试图从 List 在 jsp 中实现 jstl

Question

这是我的 Java 代码：

   List<EmployeeBean>questionList=adao.displayQuestions(eBean,functional_id);
   model.addObject("questionList", questionList);

   Iterator<EmployeeBean> iterator = questionList.iterator();
    while (iterator.hasNext()) {
       String q_id =iterator.next().getSk_question_id();
       System.out.println("QUESTION ID :"+q_id);
       List<EmployeeBean>optionList= adao.displayOptions(eBean,q_id);
       model.addObject("optionList", optionList);
      }

字符串 q_id 将基于第一个列表（questionList）有多个 id。 根据q_id，我会从第二个列表（optionList）中得到多个选项。

这是我在 jsp 中尝试的： 我无法获得 optionList 值。仅获取列表的最后一个值

  <c:forEach var="EmployeeBean" items="${questionList}">
   ${EmployeeBean.question_name }

     <c:forEach var="EmployeeBean" items="${optionList}">
       <div class="col-xs-4 starategy-data">
       <div class="strategy-head">${EmployeeBean.answer_type }</div>
       <p>${EmployeeBean.answer }</p>
       </div>
     </c:forEach>
  </c:forEach>

Answer 1

一种可能的方式（可能显示不正确，如果q_id没有相关数据列表）：

   List<EmployeeBean>questionList=adao.displayQuestions(eBean,functional_id);
   model.addObject("questionList", questionList);

   List<List<EmployeeBean>> resultList = new ArrayList<>();
   Iterator<EmployeeBean> iterator = questionList.iterator();
   while (iterator.hasNext()) {
          String q_id = iterator.next().getSk_question_id();
          System.out.println("QUESTION ID :"+q_id);
          resultList.add(adao.displayOptions(eBean,q_id));//store it by index
   }
   model.addObject("optionList", resultList);

JSP 代码：

 <c:forEach var="EmployeeBean" items="${questionList}" varStatus="status">
   ${EmployeeBean.question_name }

     <c:forEach var="EmployeeBean" items="${optionList.get(status.index)}"><!-- get the related data list -->
       <div class="col-xs-4 starategy-data">
       <div class="strategy-head">${EmployeeBean.answer_type }</div>
       <p>${EmployeeBean.answer }</p>
       </div>
     </c:forEach>
  </c:forEach>

---

另一种方式（我没试过，你可以测试）

Java 代码：

   List<EmployeeBean>questionList=adao.displayQuestions(eBean,functional_id);
   model.addObject("questionList", questionList);

   int index = 0;
   while (iterator.hasNext()) {
          String q_id = iterator.next().getSk_question_id();
          System.out.println("QUESTION ID :"+q_id);
          model.addObject("optionList_"+index,adao.displayOptions(eBean,q_id));
          index++;
   }

JSP 代码：

<c:forEach var="EmployeeBean" items="${questionList}" varStatus="status">
   ${EmployeeBean.question_name }

     <c:forEach var="EmployeeBean" items="${optionList_status.index}"><!-- not sure if it can work correct here -->
       <div class="col-xs-4 starategy-data">
       <div class="strategy-head">${EmployeeBean.answer_type }</div>
       <p>${EmployeeBean.answer }</p>
       </div>
     </c:forEach>
  </c:forEach>

Answer 2

试试这个：

   List<EmployeeBean>questionList=adao.displayQuestions(eBean,functional_id);
   model.addObject("questionList", questionList);


   List<EmployeeBean>optionList = new ArrayList<>();
   Iterator<EmployeeBean> iterator = questionList.iterator();
   while (iterator.hasNext()) {
          String q_id =iterator.next().getSk_question_id();
          System.out.println("QUESTION ID :"+q_id);
          optionList.addAll(adao.displayOptions(eBean,q_id)); 
   }
   model.addObject("optionList", optionList);