Question

我有一个java servlet，它将一个数组传递给一个jsp页面，在那个jsp页面上它显示了一堆结果。我想要做的是当它打印出来时打印一个链接，所以我可以用它作为参数。在我的例子中它打印出一堆实验室类，我想要发生的是他们点击与该实验室相关的链接然后我点击链接并可以在sql语句中使用该lab.id。

这是要打印的数组的代码

这是servlet

private void sendBack(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    HttpSession session = request.getSession(true);

        //Set data you want to send back to the request (will be forwarded to the page)
    //Can set string, int, list, array etc.
    //Set data you want to send back to the request (will be forwarded to the page)
    //Can set string, int, list, array etc.
    String sql = "SELECT s.name, l.time, l.day, l.room" +
              " FROM lab l, subject s, user_lab ul" +
            " WHERE ul.user_id=" + (Integer)session.getAttribute("id") +" AND ul.lab_id ="+ "l.id"+" AND l.subject_id ="+"s.id";

  try{
    Connection con = DriverManager.getConnection("jdbc:mysql://localhost:3306/wae","root","");
    System.out.println("got boobs");
    System.out.println(session.getAttribute("id"));

      Statement stmt = con.createStatement();
      ResultSet res = stmt.executeQuery(sql);
      System.out.println(res);
      ArrayList<String> list1 = new ArrayList<String>();
      if (res.next()){
          do{
               list1.add(res.getString(1) + " " + res.getString(2) +" "+ res.getString(3) + " " + res.getString(4));
               System.out.print(res.getString(1) +  res.getString(2));
          }while(res.next());
      System.out.println("Outside");
      String[] arr = list1.toArray(new String[list1.size()]);
      request.setAttribute("res", arr);
      }




  }catch (SQLException e) {
    } 
    catch (Exception e) {
    } 


    //Decides what page to send the request data to
    RequestDispatcher view = request.getRequestDispatcher("Lecturer_labs.jsp");
    //Forward to the page and pass the request and response information
    view.forward(request, response);

这是jsp页面

<h3>Manage Labs</h3>
<table>
<% String[] list1 = (String[])request.getAttribute("res");
         if(null == list1){%>

<% 
         }else{
        for(int i=0; i<list1.length; i++)
        {   %>
        <tr><%out.println(list1[i] + "<br/>");%></tr>        
    <%  }
        }
        %>
        </table>

那么如何才能将结果打印为传递参数的链接

Answer 1

要将结果显示为传递参数id的链接，每个链接可能如下所示：

<a href="/myapp/mypage.jsp?id="<%out.println(list1[i]);%>">Link <%out.println(list1[i]);%></a>

但看起来这看起来多么笨重。

JSTL tags 可以消除所有这些scriptlet代码：

<c:forEach items="${res}" var="id">
   <tr><td><a href="/myapp/mypage.jsp?id=${id}">Link ${id}</a></td></tr>
</c:forEach>

Servlet Jsp阵列打印链接

1 个答案: