一、前述
SparkStreaming中的算子分为两类,一类是Transformation类算子,一类是OutPutOperator类算子。
Transformation类算子updateStateByKey,reduceByKeyAndWindow,transform
OutPutOperator类算子print,foreachRDD,saveAsTextFile
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本文讲解OutPutOperator类算子。
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二、具体
1、foreachRDD
可以拿到DStream中的一个个的RDD,对拿到的RDD可以使用Transformation类算子对数据进行转换,foreachRDD方法内,拿到的RDD Transformation类算子外的代码是在Driver端执行