JTable How to align the Text in a Cell to Centre

Question

Hi Plese Help regarding JTable.
I want to align the Text in the Table Cell to Centre how to align it. Im using Abstract Data Model TAble an what is the meaning of renderer and its use.. Help me out

Answer 1

Here are a couple of links you should read for information on tables and renderers:
http://java.sun.com/docs/books/tutorial/uiswing/components/table.html#editrender
http://www-106.ibm.com/developerworks/java/library/j-jtable/index.html?dwzone=java
Here is an example of a simple renderer that will:
a) center the text
b) highlight the background when the cell gets focus
This renderer is only used in two of the columns of the table.
import java.awt.*;
import java.util.*;
import javax.swing.*;
import javax.swing.table.*;
public class TableRenderer extends JFrame
     public TableRenderer()
          String[] columnNames = {"Date", "String", "Integer1", "Integer2", "Boolean"};
          Object[][] data =
               {new Date(), "A", new Integer(1), new Integer(5), new Boolean(true)},
               {new Date(), "B", new Integer(2), new Integer(6), new Boolean(false)},
               {new Date(), "C", new Integer(3), new Integer(7), new Boolean(true)},
               {new Date(), "D", new Integer(4), new Integer(8), 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 and highlight the focused cell
     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);
               if (hasFocus)
                    setBackground( Color.cyan );
               else if (isSelected)
                    setBackground( table.getSelectionBackground() );
               else
                    setBackground( table.getBackground() );
               return this;