在 Kotlin 中仅使用 getter 覆盖 Java 接口

Question

I have this interface in Java:

public interface ErrorInfo {
  String getCode();
  String getMessage();
}

And I want it to override in Kotlin code. I can't seem to do it.

Here's what I tried:

Here, I get an error that '<field> overrides nothing'

class ErrorInfoImpl(
  override val code: String,
  override val message: String
) : ErrorInfo

Here, I get the same error '<field> overrides nothing'

class ErrorInfoImpl(
  code: String,
  message: String
) : ErrorInfo {
   override val code: String = code
   override val message: String message
}

This code works, but it looks dirty:

class ErrorInfoImpl(
  private val __code: String,
  private val __message: String
) : ErrorInfo {
    override fun getCode(): String = __code
    override fun getMessage(): String = __message
}

Are there better ways to do this?

Answer 1

The contract is to have getCode() and getMessage() methods only. What it returns is up to implementing class. The cleanest in this case is following:

class ErrorInfoImpl(
  private val code: String,
  private val message: String
) : ErrorInfo {
    override fun getCode(): String = code
    override fun getMessage(): String = message
}