我有一个servlet从HTML下拉页面获取参数。点击按钮时,数据被发送到servlet。它首次发送数据,但如果我留在页面上并从下拉菜单 中选择不同的值并单击提交按钮,则新数据未设置到会话变量中。会话变量不会通过servlet提交
我的servlet位于下面。我需要修改DoGet
方法吗?同样,它第一次工作,但会话变量之后不会改变。
@WebServlet("/ListStudentServlet")
public class ListStudentServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
public ListStudentServlet() {
super();
// TODO Auto-generated constructor stub
}
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
}
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
String sessid = request.getParameter("studentid");
ArrayList<FactStudentDataBean> result = new ArrayList<>();
try (Connection con = JdbcUtil.getConnection()) {
String sql= "select F.Sessionid "
+ "from FACT_STUDENT F "
+ "where studentid = '"+sessid+"';";
try (Statement st = con.createStatement()) {
ResultSet rs = st.executeQuery(sql);
while (rs.next()){
result.add(new FactStudentDataBean(rs.getString(1)));
}
for (FactStudentDataBean factStudentDataBean : result) {
sessid = factStudentDataBean.getSessid();
}
} catch (Exception e) {
e.printStackTrace();
}
}
catch (Exception e) {
e.printStackTrace();
}
//Trying to set the session variable below, works the first time but anything after doesn't change
HttpSession session = request.getSession(true);
session.setAttribute("sessid", sessid);
}
}
'request.getSes sion(true)'如果会话尚不存在,则创建一个新会话。会话cookie是否被设置为下一次提交? –
我该如何设置? – thedude865