 意外覆盖:以下声明具有相同的JVM签名 (getUsername()Ljava/lang/String;): public final fun <;get-username>(): Kotlin.String, public abstract fun getUsername(): Kotlin.String!

1. Accidental override: The following declarations have the same JVM signature (getUsername()Ljava/lang/String;): public final fun < get-username>(): Kotlin.String, public abstract fun getUsername(): Kotlin.String!

意外覆盖:以下声明具有相同的JVM签名 (getPassword()Ljava/lang/String;): public final fun <get-password>(): Kotlin.String, public abstract fun getPassword(): Kotlin.String!

Accidental override: The following declarations have the same JVM signature (getPassword()Ljava/lang/String;): public final fun < get-password>(): Kotlin.String, public abstract fun getPassword(): Kotlin.String!

因为我的 User 类已经有一个方法 getUsername(): Kotlin.String 也实现了方法 getUsername(): Kotlin.String！?

Since my User class already has a method getUsername(): Kotlin.String also implement the method getUsername(): Kotlin.String! ?

除了使用 @JvmName 在属性的 getter 和 setter 上?

How am I supposed to resolve such an error, other than using the @JvmName on the property's getter and setter?

推荐答案

这里的问题是，从 Kotlin 的角度来看，属性 getter 不可能覆盖来自超类型的函数.要解决此问题，您可以通过将属性设为 private 并手动从超类型实现所需的方法来阻止编译器生成 getter，例如:

The problem here is that it's impossible for a property getter to override a function from a supertype, from Kotlin's point of view. To workaround it, you can prevent the compiler from generating getters by making your properties private and implement required methods from supertypes manually, for example:

data class User(
    private val username: String = ""
    ...
): UserDetails {
    override fun getUsername() = username
    ...
}

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