spark sql 之 collect_set collect_list 后WrappedArray 取值

示例：demo数据

userId	place
1001	北京
1001	上海

spark建立的虚拟表 userPlaceView。根据用户ID进行分组，用collect_set(place)获取place信息。
spark sql 函数查询 地址

Dataset<Row> resultDataSet = SqlContext.sql("select userId, collect_set(place) as place from userPlaceView group by userId");
resultDataSet.javaRDD().map((Function<Row, UserPlaces>) f->{ //获取分组聚合后的place信息
	//WrappedArray 开始
	WrappedArray wrappedArray = (WrappedArray)f.get(1);
	for(int i=0; i<wrappedArray.size(); i++){
         WrappedArray data = (WrappedArray)wrappedArray.apply(i);
         for(int z=0; z<data.size(); z++){
             String place = (String)data.apply(z);
             System.out.println(place);
         }
     }
     ......
});