如何將嵌套的複雜Scala地圖轉換爲Java

Question

我想在我的Java程序中使用Scala庫，並且將複雜的Scala地圖轉換爲Java有一些困難。

我使用Scala的對象方法有以下返回類型：scala.collection.mutable.Map<String, Map<Object, Seq<Object>>>

如何將其轉換成一個相當於Java的Map<String, Map<Object, List<Object>>>？

我已經與JavaConversions和JavaConvertors包，但沒有運氣:(發揮各地

public void getPartitionAssignmentForTopics(final List<String> topics) { 
    final Seq<String> seqTopics =   scala.collection.JavaConversions.asScalaBuffer(topics).toList(); 
    scala.collection.mutable.Map<String, Map<Object, Seq<Object>>> map2 = zkUtils 
      .getPartitionAssignmentForTopics(seqTopics); 

    val map:scala.collection.mutable.Map[String, Map[Object, Seq[Object]]] = scala.collection.mutable.Map() 
    map: 
    collection.mutable.Map[String, Map[Object, Seq[Object]]] =Map() 
    map.mapValues(_.mapValues(_.asJava).asJava).asJava 
    res2: 
    java.util.Map[String, java.util.Map[Object, java.util.List[Object]]] ={} 
} 

這並不編譯:)

隨着玩弄我的意思是，我使用下面的代碼要轉換Scala Seq到Java列表： scala.collection.JavaConversions.seqAsJavaList(zkUtils.getAllTopics());

Answer 1

我結束了以下代碼。不是很好：D

public java.util.Map<String, java.util.Map<Integer, java.util.List<Integer>>> getPartitionAssignmentForTopics(final List<String> topics) { 
    final scala.collection.Seq<String> seqTopics = scala.collection.JavaConversions.asScalaBuffer(topics).toList(); 
    scala.collection.mutable.Map<String, scala.collection.Map<Object, scala.collection.Seq<Object>>> tmpMap1 = 
      zkUtils.getPartitionAssignmentForTopics(seqTopics); 

    final java.util.Map<String, java.util.Map<Integer, java.util.List<Integer>>> result = new HashMap<>(); 
    java.util.Map<String, Map<Object, Seq<Object>>> tmpMap2 = JavaConversions.mapAsJavaMap(tmpMap1); 
    tmpMap2.forEach((k1, v1) -> { 
     String topic = (String)k1; 
     java.util.Map<Object, Seq<Object>> objectSeqMap = JavaConversions.mapAsJavaMap(v1); 
     java.util.Map<Integer, List<Integer>> tmpResultMap = new HashMap<>(); 
     objectSeqMap.forEach((k2, v2) -> { 
      Integer tmpInt = (Integer)k2; 
      List<Integer> tmpList = (List<Integer>)(Object)JavaConversions.seqAsJavaList(v2); 
      tmpResultMap.put(tmpInt, tmpList); 
     }); 
     result.put(topic, tmpResultMap); 
    }); 

    return result; 
}