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当某个特质被用于组合类时，被称为混入。abstract class A { val message: String}class B extends A { val message = "I'm an instance of class B"}trait C extends A { def loudMessage = message.toUpperCase()}clas...

class StringIterator(s: String) extends AbsIterator { type T = Char private var i = 0 def hasNext = i < s.length def next() = { val ch = s charAt i i += 1 ch } object Stri...

mysparkTest2 my = new mysparkTest2();SparkSession spark = SparkSession. builder(). master( "local" ). appName( "mytest" ).getOrCreate();Dataset<String> logData = spar...

var spark = SparkSession.builder.master("local").appName("mytest").getOrCreate()//dataset -> rddvar dataset = spark.read.textFile("./test").cachevar result = dataset.rdd.map((a: String) => a...