//获取页面修改之前的信息（部分代码）

//获取页面修改之前的信息（部分代码） String sid = req.getParameter("id"); int id = Integer.parseInt(sid); String name = req.getParameter("name"); String pass = req.getParameter("pass"); System.out.println(name+"-----------"+pass); UserDTO userDTO = new UserDTO(); userDTO.setName(name); userDTO.setPassword(pass); //sql String sql = "update p_user set name = ?,password = ?, where id = ?"; Dao dao = new Dao(); int count = dao.getUpdate(sql, userDTO); String url = ""; if(count > 0){ url = "userList.jsp"; }else{ url = "error.jsp"; req.setAttribute("error", "更新"); } req.getRequestDispatcher(url).forward(req, resp); dao层public int getUpdate(String sql,UserDTO userDTO){ int count = 0; try { pre = connection.prepareStatement(sql); pre.setInt(5,userDTO.getId()); pre.setString(1, userDTO.getName()); pre.setString(2, userDTO.getPassword()); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } finally { try{ pre.close(); connection.close(); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } } return count; }上面多一个逗号,我已经删掉,那里不是主要原因,Parameter index out of range (5 > number of parameters, which is 3)