how to construct an instance of BasicTableModelWrap to render a Tableview

[王文楠 <wq...@gmail.com>]

I get resultset base on JdbcTemplate  in spring

here is my sourcecode
////////////////////////////////////////////////////////////////////////////////////////////////////////////
public class JdbcPageTableModel implements IBasicTableModel {
..........
    public Iterator getCurrentPageRows(int nFirst, int nPageSize,
ITableColumn arg2,
            boolean arg3) {
        List list = new JdbcTemplate(dataSource).queryForList("select
login_name,password from user_info ");
        for(int i=0;i<list.size();i++){
            Map map = (Map)list.get(i);
            System.out.println("============"+map.get("login_name"));
        }
        return list.iterator();
    }
....................

}
public abstract class StockDetail extends BasePage{
................................
    public ITableModel getMyTableModel(){
        Object[] columns =
        {
        "user_name","user name","user_name",new Boolean(false)
        ,"password","password","password",new Boolean(false)
        };
        ExpressionTableColumnModel columnModel = new
ExpressionTableColumnModel(columns,new ExpressionEvaluatorImpl());
            return new
BasicTableModelWrap(getJdbcPageTableModel(),columnModel);
        }
...........................................
}

StockDetail.html
  <span jwcid="tableView@Contrib:TableView"
             tableModel="ognl:myTableModel"
              pageSize="ognl:10">
      <table width="800" border="1">
        <tr>
          <td height="24" bgcolor="#FCA632" align="center"
jwcid="@Contrib:TableColumns"></td>
        </tr>
        <tr jwcid="tableRows@Contrib:TableRows">
          <td bgcolor="#FFF1E1" height="24" align="center"
jwcid="@Contrib:TableValues">&nbsp;</td>
        </tr>
      </table>
     <table width ="100%"><tr><td align="center">
         <span jwcid="@Contrib:TableFormPages" pagesDisplayed="ognl:10"/>
    </td></tr></table>
</span>

///////////////////////////////////////////////////////////////////////////////////
the system can print out
"=============Green"
"==============John"
but the page StockDetail just display the title row of the table and other
rows with no content


the system print errors like this:
ERROR org.apache.tapestry.contrib.table.model.ognl.OgnlTableColumnEvaluator
- Cannot use column expression 'password' in row
java.lang.NullPointerException
    at org.apache.tapestry.services.impl.ExpressionEvaluatorImpl.read(
ExpressionEvaluatorImpl.java:82)
    at
org.apache.tapestry.contrib.table.model.ognl.OgnlTableColumnEvaluator.getColumnValue
(OgnlTableColumnEvaluator.java:56)
    at
org.apache.tapestry.contrib.table.model.simple.SimpleTableColumn.getColumnValue
(SimpleTableColumn.java:208

what is my wrong