Centering text in JTable cells

Question

How do I center the text in JTable cells? By default, all data is left aligned.
Thanks,
Jason

Answer 1

Read up on cell renderers from the Swing tutorial on "Using Tables":
http://java.sun.com/docs/books/tutorial/uiswing/components/table.html#editrender
Here's an example to get you started.
import java.awt.*;
import java.util.*;
import javax.swing.*;
import javax.swing.table.*;
import java.text.*;
public class TableRenderer extends JFrame
    public TableRenderer()
        String[] columnNames = {"Date", "String", "Integer", "Decimal", "Boolean"};
        Object[][] data =
            {new Date(), "A", new Integer(1), new Double(5.1), new Boolean(true)},
            {new Date(), "B", new Integer(2), new Double(6.2), new Boolean(false)},
            {new Date(), "C", new Integer(3), new Double(7.3), new Boolean(true)},
            {new Date(), "D", new Integer(4), new Double(8.4), new Boolean(false)}
        DefaultTableModel model = new DefaultTableModel(data, columnNames);
        JTable table = new JTable( model )
            //  Returning the Class of each column will allow different
            //  renderers to be used based on Class
            public Class getColumnClass(int column)
                return getValueAt(0, column).getClass();
        JScrollPane scrollPane = new JScrollPane( table );
        getContentPane().add( scrollPane );
        //  Create cell renderer
        TableCellRenderer centerRenderer = new CenterRenderer();
        //  Use renderer on a specific column
        TableColumn column = table.getColumnModel().getColumn(3);
        column.setCellRenderer( centerRenderer );
        //  Use renderer on a specific Class
        table.setDefaultRenderer(String.class, centerRenderer);
    public static void main(String[] args)
        TableRenderer frame = new TableRenderer();
        frame.setDefaultCloseOperation( EXIT_ON_CLOSE );
        frame.pack();
        frame.setVisible(true);
    **  Center the text
    class CenterRenderer extends DefaultTableCellRenderer
        public CenterRenderer()
            setHorizontalAlignment( CENTER );
        public Component getTableCellRendererComponent(
            JTable table, Object value, boolean isSelected, boolean hasFocus, int row, int column)
            super.getTableCellRendererComponent(table, value, isSelected, hasFocus, row, column);
            return this;