13.foreach(func) 遍历RDD中每一个元素12.saveAsObjectFile(path)序列化成对象保存到文件11.saveAsSequenceFile(path)保存成Sequencefile文件10.saveAsTextFile(path)保存成Text文件09.countByKey()统计每种key的个数08.fold07.aggregate06.takeOrdered(n, [ordering])返回该RDD排序后前n个元素组成的数组05.first04.take(n)03.count()02.collect01.reduce(func)概述