How to determine in Android how to get if statement working using ListView,Hashmap, & item.get(...)?

I am somewhat of a beginner to Android (somewhat), and I am having a problem adapting code to my use. I've gotten everything except the if statement. Which is sad, because that's a rather basic thing.

I'm parsing a JSON file, and outputting it's results into a ListView using a Hashmap. So far, so good. I want to put an AlertDialog as one of the String "put"s of the Hashmap. Fine.

However, I now want to check that if the title (which is in the map) ends in ".pdf", to do a different action rather than displaying the AlertDialog.

Code:

public void onItemClick(AdapterView<?> parent, View view, int position, long id) { HashMap<String, String> item = (HashMap<String, String>)     
parent.getItemAtPosition(position);
String theTitle = item.get("title");
String theDesc = item.get("description");
String theLink = item.get("link");
if (???condition???) {
      //code I already have
} else {
    final AlertDialog.Builder hope = new AlertDialog.Builder(MainActivity.this);
    hope.setTitle("Description");
    hope.setMessage(theDesc);
    hope.setPositiveButton("DISMISS",new DialogInterface.OnClickListener() {
        @Override
        public void onClick(DialogInterface dialog, int which) {
            dialog.dismiss();
            }});

    hope.setNegativeButton("",new DialogInterface.OnClickListener() {
        @Override
         public void onClick(DialogInterface dialog, int which) {
            dialog.dismiss();
        }});
    hope.show();
}

Any, and all, help would be most appreciated!