title: Error in creating ExpandableListView with HashMap<String,List<String>>
body: <p>I am trying to create one simple ExpandableListView in android application.</p>
  
  <p>Here is code that prepares data for ExpandableListView.I used for loop here because in my application this data is coming at run time so i am unable to recognize how long it will be.</p>
  
  <pre><code>header = new ArrayList&lt;String&gt;();
  child = new HashMap&lt;String, List&lt;String&gt;&gt;();
  
  header.add("Top 250");
  header.add("Now Showing");
  header.add("Coming Soon");
  
  for (int i = 0; i &lt; 3; i++) {
          List&lt;String&gt; Map = new ArrayList&lt;String&gt;();
          Map.add("Hello:" + i);
          child.put(header.get(i), Map);
  }
  </code></pre>
  
  <p>And to fill the ExpandableListView i created custom adapter here is the code.</p>
  
  <pre><code>@Override
  public Object getChild(int groupPosition, int childPosition) {
  
      String headerData = this._listDataHeader.get(groupPosition);
  
      List&lt;String&gt; listData = this._listDataChild.get(headerData);
  
      return listData.get(childPosition);
  
  }
  </code></pre>
  
  <p>when i am trying to run this app Header in the ExpandableListView appears perfect but when i click on particular header the application fails.</p>
  
  <p>here is the logcat.</p>
  
  <pre><code>java.lang.IndexOutOfBoundsException: Invalid index 1, size is 1
  
  at java.util.ArrayList.throwIndexOutOfBoundsException(ArrayList.java:251)
  
  at java.util.ArrayList.get(ArrayList.java:304)
  
  com.kamani.expandablelistdemo.MyCustomAdpater.getChild(MyCustomAdpater.java:36)
  
  com.kamani.expandablelistdemo.MyCustomAdpater.getChildView(MyCustomAdpater.java:51)
  
  android.widget.ExpandableListConnector.getView(ExpandableListConnector.java:451)
  </code></pre>
  
  <p><strong>I know that i am getting error in getChild() method in returning data it says IndexOutOfBoundsException but unable to understand how to make it correct so that it display one one Sting in one Header?</strong></p>