how to align a column in DefaultTableCellRenderer with sqlite after concatenation

I am trying to align the values of a column (Grades). Which is formed as result of concatenation of the following columns

(AAA||BPLUS||BBB||CPLUS||CCC||DDD||EEE||FFF)

I want the values to be align in the middle or centre of the column...

This is what I have tried

try{
String sql = "select courseCode as CourseCode,courseName as CourseName,unit as Unit,total as Total,(AAA||BPLUS||BBB||CPLUS||CCC||DDD||EEE||FFF) as Grade,gpp as GradePoint,ugp as Product,Remarks as Remarks from ResultUpload where idNumber=? and level=? and semester=2";
              pst=conn.prepareStatement(sql);
              pst.setString(1,isearchTextField.getText());
              pst.setString(2,levelComboBox.getSelectedItem().toString());

              rs=pst.executeQuery();

               partITable2.setModel(DbUtils.resultSetToTableModel(rs)); 

               DefaultTableCellRenderer rightRenderer = new DefaultTableCellRenderer();
               rightRenderer.setHorizontalAlignment(DefaultTableCellRenderer.CENTER);
               partITable2.getColumn("Grade").setCellRenderer(rightRenderer);

          }
          catch(Exception ex){

          }
           finally{
        try{
            rs.close();
            pst.close();
        }
        catch(Exception e){
        }
        }