 <p>as far as I can see you have a custom <em>comparator</em> (why does that keep a reference to the sorter? looks fishy) not a custom RowSorter. </p> <p>The intended way to change sorting is to invoke toggleSortOrder(column) on RowSorter. For more fine-grained control you can need access to the DefaultRowSorter, f.i. its setSortKeys method. </p>