Question

Java id 编号怎么传递成空值了？在jsp中显示不出来id的值，一直为空

private void edit(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
String id = request.getParameter("id");
List list = null;
try {
String sql = "select name,level from category where id="+id;
list = (List) DbHelper.getQueryRunner().query(sql, new BeanListHandler(Category.class));
} catch (SQLException e) {
e.printStackTrace();
}
request.setAttribute("list", list);
request.getRequestDispatcher("/editCategory.jsp").forward(
request, response);

}
我已经知道了为什么会传递成空值了。原来String sql = "select name,level from category where id="+id;少写了个id号，查询出来的只有name,level两个值，所以在Jsp页面中获取不到。

Answer 1

你如果要用resultset取得话必须要把id也给select出来

Answer 2

仔细的看一下，好像没穿过去额……

Answer 3

你把代码放上来，才能排错。

Answer 4

加油~~~~~~~~~~~~~~~~~~~~~~~~~~

Answer 5

代码