java自己绘制多层表头

import java.awt.Dimension;
import java.awt.Graphics;

import javax.swing.JComponent;
import javax.swing.JLabel;
import javax.swing.UIManager;
import javax.swing.plaf.basic.BasicTableHeaderUI;
import javax.swing.table.JTableHeader;

import org.jdesktop.swingx.JXTable;

public class MappingTableHeaderUI extends BasicTableHeaderUI {

  private JTableHeader header;
  private MappingTableModel tableModel;
  private JXTable mappingTable;
   public MappingTableHeaderUI(JXTable table){
    this.tableModel =(MappingTableModel) table.getModel();
    mappingTable = table;
    mappingTable.getTableHeader().setPreferredSize(new Dimension(10000, 30));

   }

  public void paint(Graphics g, JComponent c) {  

   header = (JTableHeader) c;
   JLabel label=getLabel("");
   for (int i = 0; i< tableModel.getSingleColumnCount(); i++){
    String columnName = tableModel.getColumnName(i);
    label = getLabel(columnName);
    rendererPane.paintComponent(g, label, header, getX(i), 0, getWidth(i), 30, true);
   }
   for(int j = 0 ;j < tableModel.getGroupColumnCounts(); j++){
    String groupcolumnName = tableModel.getGroupColumnName(j);
    label = getLabel(groupcolumnName);
    int groupwidth = 0;
    for(int k = 0 ;k < tableModel.getGroupColumnSubCounts(j) ; k++){
     int index = tableModel.changeToTotalColumnIndex(j,k);
     String columnName = tableModel.getColumnName(index);
     label = getLabel(columnName);
     rendererPane.paintComponent(g, label, header, getX(index), 15, getWidth(index), 15, true);
     groupwidth +=getWidth(index);
    }
    int groupindex = tableModel.changeToTotalColumnIndex(j,0);
    rendererPane.paintComponent(g, label, header, getX(groupindex), 0, groupwidth, 15, true);
   }
  

  }

  private int getX(int column){

   int x=0;

     for(int i=0;i<column;i++){
//      if(i < tableModel.getSingleColumnCount()){
//       x+=tableModel.getSingleColumnWidth(i);
//      }else{
       x+=header.getColumnModel().getColumn(i).getWidth();
//      }
     }

     

     return x;

   }
 
  private int getWidth(int column){
//   if(column < tableModel.getSingleColumnCount()){
//    return tableModel.getSingleColumnWidth(column);
//   }

    return header.getColumnModel().getColumn(column).getWidth();

   }

 

  private JLabel getLabel(String text){

   JLabel label = new JLabel(text, JLabel.CENTER);

   label.setBorder(UIManager.getBorder("TableHeader.cellBorder"));

   return label;

  }

 }