java - JSP页面仅接收第一个arrayList

在jsp页面中，它仅打印首先访问的功能。如果首先访问功能1，则不会打印功能2。并且，如果首先访问Function-2，则不会打印Function-1。有任何建议请。

控制器：

populateTf(tfCount, request, response);
populateSa(saCount, request, response);

response.sendRedirect("testPage.jsp");

//FUNCTION-1
void populateTf(int tfCount, HttpServletRequest request, HttpServletResponse response){
    ArrayList<TF> tfList = new ArrayList<TF>();

    String field1 = request.getParamter("xyz");
    String field2 = request.getParamter("xyz");
    String field3 = request.getParamter("xyz");

    tfList.add(new TF(field1, field2, field3));

    HttpSession session = request.getSession();
    session.setAttribute("tfList", tfList);
}

//FUNCTION-2
void populateSa(int saCount, HttpServletRequest request, HttpServletResponse response){
    ArrayList<SA> saList = new ArrayList<SA>();

    String field1 = request.getParamter("xyz");

    saList.add(new SA(field1));

    HttpSession session = request.getSession();
    session.setAttribute("saList", saList);
}

业务对象：

public class TF{
    private String field1, field2, field3;
    public TrueFalse(String field1, String field2, String field3) {
        this.field1 = field1;
        this.field2 = field2;
        this.field3 = field3;
    }
    /* GETTERS AND SETTERS */
}

public class SA{
   private String field1;
   public ShortAnswer(String field1) {
      this.field1 = field1;
   }
   /* GETTERS AND SETTERS */
}

这是JSP页面：

<table>
        <c:forEach items="${sessionScope.tfList}" var="tf">
        <tr>
                <td>${tf.field1}</td>
                <td>${tf.field2}</td>
                <td>${tf.field3}</td>
        </tr>
        </c:forEach>
</table>

<table>
        <c:forEach items="${sessionScope.saList}" var="sa">
        <tr>
                <td>${sa.field1}</td>
        </tr>
        </c:forEach>
</table>

最佳答案

也许不要调用两次request.getSession()，而是创建一个全局变量以将会话保留在servlet中，然后仅调用一次request.getSession()。我也不认为需要将请求和响应传递给这两个函数。

private HttpSession session = null;

public void doGet(HttpServletRequest request, HttpServletResponse  response) throws IOException, ServletException
{
    session = request.getSession();
    ....
    populateTf(tfCount);
    populateSa(saCount);
    ....
}

private void populateTf(int tfCount)
{
    ArrayList<TF> tfList = new ArrayList<TF>();

    .... //where is field1, field2, field3 coming from anyway?

    tfList.add(new TF(field1, field2, field3));

    session.setAttribute("tfList", tfList);
}

private void populateSa(int saCount)
{
    ArrayList<SA> saList = new ArrayList<SA>();

    .... //where is field1 coming from anyway?

    saList.add(new SA(field1));

    session.setAttribute("saList", saList);
}