I need your help. Actually I developed an online quiz in struts1.3.it is
working fine but when I finished my test and close the browser window and
登录然后我发现所有单选按钮都标记为关闭窗口之前。 我正在使用java hashmap来存储用户响应（qno。，ans）。 当我在结果行之后清除了hashmap然后它显示了一个 空指针异常。 请告诉我应该怎么做才能清除用户响应 关上窗户后。 我正在使用会话将地图移动到多个页面以获得结果。 请帮忙
<%@page import="com.myapp.struts.Question"%>
<%@page import="java.util.*"%>
<%@page import="java.util.TreeMap"%>
<%@page import="java.util.Map"%>
<%@page import="com.myapp.struts.Db"%>
<%@page contentType="text/html" pageEncoding="UTF-8"%>
<%@page import="com.myapp.struts.MyBean"%>
<%@page import="java.util.Iterator"%>
<%@page import="java.util.List"%>
<%@ taglib uri="http://struts.apache.org/tags-bean" prefix="bean" %>
<%@ taglib uri="http://struts.apache.org/tags-html" prefix="html" %>
<%@ taglib uri="http://struts.apache.org/tags-logic" prefix="logic" %>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<%@page import="com.myapp.struts.ActionQuestion"%>
<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>JSP Page</title>
<link rel="stylesheet" type="text/css"
href="css/bootstrap.min.css">
<style>
<style type="text/css">
.bs-example{
margin: 20px;
}
</style>
</style>
<script src="js/jquery-3.2.1.min.js"></script>
<script src="js/bootstrap.min.js"></script>
<script>
<!--
//edit this message to say what you want
var message = "Right Click Not Allowed";
function clickIE() {
if (document.all) {
alert(message);
return false;
}
}
function clickNS(e) {
if (document.layers || (document.getElementById && !document.all)) {
if (e.which == 2 || e.which == 3) {
alert(message);
return false;
}
}
}
if (document.layers) {
document.captureEvents(Event.MOUSEDOWN);
document.onmousedown = clickNS;
}
else {
document.onmouseup = clickNS;
document.oncontextmenu = clickIE;
}
document.oncontextmenu = new Function("return false")
// -->
</script>
<font>Banner</font>
<%!
static int qid=0;
Map<Integer,Integer> userans=new LinkedHashMap<Integer,Integer>
();
Map<Integer,Integer> dbans=new LinkedHashMap<Integer,Integer>();
int count=0;List list;
static int qcounter=1;
int qidsetbutton=0;
Question app=null;
int useroption=0;
int userres=0;
%>
<%
String sess = (String)session.getAttribute("user");
out.println("User-Id:"+sess);
if( sess==null || sess.equals(""))
{
response.sendRedirect("UnAuthorisedAccess.jsp");
}
if(request.getAttribute("list")!=null)
{
list=(List)request.getAttribute("list");
}
String button= request.getParameter("button1");
count=list.size();
%>
<script type="text/javascript">
function saveanswer() // Save Answer when user click on any radio
button
{
var useroption = document.querySelector('input[name =
"my"]:checked').value;
window.location.replace("TakeTest.jsp?useroption="+useroption);
alert("hi"+useroption);
}
</script>
<%
if(request.getParameter("useroption")!=null)
{
try{
useroption= Integer.parseInt(request.getParameter("useroption"));
out.println("Rrrrrrrrrrrrrr"+useroption);
out.println("app.qid="+app.qid());
userans.put(app.qid(),useroption);
dbans.put(app.qid(),app.sol());
session.setAttribute("map",userans);
session.setAttribute("dbans",dbans);
}catch(Exception ex)
{
out.println(" problem during question answer save "+ex);
}
}
%>
<%
if(request.getParameter("q")!=null)
{
qid= Integer.parseInt(request.getParameter("q"));
app=(Question)list.get(qid);
}
//String str = "<script>document.writeln(name)</script>";
//out.println("value: " + str);
%>
<%
session.setAttribute("count",count);
if(qid==0)
{
app=(Question)list.get(0);
}
try{
if(button.equals("Next") && qid<count)
{
//map3.put(qid,request.getParameter("my"));
//new Db().userResponse(qid,request.getParameter("my"));
qcounter=qcounter+1;
qid=qid+1;
app=(Question)list.get(qid);
userres=userans.get(app.qid());
}
}catch(Exception ex)
{
//out.println("probleme in next section "+ex);
}
try{
if(button.equals("Previous") && (qid>0 & qcounter>1))
{
qid=qid-1;
qcounter=qcounter-1;
app=(Question)list.get(qid);
userres=userans.get(app.qid());
%>
<%
}
}catch(Exception ex)
{
//out.println("probleme in prevoius "+ex);
}%>
<script type="text/javascript">
function qidset()
{
<%
try{
if(request.getParameter("qidsetbutton")!=null)
{
qidsetbutton = Integer.parseInt(request.getParameter("qidsetbutton"));
qcounter=qidsetbutton;
qid=qidsetbutton-1;
app=(Question)list.get(qid);
userres=userans.get(app.qid());
}
}catch(Exception ex)
{
out.println("probleme button refernec section "+ex);
}%>
%>
}
</script>
<script type="text/javascript">
function hide()
{
if(<%=qcounter%> == 1)
{
document.getElementById('myButton').disabled =true;
}
else if(<%=qcounter%>==<%=list.size()%>)
{
document.getElementById('myButton1').disabled =true;
}
}
</script>
<script type="text/javascript">
function start()
{
//startTimer();
hide();
}
</script>
<style>
#qid {
padding: 10px 15px;
-moz-border-radius: 50px;
-webkit-border-radius: 50px;
border-radius: 20px;
}
label.btn {
padding: 18px 60px;
white-space: normal;
-webkit-transform: scale(1.0);
-moz-transform: scale(1.0);
-o-transform: scale(1.0);
-webkit-transition-duration: .3s;
-moz-transition-duration: .3s;
-o-transition-duration: .3s
}
label.btn:hover {
text-shadow: 0 3px 2px rgba(0,0,0,0.4);
-webkit-transform: scale(1.1);
-moz-transform: scale(1.1);
-o-transform: scale(1.1)
}
label.btn-block {
text-align: left;
position: relative
}
label .btn-label {
position: absolute;
left: 0;
top: 0;
display: inline-block;
padding: 0 10px;
background: rgba(0,0,0,.15);
height: 100%
}
label .glyphicon {
top: 34%
}
body {
background-color: #;
}
</style>
</head>
<body onload="start()" >
<% out.println("herererer"+userres); %>
<br><br>
<center> <html:form action="/Result">
<button type="submit" name="button1" class="btn btn-primary btn-danger">Finish</button>
</html:form>
</center>
</center>
<br><br>
<html:form action="/question">
<div class="container" >
<div class="row"> <%-- paralle conntent--%>
<div class="col-xs-6">
<div class="span12">
<table border="1" align="center" height="100%" width="150%">
<tr>
<td height="100"><font size="3">Q No.<%=qcounter%> <%=app.stmt()%></font>
</td>
</tr>
<tr>
<div class="quiz" id="quiz" data-toggle="buttons">
<td>
<label class="element-animation1 btn btn-lg btn-primary btn-block "><span class="btn-label"><i class="glyphicon glyphicon-chevron-right"></i></span> <input type="radio" id="opt1" name="my" value="1" <%= (userres==1)?"checked":""%> onchange="saveanswer()" /><%=app.opt1()%></label>
<br>
</td>
</tr>
<tr>
<td>
<label class="element-animation1 btn btn-lg btn-primary btn-block "><span class="btn-label"><i class="glyphicon glyphicon-chevron-right"></i></span> <input type="radio" id="opt2" name="my" value="2" <%= (userres==2)?"checked":""%> onchange="saveanswer()" /><%=app.opt2()%></label>
<br>
</td>
</tr>
<tr>
<td>
<label class="element-animation1 btn btn-lg btn-primary btn-block ">
onchange =“saveanswer（）”/＆gt;＆lt;％= app.opt3（）％＆gt;
<br>
</td>
</tr>
<tr>
<td>
<label class="element-animation1 btn btn-lg btn-primary btn-block
"><span class="btn-label"><i class="glyphicon glyphicon-chevron-right"></i>
</span> <input type="radio" id="opt4" name="my" value="4" <%=
(userres==4)?"checked":""%> onchange="saveanswer()" /><%=app.opt4()%>
</label>
</td>
</tr>
</div>
</tr>
<%
userres=0;
%>
<tr td height="60" align="center">
<td>
<button type="submit" id="myButton" name="button1"
value="Previous" class="btn btn-success">Previous</button>
<button type="submit" id="myButton1" name="button1" value="Next"
class="btn btn-success">Next</button>
</td>
</tr>
</html:form>
</table>
</div>
</div>
<div class="col-xs-6">
<html:form action="/question"> <%--pallete code in which click on pallete button reach to particular questions--%>
<table border="1" width=50% height=40% align="right" style="font-family: Arial;color:black;font-weight: bold" cellspacing=10 cellpadding=10 >
<tr><td align="right">Pallete Preview</td></tr>
<%
int nq=count;
int col_lastrow=nq%3;
int rows;
int c=0;
if(col_lastrow==0)
rows=nq/3;
else
rows=(nq/3)+1;
for(int j=0;j<rows;j++)
{
%>
<tr align=center style="height:5px">
<%
if(j<(rows-1))
{
for(int i=0;i<3;i++)
{
c++;
%>
<td id="<%=c%>"style="width:50px;height:2px;">
<button type="submit" id="setqid" name="qidsetbutton" value="<%=c%>" class="btn btn-toolbar btn-block" onclick="qidset()"><%=c%></button>
<%
}
%>
</tr>
<%
}
else
{
if(col_lastrow==0)
col_lastrow=3;
for(int i=0;i<col_lastrow;i++)
{
c++;
%>
<td id="<%=c%>"style="width:50px;height:2px;">
<button type="submit" id="setqid" name="qidsetbutton" value="<%=c%>" class="btn btn-toolbar btn-block" onclick="qidset()"><%=c%></button>
<%
}
}
%>
</tr>
<%
}
%>
</table>
</div> </div>
</div>
</html:form>
</body>
</html>
**Result.jsp**
<%@page import="java.util.ArrayList"%>
<%@page import="java.util.List"%>
<%@page import="java.util.Collection"%>
<%@page import="java.util.Set"%>
<%@page import="java.util.Map"%>
<%@page import="com.myapp.struts.Db"%>
<%@page import="com.myapp.struts.ActionQuestion"%>
<%@page contentType="text/html" pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>JSP Page</title>
<script>
<!--
//edit this message to say what you want
var message = "Right Click Not Allowed";
function clickIE() {
if (document.all) {
alert(message);
return false;
}
}
function clickNS(e) {
if (document.layers || (document.getElementById && !document.all)) {
if (e.which == 2 || e.which == 3) {
alert(message);
return false;
}
}
}
if (document.layers) {
document.captureEvents(Event.MOUSEDOWN);
document.onmousedown = clickNS;
}
else {
document.onmouseup = clickNS;
document.oncontextmenu = clickIE;
}
document.oncontextmenu = new Function("return false")
// -->
</script>
</head>
<body>
<%!
Db db=null;
int count=0;
int correct=0;
int incorrect=0;
int attempt=0;
int unattempt=0;
double percentage;
Map map1=null;
Map map2=null;
%>
<%
String sess = (String)session.getAttribute("user");
out.println("User-Id:"+sess);
if( sess==null || sess.equals(""))
{
response.sendRedirect("UnAuthorisedAccess.jsp");
}
if(session.getAttribute("map")!=null)
{
map1=(Map)session.getAttribute("map"); //user response map
map2=(Map)session.getAttribute("dbans"); //database answer map
Integer count=(Integer)session.getAttribute("count");
Set <Integer>s1=map1.keySet();
Set <Integer>s2=map2.keySet();
Collection cl=map1.values();
Collection c2=map2.values();
List map1value=new ArrayList();
map1value.addAll(cl);
List map2valu=new ArrayList();
map2valu.addAll(c2);
out.println(map1value.get(0));
out.println(map2valu.get(0));
List map1key=new ArrayList(s1);
List map2key=new ArrayList(s2);
for(int i=0;i<map1key.size();i++)
{
if(map1key.get(i).equals(map2key.get(i)))
{
if(map1value.get(i).equals(map2valu.get(i)))
{
out.println(map1value.get(i));
out.println(map2valu.get(i));
++correct;
}
else
{
++incorrect;
}
}
else
{
++incorrect;
}
}
attempt=correct+incorrect;
unattempt=count-attempt;
percentage=Math.round((correct*100.0)/count);
%>
<br><br><br><br>
<center><font size="5" color="green">Result</font></center>
<br><br><br>
<table border="1" height="100" width="500" align="center">
<tbody align="center">
<tr style=" color: ">
<td>Total Questions:<%=count%></td>
</tr>
<tr style=" color: ">
<td>Right Answer:<%=correct%></td>
</tr>
<tr style=" color:">
<td>Wrong Answer:<%=incorrect%></td>
</tr>
<tr style=" color:">
<td>Attempted:<%=attempt%></td>
</tr>
<tr style=" color:">
<td>Not Attempted:<%=unattempt%></td>
</tr>
<tr style=" color:">
<td>Percentage:<%=percentage%><i>%</i></td>
</tr>
</tbody>
</table>
<%
}
else
{
out.println("you couldn't attempt any question so your result wouldn't consider");
}
%>
</body>
</html>
答案 0 :(得分：0)
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