Javafx: Re-sorting a column in a TableView

Question

I have a TableView associated to a TreeView. Each time a node in the TreeView is selected, the TableView is refreshed with different data.

I am able to sort any col

Answer 1

Marco Jakob's answer is good for most cases, but I found that I needed to create a comparator that matches the table sort order for more flexibility. You can then use any method that takes a comparator to do sorting, searching, etc. To create the comparator, I extended that ComparatorChain class from apache's Common-Collections to easily do multiple column sorting. It looks like this.

public class TableColumnListComparator extends ComparatorChain {
    public TableColumnListComparator(ObservableList columns) {
        // Get list of comparators from column list.
        for (TableColumn column : columns) {
            addComparator(new ColumnComparator(column));
        }
    }

    /**
     * Compares two items in a table column as if they were being sorted in the TableView.
     */
    private static class ColumnComparator implements Comparator {

        private final TableColumn column;

        /**
         * Default Constructor.  Creates comparator based off given table column sort order.
         *
         * @param column
         */
        public ColumnComparator(TableColumn column) {
            this.column = column;
        }

        @Override
        public int compare(Object o1, Object o2) {
            // Could not find a way to do this without casts unfortunately
            // Get the value of the column using the column's cell value factory.
            final ObservableValue obj1 = (ObservableValue) column.getCellValueFactory().call(
                    new TableColumn.CellDataFeatures(column.getTableView(), column, o1));
            final ObservableValue obj2 = (ObservableValue) column.getCellValueFactory().call(
                    new TableColumn.CellDataFeatures(column.getTableView(), column, o2));
            // Compare the column values using the column's given comparator.
            final int compare = column.getComparator().compare(obj1.getValue(), obj2.getValue());
            // Sort by proper ascending or descending.
            return column.getSortType() == TableColumn.SortType.ASCENDING ? compare : -compare;
        }
    }
}

You can then sort at anytime with

Collections.sort(backingList, new TalbeColumnListComparator(table.getSortOrder());

I use this to sort multiple lists with the same sort, sort on background threads, do efficient updates without resorting the whole list, etc. I think there are going to be some improvements to table sorting in Javafx 8 so this won't be necessary in the future.