title: Inserting integer (not String) data into a JavaFX2 TableView
body: <p>so I've got a table working properly and grabbing data from an <code>ObservableList</code> with the code here:</p>
  
  <pre><code>public void setMainTableData(ObservableList&lt;FileMP3&gt; list)
      {
          artistCol.setCellValueFactory(new PropertyValueFactory&lt;FileMP3, String&gt;("artist"));
          albumCol.setCellValueFactory(new PropertyValueFactory&lt;FileMP3, String&gt;("album"));
          titleCol.setCellValueFactory(new PropertyValueFactory&lt;FileMP3, String&gt;("title"));
          trackCol.setCellValueFactory(new PropertyValueFactory&lt;FileMP3, String&gt;("track"));
          yearCol.setCellValueFactory(new PropertyValueFactory&lt;FileMP3, String&gt;("year"));
          mainTable.setItems(list);
      }   
  </code></pre>
  
  <p>These columns, however do not ALL contain string data - I need to able to insert an <code>int</code>, and potentially other types like <code>Duration</code>. The <code>track</code> and <code>year</code> entries are stored as integers, and there is a (not shown) entry called <code>length</code>. This is stored in my <code>FileMP3</code> object as a <code>Duration</code>, and I don't see any obvious way to manipulate the data stored there before inserting it into the table. I'd like to be able to use <code>Duration.getMillis()</code> and then perform some math on that to get it into a displayable <code>int</code> format, but I want to keep it stored in the <code>FileMP3</code> as <code>Duration</code>.</p>
  
  <p>All the tutorials I've read on the topic all use the constructor as such:</p>
  
  <p><code>new PropertyValueFactory&lt;FileMP3, String&gt;("genre")</code></p>
  
  <p>All in all, I'd like to be able to insert something other than a <code>String</code> into the table.</p>