在servlet向jsp循环输出数据

HttpSession session = request.getSession();
session.setAttribute("user",user);

private String selectHolding = "select * from holding where user_name=?";

//查看当前持仓股票情况
public List selectHolding(String user_name) {

List<Holding> list = new ArrayList<Holding>();

Holding holding = null;
Connection conn = null;
PreparedStatement pst = null;
ResultSet rs = null;

try {
conn = pool.getConnection();
pst = conn.prepareStatement(this.selectHolding);

pst.setString(1,user_name);

rs = pst.executeQuery();
while(rs.next()){
holding = new Holding();

holding.setHolding_id(rs.getInt("holding_id"));
holding.setStock_id(rs.getInt("stock_id"));
holding.setNum(rs.getInt("num"));
holding.setAvgprice(rs.getDouble("avgprice"));
holding.setUser_id(rs.getInt("user_id"));

list.add(holding);
}

} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}finally{
if(pst!=null && rs!=null){
try {
rs.close();
pst.close();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
pool.freeConntion(conn);
}
return list;
}

//获得某个用户的持仓
HttpSession session = request.getSession();
User user =(User)session.getAttribute("user");
String username = user.getName();
HoldingDaoOption ts = new HoldingDaoOption();
List list2 = (List)ts.selectHolding(username);

request.setAttribute("holdinglist", list2);
request.getRequestDispatcher("trade.jsp").forward(request, response);

<%
ArrayList list2 = null;
list2 = (ArrayList)request.getAttribute("holdinglist");
Holding holding = null;
//float sum2 = 0;
if(list2!=null){
for(int i=0;i<list2.size();i++){
holding = new Holding();
holding = (Holding)list2.get(i);
%>
<tr>
<td><%=holding.getHolding_id() %></td>
<td><%=holding.getStock_id() %></td>
<td><%=holding.getNum() %></td>
<td><%=holding.getAvgprice() %></td>
<td><%=holding.getUser_id() %></td>
</tr>

<%}}else{ %>
<tr><td>数据不存在</td></tr>
<%} %>