用JavaConverters替换JavaConversions

Question

当我尝试运行基于this example的代码时，我收到以下警告：

warning: object JavaConversions in package collection is deprecated (since 2.12.0): use JavaConverters

AFAICT，负责警告的行是：

import scala.collection.JavaConversions._

/* ... */

    for ((k,v) <- environmentVars) println(s"key: $k, value: $v")

用

替换import行

import scala.collection.JavaConverters._

......还不够;单独这样做会导致错误：

error: value withFilter is not a member of java.util.Map[String,String]
    for ((k,v) <- environmentVars) println(s"key: $k, value: $v")

还有什么必须做的？

Answer 1

您需要添加asScala方法：

import scala.collection.JavaConverters._

for ((k,v) <- environmentVars.asScala) println(s"key: $k, value: $v")

Answer 2

仅供参考，scala.collection.JavaConverters已替换为scala.jdk.CollectionConverters