Limit the jtable cell values between 0 and 20 in java

Question

I want to program Java software which contains a jTable. In this jTable, there is a column (Double value). My problem is that I want to limit the "Double" value entered by the user between -1 and 20. Is there any solution? Thank you

Answer 1

You will need to create a custom editor.

Here is an example to get you started:

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.text.*;
import javax.swing.event.*;
import javax.swing.border.*;
import javax.swing.table.*;

public class TableEdit extends JFrame
{
    TableEdit()
    {
        JTable table = new JTable(5,5);
        table.setPreferredScrollableViewportSize(table.getPreferredSize());

        JScrollPane scrollpane = new JScrollPane(table);
        add(scrollpane);

        //  Use a custom editor

        TableCellEditor fce = new FiveCharacterEditor();
        table.setDefaultEditor(Object.class, fce);

        add(new JTextField(), BorderLayout.NORTH);
    }

    class FiveCharacterEditor extends DefaultCellEditor
    {
        private long lastTime = System.currentTimeMillis();

        FiveCharacterEditor()
        {
            super( new JTextField() );
        }

        public boolean stopCellEditing()
        {
            JTable table = (JTable)getComponent().getParent();

            try
            {
                String editingValue = (String)getCellEditorValue();
                System.out.println(table.isEditing());
                System.out.println(editingValue);

                if(editingValue.length() != 5)
                {
                    JTextField textField = (JTextField)getComponent();
                    textField.setBorder(new LineBorder(Color.red));
                    textField.selectAll();
                    textField.requestFocusInWindow();

                    JOptionPane.showMessageDialog(
                        null,
                        "Please enter string with 5 letters.",
                        "Alert!",JOptionPane.ERROR_MESSAGE);
                    return false;
                }
            }
            catch(ClassCastException exception)
            {
                return false;
            }

            return super.stopCellEditing();
        }

        public Component getTableCellEditorComponent(
            JTable table, Object value, boolean isSelected, int row, int column)
        {
            Component c = super.getTableCellEditorComponent(
                table, value, isSelected, row, column);
            ((JComponent)c).setBorder(new LineBorder(Color.black));

            return c;
        }

    }

    public static void main(String [] args)
    {
        JFrame frame = new TableEdit();
        frame.setDefaultCloseOperation(EXIT_ON_CLOSE);
        frame.pack();
        frame.setLocationRelativeTo( null );
        frame.setVisible(true);
    }
}