Centering text in a cell in a JTable

Question

Hi,
I have a program that reads in data from a text file and display it in a JTable. My problem is that the data in each cell is not centered, it is left justified within that cell.
How can I fix this.
--kirk                                                                                                                                                                                                                                                                                                                                                                                                                                            

Answer 1

To align a text inside a cell you have to go through the rendering classes of a Jtable. You can do lots of formatting by using a render class. Heres my code that i use.
1. The first code aligns your data centered inside the cell.
2. The second code aligns it like code1 but has an additional character to be printed beside your data inside the text.
///////////// TO USE THE RENDER CODE IN YOUR APPLICATION /////
TableColumn col1 = table.getColumnModel().getColumn(1);
col1.setCellRenderer( new SimpleRenderer());
or
TableColumn col1 = table.getColumnModel().getColumn(1);
col1.setCellRenderer( new SimpleRenderer( "$" ));
///////////// RENDER CODE IS HERE //////////////
import javax.swing.table.*;
import javax.swing.border.*;
import javax.swing.*;
import java.awt.*;
public class SimpleRenderer extends JLabel implements TableCellRenderer
     Border unselectedBorder = null;
     Border selectedBorder = null;
     String text = "";
     Color foreColor = Color.black;
     Color backColor = new java.awt.Color( 217,217,255 );
     Color selectedColor = new java.awt.Color( 217,217,255 );
     public SimpleRenderer()
     super();
     setHorizontalAlignment( JLabel.CENTER );
     setOpaque( true );
     } // end of CONSTRUCTOR
     public SimpleRenderer( Color foreGround, Color backGround )
     super();
     setHorizontalAlignment( JLabel.CENTER );
     setOpaque( true );
     this.foreColor = foreGround;
     this.backColor = backGround;
     } // end of CONSTRUCTOR
     public SimpleRenderer( String data )
     super();
     text = data;
     setHorizontalAlignment( JLabel.CENTER );
     setOpaque( true );
     } // end of CONSTRUCTOR
     public Component getTableCellRendererComponent(
          JTable table, Object object, boolean isSelected, boolean hasFocus,
                                                                                int row, int column)
     try
          if ( backColor != null )
               if ( (row % 2 ) == 1 )
                         setBackground( backColor );
               else
                         setBackground( Color.white );
          if ( foreColor != null )
               setForeground( foreColor );
          if ( hasFocus )
               if ( isSelected )
                         setBackground( selectedColor );
               else
                         setBackground( Color.white );
          String newData = "" + object;
          if ( newData.trim().equals( "" ))
               setText( "" );
          else
               setText( text + " " + object );
          if (isSelected)
          if (selectedBorder == null)
               Border border, raisedBevel, loweredBevel;
               raisedBevel = BorderFactory.createRaisedBevelBorder();
               loweredBevel = BorderFactory.createLoweredBevelBorder();
               Border colorLine = BorderFactory.createLineBorder(Color.red);
               border = BorderFactory.createCompoundBorder( raisedBevel,loweredBevel);
               selectedBorder = BorderFactory.createCompoundBorder( border, colorLine);
          setBorder(selectedBorder);
          else
          if (unselectedBorder == null)
                    unselectedBorder = BorderFactory.createMatteBorder(0,0,0,0,
                    table.getBackground());
          setBorder(unselectedBorder);
     catch( ClassCastException e )
     return this;
     } // end of GETTABLECELLRENDERERCOMPONENT method.
     public void setForeColor( Color data )
     foreColor = data;
     } // end of SETFORECOLOR method.
     public void setBackColor( Color data )
     backColor = data;
     } // end of SETBACKCOLOR method.
} /** end of CLASS **/
/////////////