Java sample(Edit table Display)

//Example1b.java
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Component;
import java.awt.Dimension;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.SwingConstants;
import javax.swing.table.DefaultTableCellRenderer;
import javax.swing.table.TableColumn;
public class Example1b {
  private static final String window_title = "Edit table display";
  private static final int locate_X = 50;
  private static final int locate_Y = 50;
  private static final int window_width = 320;
  private static final int window_height = 160;
  private static final int table_width = 300;
  private static final int table_height = 120;
  private static final int table_row_height = 20;
  // data
  Object[] colNames = { "name", "amount", "size", "color", "note" };
  Object[][] rowData = { { "A01", "20", "large", "white", "soft" },
      { "K01", "5", "thin", "red", "strong" },
      { "U01", "100", "middle", "yellow", "cheap" },
      { "S01", "2.5", "middle", "black", "quality" }, };
  // main
  public static void main(final String args[]) {
    final Example1b sample = new Example1b();
  }
  // constructor
  public Example1b() {
    final JFrame f = new JFrame(Example1b.window_title);
    f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    final JTable t = new JTable(this.rowData, this.colNames);
    t.setRowHeight(Example1b.table_row_height);
    t.setGridColor(Color.gray);
    for (int i = 0; i < t.getColumnCount(); ++i) {
      final TableColumn tc = t.getColumn(t.getColumnName(i));
      tc.setCellRenderer(new MyRenderer());
    }
    final JScrollPane sp = new JScrollPane();
    sp.getViewport().setView(t);
    sp.setPreferredSize(new Dimension(Example1b.table_width,
        Example1b.table_height));
    final JPanel p = new JPanel();
    p.add(sp);
    f.getContentPane().add(p, BorderLayout.CENTER);
    f.setBounds(Example1b.locate_X, Example1b.locate_Y,
        Example1b.window_width, Example1b.window_height);
    f.setVisible(true);
  }
  // CellRenderer
  class MyRenderer extends DefaultTableCellRenderer {
    private static final long serialVersionUID = 1L;
    @Override
    public Component getTableCellRendererComponent(final JTable table,
        final Object value, final boolean isSelected,
        final boolean hasFocus, final int row, final int column) {
      switch (column) {
      case 1:
        this.setHorizontalAlignment(SwingConstants.RIGHT);
        break;
      case 2:
        this.setHorizontalAlignment(SwingConstants.CENTER);
        break;
      case 3:
        this.setHorizontalAlignment(SwingConstants.CENTER);
        switch (row) {
        case 0:
          this.setBackground(Color.black);
          this.setForeground(Color.white);
          break;
        default:
          this.setBackground(Color.yellow);
          this.setForeground(Color.red);
          break;
        }
      default:
        break;
      }
      return super.getTableCellRendererComponent(table, value,
          isSelected, hasFocus, row, column);
    }
  }
}