Scala-Java interop-是否可以從scala中“選擇”被調用的java方法？

Question

我在Scala代碼（scala 2.10.4）中調用Jedis（Java）時遇到一些互操作性問題。

我有一個在隱式類中實現的特征

在基礎類上調用方法時出現以下錯誤

implicit class Redis(private val underlying: Jedis) extends com.dy.storage.Redis {
    override def del(keys: String*): Long = {
      underlying.del(keys: _*)
    }

    override def del2(keys: Seq[Array[Byte]]): Long = {
      underlying.del(keys: _*)
    }
}

收到以下錯誤（ scala 2.10.4 ）：

no `: _*' annotation allowed here
[error] (such annotations are only allowed in arguments to *-parameters)
[error]       underlying.del(keys: _*)
[error]                          ^
[error] /Users/avnerbarr/workspace/redis-hashed-no `: _*' annotation allowed here
[error] (such annotations are only allowed in arguments to *-parameters)
[error]       underlying.del(keys: _*)
[error]                          ^

我試圖添加一個包裝器並將有問題的調用移到隱式類之外：

    override def del(keys: String*): Long = {
      Wrapper.delete(underlying, keys)
    }


object Wrapper {
  def delete(u : Jedis, str: Seq[String]): Long = {
    u.del(str:_*)
  }
}

然后出現此錯誤：

overloaded method value del with alternatives:
[error]   (x$1: String)Long <and>
[error]   (x$1: <repeated...>[String])Long <and>
[error]   (x$1: Array[Byte])Long <and>
[error]   (x$1: <repeated...>[Array[Byte]])Long
[error]  cannot be applied to (Char)
[error]     u.del(a:_*)
[error]       ^
[info] Checking every *.class/*.jar file's SHA-1.
[error] one error found

使用scala 2.11時，此代碼構建完全沒有問題，僅在scala 2.10中解決了該問題

是否可以“選擇”而不推論應該調用的正確方法？

Answer 1

您應該提供Jedis和com.dy.storage.Redis代碼。

以下代碼編譯：

src / main / java / Jedis.java

interface Jedis {
  long del(String... keys);
  long del(byte[]... keys);
}

src / main / scala / com / dy / storage / Redis.scala

package com.dy.storage

trait Redis {
  def del(keys: String*): Long
  def del2(keys: Seq[Array[Byte]]): Long
}

src / main / scala / App.scala

object App {
  implicit class Redis(private val underlying: Jedis) extends com.dy.storage.Redis {
    override def del(keys: String*): Long = {
      underlying.del(keys: _*)
    }

    override def del2(keys: Seq[Array[Byte]]): Long = {
      underlying.del(keys: _*)
    }
  }
}

build.sbt

name := "scala2104"
version := "0.1"
scalaVersion := "2.10.4"