JSP里怎么获得Session的值并存入数据库

<%    boolean userlogined = false;    String userLogined = (String) session.getAttribute("userId");    if (userLogined != null) {        userlogined = true;    }%><%    request.setCharacterEncoding("UTF-8");    String action = request.getParameter("action");    if (action != null && action.trim().equals("post")) {        String title = request.getParameter("title");        //System.out.println(title);        String cont = request.getParameter("cont");        //System.out.println(cont);        String name = request.getParameter("userlogined");        Connection conn = DB.getConn();        boolean autoCommit = conn.getAutoCommit();        conn.setAutoCommit(false);        int rootId = -1;        String sql = "insert into article values(null,?,?,?,?,now(),?,?)";        PreparedStatement pstmt = DB.prepareStmt(conn,sql,Statement.RETURN_GENERATED_KEYS);        pstmt.setInt(1, 0);        pstmt.setInt(2, rootId);        pstmt.setString(3, title);        pstmt.setString(4, cont);        pstmt.setInt(5, 0);        pstmt.setString(6,name);        pstmt.executeUpdate();                ResultSet rsKey = pstmt.getGeneratedKeys();            rsKey.next();        rootId = rsKey.getInt(1);        Statement stmt = DB.createStmt(conn);        stmt.executeUpdate("update article set rootid=" + rootId + " where id="+ rootId);                conn.commit();        conn.setAutoCommit(autoCommit);        DB.close(stmt);        DB.close(pstmt);        DB.close(conn);        response.sendRedirect("articleFlat.jsp");    }%>

<form action="post.jsp" method="post">                                    <input type="hidden" name="action" value="post" />                                                                        标题：                                    <input type="text" name="title">                                    <br>                                    内容：                                    <br>                                    <textarea name="cont" rows="15" cols="80"></textarea>                                    <br>                                    <input type="submit" value="提交" />                                </form>