JSP：<div class="person_main" align="center">?? ?<table cellspacing="10" cellpadding="10" align="center" width="65%">?? ?<%?? ?ArrayList lookList = (ArrayList)session.getAttribute("lookList");?? ?if(lookList==null||lookList.size()==0){?? ??? ?request.getRequestDispatcher("My.jsp").forward(request, response);?? ??? ?}?? ?else{?? ??? ?for(int i=lookList.size()-1;i>=0;i--){?? ??? ?MyMessBean mm = (MyMessBean)lookList.get(i);?? ? %>?? ??? ? <tr>?? ? ?? ?<td height="30px">用戶姓名</td>?? ? ?? ?<td><%=mm.getName() %></td>?? ? </tr>?? ?? <tr>?? ? ?? ?<td height="30px">用戶賬號</td>?? ? ?? ?<td><%=mm.getId() %></td>?? ? </tr>?? ?? <tr>?? ? ?? ?<td height="30px">用戶性別</td>?? ? ?? ?<td><%=mm.getSex() %></td>?? ? </tr>?? ?? <tr>?? ? ?? ?<td height="30px">用戶學歷</td>?? ? ?? ?<td><%=mm.getEdu() %></td>?? ? </tr><%}} %>Servlet:protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {?? ??? ?String userId = request.getParameter("userId");?? ??? ?try{?? ??? ??? ?Connection conn = null;?? ??? ??? ?Statement stmt = null;?? ??? ??? ?ResultSet rs = null;?? ??? ??? ?Class.forName("com.mysql.jdbc.Driver");?? ??? ??? ?String url = "jdbc:mysql://localhost:3306/javaweb?useUnicode=true&characterEncoding=utf-8&useSSL=false";?? ??? ??? ?conn = DriverManager.getConnection(url,"root","1997YJY");?? ??? ??? ?stmt=conn.createStatement();?? ??? ??? ?HttpSession session = request.getSession();?? ??? ??? ??? ??? ??? ?String sql ="select userId,userName,sex,edu from user where userId='"+userId+"'";?? ??? ??? ?rs=stmt.executeQuery(sql);?? ??? ??? ??? ??? ??? ??? ??? ??? ?ArrayList lookList = new ArrayList();?? ??? ??? ?while(rs.next()){?? ??? ??? ??? ?MyMessBean mm = new MyMessBean();?? ??? ??? ??? ?mm.setId(rs.getString("userId"));?? ??? ??? ??? ?mm.setName(rs.getString("userName"));?? ??? ??? ??? ??? ??? ??? ??? ?mm.setSex(rs.getString("sex"));?? ??? ??? ??? ?mm.setEdu(rs.getString("edu"));?? ??? ??? ??? ?lookList.add(mm);?? ??? ??? ??? ??? ??? ??? ?}?? ??? ??? ?session.setAttribute("lookList", lookList);?? ??? ??? ??? ??? ??? ??? ??? ??? ?rs.close();?? ??? ??? ?stmt.close();?? ??? ??? ?conn.close();?? ??? ??? ?request.getRequestDispatcher("person.jsp").forward(request, response);?? ??? ?}catch(Exception e){?? ??? ??? ?e.printStackTrace();?? ??? ?}?? ?}bean:(geter seter方法）??? private String userId;?? ?private String userName;?? ?private String edu;?? ?private String sex;可是問題就是這個輸出數據庫信息的，得到的結果是lookList=null，為什么呢？小白求教，想要知道我該怎樣改正，才能轉發我要的那個頁面：（拜托啦