RowFilter.NumberFilter:无法处理“混合"；具体数字类型

Knowing that detail, the test failure is not astonishing (in hind-sight, would have never thought of that being an issue ;-) One level of defense is to make sure - in client code - that the numbers to compare are of the same class. That's not always possible (think f.i.: a tableColumn with columnClass Number) So I'm wondering if/how to improve on the fallback. Something like:

if (one instanceof Comparable && one.getClass() == other.getClass()) {
    // same class, use comparator
    return ((Comparable) one).compareTo(other);
}
if (areIntegers(one, other)) {
    // all integers, use longValue
    return longCompare(one, other);
}
if (areDecimals(one, other)) {
    // anything to do here?
}
// at last resort convert to BigDecimal and compare those: 
BigDecimal bigOne = new BigDecimal(one.toString());
BigDecimal bigOther = new BigDecimal(other.toString());
return bigOne.compareTo(bigOther);

Doing so, makes the test pass - I'm a bit wary about hidden (read: unknown to me :) pitfalls. Any warnings/alternatives highly welcome!

FYI: cross-posted to OTN's Swing forum

Follow-up

implemented as outlined above, now waiting for clients to complain - in that case will point fingers to everybody who didn't warn me here :-)

I don't have a better answer, but the example below illustrates the effect. In particular, a RowFilter based on a double primitive is boxed as Double, producing the expected tableau having values > 1. In contrast, the one based on a float is boxed as Float. Because the class literals do not match, include() compares the long values, unexpectedly filtering all fractional values < 2.

import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.event.ActionEvent;
import java.util.Arrays;
import javax.swing.AbstractAction;
import javax.swing.JFrame;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.JToggleButton;
import javax.swing.RowFilter;
import javax.swing.RowFilter.ComparisonType;
import javax.swing.table.AbstractTableModel;
import javax.swing.table.TableRowSorter;

/** @see http://stackoverflow.com/questions/7993546 */
public class FilterTest {

    private static TableRowSorter<TableModel> sorter;
    private static RowFilter<TableModel, Integer> dFilter;
    private static RowFilter<TableModel, Integer> fFilter;
    private static boolean b;

    public static void main(String[] args) {
        TableModel model = new TableModel();
        JTable table = new JTable(model);
        sorter = new TableRowSorter<TableModel>(model);
        dFilter = RowFilter.numberFilter(ComparisonType.AFTER, 1d, 0);
        fFilter = RowFilter.numberFilter(ComparisonType.AFTER, 1f, 0);
        sorter.setRowFilter(dFilter);
        table.setRowSorter(sorter);
        JScrollPane scrollPane = new JScrollPane(table);
        table.setPreferredScrollableViewportSize(new Dimension(320, 240));

        JFrame f = new JFrame("Test");
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        f.add(scrollPane, BorderLayout.CENTER);
        f.add(new JToggleButton(new AbstractAction("Toggle") {

            @Override
            public void actionPerformed(ActionEvent e) {
                b = !b;
                if (b) {
                    sorter.setRowFilter(fFilter);
                } else {
                    sorter.setRowFilter(dFilter);
                }
            }
        }), BorderLayout.SOUTH);

        f.pack();
        f.setVisible(true);
    }

    private static class TableModel extends AbstractTableModel {

        private static final int ROWS = 16;
        private static final int COLS = 4;
        private Double[][] matrix = new Double[ROWS][COLS];

        public TableModel() {
            double v = 0;
            for (Object[] row : matrix) {
                Arrays.fill(row, Double.valueOf(v += 0.25));
            }
        }

        @Override
        public int getRowCount() {
            return ROWS;
        }

        @Override
        public int getColumnCount() {
            return COLS;
        }

        @Override
        public Object getValueAt(int row, int col) {
            return matrix[row][col];
        }

        @Override
        public Class<?> getColumnClass(int col) {
            return Number.class;
        }
    }
}

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