星火：JavaRDD＆LT; Tuple2＆GT;到JavaPairRDD＆LT;＆GT;
问题描述：
我有一个 JavaRDD＆LT; Tuple2＆LT;字符串，字符串＆GT;＆GT; ，并需要将其转换为 JavaPairRDD＆LT;字符串，字符串＆GT; 。目前，我只需编写map函数，仅仅返回输入元组的是这样做。但我不知道是否有更好的办法？
I have a JavaRDD<Tuple2<String, String>> and need to transform it to JavaPairRDD<String, String>. Currently I am doing it by simply writing map function that just returns the input tuple as is. But I wonder if there is a better way?
答
JavaPairRDD.fromJavaRDD（RDD）是解决方案之一
JavaPairRDD.fromJavaRDD(rdd) is one of solutions