Converting a Spark Dataframe to a Scala Map collection
<p>I'm trying to find the best solution to convert an entire Spark dataframe to a scala Map collection. It is best illustrated as follows:</p>

<p>To go from this (in the Spark examples):</p>

<pre><code>val df = sqlContext.read.json("examples/src/main/resources/people.json")

df.show
+----+-------+
| age|   name|
+----+-------+
|null|Michael|
|  30|   Andy|
|  19| Justin|
+----+-------+
</code></pre>

<p>To a Scala collection (Map of Maps) represented like this:</p>

<pre><code>val people = Map(
Map("age" -&gt; null, "name" -&gt; "Michael"),
Map("age" -&gt; 30, "name" -&gt; "Andy"),
Map("age" -&gt; 19, "name" -&gt; "Justin")
)
</code></pre>