JTable how can i show numbers as (#.00) format in double column class?

Question

My JTable model

DefaultTableModel modelim = new DefaultTableModel() {
            public Class getColumnClass(int column) {
                switch (column) {
                    case 0:
                        return Integer.class;
                    case 1:
                        return String.class;
                    case 2:
                        return String.class;
                    case 3:
                        return String.class;
                    case 4:
                        return Date.class;
                    case 5:
                        return Double.class;
                    default:
                        return String.class;
                }
            }
        };

I have a JTable. Column 5 is for double numbers. For example.

1234.25
177.12
1745.02
1748.10
1899.00

This is the items of column 5. But when i start the program they look like this.

1234.25
177.12
1745.02
1748.1 //different
1899.0 //different

So it shows atleast 1 number after the dot. But i want to see the number with 2 nubmers after the dot.

1748.10
1899.00

As this. I can share more code if you guys need.

Answer 1

Use a custom cell renderer. See How to Use Tables and Using Custom Renderers

import java.awt.BorderLayout;
import java.awt.Component;
import java.awt.EventQueue;
import java.text.NumberFormat;
import java.util.Date;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.table.DefaultTableCellRenderer;
import javax.swing.table.DefaultTableModel;

public class Test {

    public static void main(String[] args) {
        new Test();
    }

    public Test() {
        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                JFrame frame = new JFrame();
                frame.add(new TestPane());
                frame.pack();
                frame.setLocationRelativeTo(null);
                frame.setVisible(true);
            }
        });
    }

    public class TestPane extends JPanel {

        public TestPane() {
            setLayout(new BorderLayout());
            JTable table = new JTable();
            DefaultTableModel modelim = new DefaultTableModel() {
                public Class getColumnClass(int column) {
                    switch (column) {
                        case 0:
                            return Integer.class;
                        case 1:
                            return String.class;
                        case 2:
                            return String.class;
                        case 3:
                            return String.class;
                        case 4:
                            return Date.class;
                        case 5:
                            return Double.class;
                        default:
                            return String.class;
                    }
                }

                @Override
                public int getColumnCount() {
                    return 6;
                }
            };

            modelim.addRow(new Object[] {1, "1", "1", "1", new Date(), 1.234567});
            modelim.addRow(new Object[] {1, "1", "1", "1", new Date(), 2.345678});
            modelim.addRow(new Object[] {1, "1", "1", "1", new Date(), 3.456789});
            modelim.addRow(new Object[] {1, "1", "1", "1", new Date(), 4.567890});
            modelim.addRow(new Object[] {1, "1", "1", "1", new Date(), 5.678901});
            modelim.addRow(new Object[] {1, "1", "1", "1", new Date(), 6.789012});

            table.setAutoCreateRowSorter(true);
            table.setModel(modelim);
            table.getColumnModel().getColumn(5).setCellRenderer(new DoubleFormatTableCellRenderer());

            add(new JScrollPane(table));
        }

    }

    public class DoubleFormatTableCellRenderer extends DefaultTableCellRenderer {

        private NumberFormat numberFormat;

        public NumberFormat getNumberFormat() {
            if (numberFormat == null) {
                numberFormat = NumberFormat.getNumberInstance();
                numberFormat.setMinimumFractionDigits(2);
                numberFormat.setMaximumFractionDigits(2);
            }
            return numberFormat;
        }

        @Override
        public Component getTableCellRendererComponent(JTable table, Object value, boolean isSelected, boolean hasFocus, int row, int column) {
            if (value instanceof Double) {
                value = getNumberFormat().format(value);
            } 

            return super.getTableCellRendererComponent(table, value, isSelected, hasFocus, row, column);
        }

    }
}

i do use one. It was ok but when i try to sort the numbers i does not sort right. So i hade to use Double column class to make them sort right. But after i use Double column class the numbers became as this

Next time, provide a minimal reproducible example - it will prevent use from running over ground you might have already gone and/or see why your solution didn't work