Java调用scala中map转换问题处理-Toy模板网

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网上代码把Javamap转为scala的map代码

    	scala.collection.mutable.Map<String, String> scalaMap = JavaConverters.mapAsScalaMapConverter(map).asScala();
        Object objMap = Map$.MODULE$.<String, String>newBuilder().$plus$plus$eq(scalaMap.toSeq());
        Object BuildResObjMap = ((scala.collection.mutable.Builder) objMap).result();
        scala.collection.immutable.Map<String, String> targetScalaMap = (scala.collection.immutable.Map) BuildResObjMap;
        return targetScalaMap;

我自身是用scala2.11.8, jdk8, 同样代码在本机报错如下:

Java调用scala中map转换问题处理

toSeq()方法就一个方法还会不明确也是奇葩, 遂去翻源码,然后发现seq和其他集和对象关系

Java调用scala中map转换问题处理

那么算了不去转到seq了, 我转到他的子类总改明确吧, 遂把代码改成以下两种方式分别实验:

  public static scala.collection.immutable.Map<String, String> javaMapConvertToScalaMap(Map<String, String> map) {
        scala.collection.mutable.Map<String, String> scalaMap = JavaConverters.mapAsScalaMapConverter(map).asScala();
        Object objMap = Map$.MODULE$.<String, String>newBuilder().$plus$plus$eq(scalaMap.toList());

        
        Object BuildResObjMap = ((scala.collection.mutable.Builder) objMap).result();
        scala.collection.immutable.Map<String, String> targetScalaMap = (scala.collection.immutable.Map) BuildResObjMap;
        return targetScalaMap;
    }

另外一种:

    public static scala.collection.immutable.Map<String, String> javaMapConvertToScalaMap(Map<String, String> map) {
        scala.collection.mutable.Map<String, String> scalaMap = JavaConverters.mapAsScalaMapConverter(map).asScala();
        Object objMap2 = Map$.MODULE$.<String, String>newBuilder().$plus$plus$eq(scalaMap.toIndexedSeq());

        
        Object BuildResObjMap = ((scala.collection.mutable.Builder) objMap).result();
        scala.collection.immutable.Map<String, String> targetScalaMap = (scala.collection.immutable.Map) BuildResObjMap;
        return targetScalaMap;
    }

最后终于能通过编译和运行, 终于开始开始调试spark了, nnd文章来源地址https://www.toymoban.com/news/detail-508436.html

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