Jsp 如何根据jstl中另一个lis的索引值迭代hashmap_Jsp_Jstl

Jsp 如何根据jstl中另一个lis的索引值迭代hashmap

jsp

Jsp 如何根据jstl中另一个lis的索引值迭代hashmap,jsp,jstl,Jsp,Jstl,我有一个存储在arraylist问题列表中的问题列表和一个hashmap，其签名是Map存储每个问题的答案。我已将整数值与问题列表的索引值映射。现在我想在jsp中打印每个问题及其相应的答案 <c:set var="form" value="${surveyQuestionnaire}"/> <c:forEach var="questionName" items="${form.questionsList }" varStatus="theCount"> Q.<

我有一个存储在arraylist问题列表中的问题列表和一个hashmap，其签名是

Map

存储每个问题的答案。我已将整数值与问题列表的索引值映射。现在我想在jsp中打印每个问题及其相应的答案

<c:set var="form" value="${surveyQuestionnaire}"/>
<c:forEach var="questionName" items="${form.questionsList }"   varStatus="theCount">
 Q.<c:out value="${questionName}"></c:out>
 <c:forEach var="questionAnswerMap" items="${form.queChoicesMap }"  >
 </c:forEach>
</c:forEach>

因此，我没有找到获取给定键的值的方法，该键将是问题列表的索引，并在列表中迭代以打印所有答案，这里是演示代码

<%@ taglib prefix = "c" uri = "http://java.sun.com/jsp/jstl/core" %>
<c:set var="questionList" value='${["What color is the sky?","Who invented the telephone?","Which country has the biggest population?"]}'/>
<c:set var="queChoicesMap" value='${{1:["green","brown","blue"],2:["Smith","Bell","Jones"],3:["China","India","USA"]}}'/>
<html>
    <body>
            <c:forEach items="${questionList}" var="question" varStatus="status">
               ${question}
               <c:forEach items="${queChoicesMap[(status.count).longValue()]}" var="choice" varStatus="choiceStatus">
                <br/> ${choiceStatus.count})${choice} 
                </c:forEach> <br/>
            </c:forEach>
    </body> 
</html>

如果您使用的是旧版本，则可以使用以下代码之一。
但是，他们有一个丑陋的脚本。这些scriptlet中的代码应该转移到“标记文件”或“自定义EL函数”中


${问题}

${choiceStatus.count}）${choice}

及


${问题}

${choiceStatus.count}）${choice}

这引发了一个语法错误“当未指定默认名称空间时，函数longValue必须与前缀一起使用”请告诉我们您正在使用的服务器和EL版本以及适用于您的代码。

Server Version: 
${pageContext.servletContext.serverInfo}  
Servlet Version: 
${pageContext.servletContext.majorVersion}.${pageContext.servletContext.minorVersion}

<%@page import="java.util.*" %>
<%@ taglib prefix = "c" uri = "http://java.sun.com/jsp/jstl/core" %>
<%
    ArrayList<String> questionList = new ArrayList<String>();
    questionList.add("What color is the sky?");
    questionList.add("Who invented the telephone?");
    questionList.add("Which country has the biggest population?");
    pageContext.setAttribute("questionList", questionList);
    ArrayList<String> listOne = new ArrayList<String>();
    listOne.add("green");
    listOne.add("brown");
    listOne.add("blue");
    ArrayList<String> listTwo = new ArrayList<String>();
    listTwo.add("Smith");
    listTwo.add("Bell");
    listTwo.add("Jones");
    ArrayList<String> listThree = new ArrayList<String>();
    listThree.add("China");
    listThree.add("India");
    listThree.add("U.S.A.");
    HashMap<Integer,List<String>> choicesMap = new HashMap<Integer,List<String>>();
    choicesMap.put(1, listOne);
    choicesMap.put(2, listTwo);
    choicesMap.put(3, listThree);
    pageContext.setAttribute("choicesMap", choicesMap);
%>
<html>
    <body>
            <c:forEach items="${questionList}" var="question" varStatus="status">
                ${question}

                <c:forEach items="${choicesMap[status.count]}" var="choice" varStatus="choiceStatus">
                    <br/> ${choiceStatus.count})${choice} 
                </c:forEach> <br/>
            </c:forEach>
    </body> 
</html>

<%@page import="javax.servlet.jsp.jstl.core.LoopTagStatus" %>
<%@ taglib prefix = "c" uri = "http://java.sun.com/jsp/jstl/core" %>
<c:set var="questionList" value='${["What color is the sky?","Who invented the telephone?","Which country has the biggest population?"]}'/>
<c:set var="choicesMap" value='${{1:["green","brown","blue"],2:["Smith","Bell","Jones"],3:["China","India","U.S.A."]}}'/>
<html>
    <body>
            <c:forEach items="${questionList}" var="question" varStatus="status">
                ${question}
                <%
                    LoopTagStatus status = (LoopTagStatus)pageContext.getAttribute("status");
                    long count = new Integer(status.getCount()).longValue();
                    pageContext.setAttribute("count", count);
                %>
                <c:forEach items="${choicesMap[count]}" var="choice" varStatus="choiceStatus">
                    <br/> ${choiceStatus.count})${choice} 
                </c:forEach> <br/>
            </c:forEach>
    </body> 
</html>