title: Easy way to get the data from selected columns in JTable
body: <p>I have a <code>JTable</code> and want to get the data from each selected column. The columns are selected by mouse clicks. So, if there are  5 columns selected, the output has to be 5 string arrays.</p>
  
  <p>I'm trying to do this by <code>MouseListener</code>, but I can get only the clicked cells, not the entire column. </p>