zoukankan      html  css  js  c++  java
  • scala集合和Java集合对应转换操作

    用Scala编码的时候,经常会遇到scala集合和Java集合互相转换的case,

    scala.collection.Iterable <=> java.lang.Iterable

    scala.collection.Iterable <=> java.util.Collection

    scala.collection.Iterator <=> java.util.{ Iterator, Enumeration }

    scala.collection.mutable.Buffer <=> java.util.List

    scala.collection.mutable.Set <=> java.util.Set

    scala.collection.mutable.Map <=> java.util.{ Map, Dictionary }

    scala.collection.mutable.ConcurrentMap <=> java.util.concurrent.ConcurrentMap

    scala.collection.Seq  => java.util.List

    scala.collection.mutable.Seq => java.util.List

    scala.collection.Set  => java.util.Set

    scala.collection.Map => java.util.Map

    java.util.Properties => scala.collection.mutable.Map[String, String] 

    比如把Java的list快速转为scala的list

    import scala.collection.JavaConversions

    val scalaList = JavaConversions.asScalaBuffer(javaList).toList

    把scala的Map转换成java.util.Map

    import scala.collection.JavaConverters._
    val act_max:Map[String,String] = Map("time"->"100","favorite"->"1")
    val actionTime_maxs:java.util.Map[String, String] = act_max.asJava
  • 相关阅读:
    volatile关键字,使一个变量在多个线程间可见。
    grep sed awk
    mysql高级聚合
    Hive高级聚合GROUPING SETS,ROLLUP以及CUBE
    用SecureCRT来上传和下载文件
    mysql导出导入数据
    redis入门
    spark 常用技巧总结2
    生成数据库字典
    spark 常用技巧总结
  • 原文地址:https://www.cnblogs.com/xl717/p/11636882.html
Copyright © 2011-2022 走看看