"下一步"按钮不递增变量 JSP

Question

我目前正在JSP中创建一个在线测验，该测验使用存储在数据库中的答案和问题。每个问题及其可能的答案都与 1-20 之间的整数链接，形成 20 个问题。为了访问这些问题，我使用名为 QID 的 IN 参数创建了存储过程。

我的问题是，如何创建一个"下一步"按钮来递增 QID 并将用户发送到下一个问题？我听说过使用 AJAX，但不确定如何使用它。一个示例案例是用户回答问题 1，然后单击"下一步"按钮，QID 递增到 2，然后显示问题 2，依此类推。

这是我的代码(我知道我不应该在JSP中使用scriptlet;这将在项目开发后解决(：

<% 
Connection conn = null;
ResultSet rs = null;
Statement st = null;
String action;
Scanner input = new Scanner(System.in);
int score = 0;
int QID;
try {
Class.forName("org.mariadb.jdbc.Driver");
System.out.println("Connecting to a selected database...");
conn = DriverManager.getConnection(
"jdbc:mariadb://ebs-db.eastbarnetschool.com/Kishen", "Kishen","doctor9");
System.out.println("Connection made");
CallableStatement stmt = conn.prepareCall("{call GetQuestionTitle(?, ?)}");
stmt.setInt(1, QID); 
stmt.registerOutParameter(2, Types.VARCHAR);
stmt.execute();
String description = stmt.getString(2);
System.out.println(description);
%>
<% 
CallableStatement answer1 = conn.prepareCall("{call GetAnswer1(?, ?)}");
answer1.setInt(1, QID); 
answer1.registerOutParameter(2, Types.VARCHAR);
answer1.execute();
String answerOne = answer1.getString(2);
System.out.println(answerOne);
CallableStatement answer2 = conn.prepareCall("{call GetAnswer2(?, ?)}");
answer2.setInt(1, QID); 
answer2.registerOutParameter(2, Types.VARCHAR);
answer2.execute();
String answerTwo = answer2.getString(2);
System.out.println(answerTwo);
CallableStatement answer3 = conn.prepareCall("{call GetAnswer3(?, ?)}");
answer3.setInt(1, QID); 
answer3.registerOutParameter(2, Types.VARCHAR);
answer3.execute();
String answerThree = answer3.getString(2);
System.out.println(answerThree);
CallableStatement answer4 = conn.prepareCall("{call GetAnswer4(?, ?)}");
answer4.setInt(1, QID); 
answer4.registerOutParameter(2, Types.VARCHAR);
answer4.execute();
String answerFour = answer4.getString(2);
System.out.println(answerFour);
%>
<%
String chosenAnswer=" ";
if(request.getParameter("button")!=null)
{
chosenAnswer=request.getParameter("button").toString();
}
CallableStatement stmt2 = conn.prepareCall("{call GetCorrectAnswer(?, ?)}");
stmt2.setInt(1, QID); 
stmt2.registerOutParameter(2, Types.VARCHAR);
stmt2.execute();
String CorrectDescription = stmt2.getString(2);
System.out.println("nCorrect Answer: " + CorrectDescription);
if(request.getParameterValues("button") != null) {
if(chosenAnswer.equals(CorrectDescription)) {
score ++;
%>
<h4 align="center"><font color="green" face="arial">You got Question <%=QID%> correct!</font></h4>
<%
}   
else{
%>
<h4 align="center"><font color="red" face="arial">You got Question <%=QID%> incorrect!</font></h4>
<%  
}   
}   
%> 
<br>
<br>
<center>
<table border="1" width="500px" bgcolor="lightblue" cellspacing="0" cellpadding="0">
<tr>
<td width="100%">
<form name="Quiz" method="get" action='Quiz.jsp'>
<h1 align="center"><font color="white" face="arial">Quiz</font></h1>
<table border="0" width="500px" cellspacing="2" cellpadding="6">
<tr>
<td width="50%"><font color="steelblue" face="arial" size=4><span style="font-weight:normal"> QUESTION <%=QID%></span></font></td>
<tr>
<td width="100%"><font color="black" face="arial" size=4><span style="font-weight:normal"><%=description%></span></font></td></tr>
<tr>
<td>        
1: <input type="radio" name="button" value= "<%=answerOne%>" /><font face="arial" size=3><%=answerOne%></font></td>
<tr>
<td>
2: <input type="radio" name="button" value="<%=answerTwo%>" /><font face="arial" size=3><%=answerTwo%></font></td>
<tr>
<td>
3: <input type="radio" name="button" value="<%=answerThree%>" /><font face="arial" size=3><%=answerThree%></font></td>
<tr>
<td>
4: <input type="radio" name="button" value="<%=answerFour%>" /><font face="arial" size=3><%=answerFour%></font></td>
<tr><td><center>

<%
int pageStart = 1;
String start = request.getParameter("start");
if(start != null)pageStart = Integer.parseInt(start);
%>
<input type="submit" value="Next" name="next" ONCLICK = <%=QID=QID+1%>
<%
if (request.getParameter("next") != null){
QID ++;
}
%>
</center></td></tr> 
</table>
</form>
</td>
</tr>
</table>
</center>

Answer 1

AJAX 用于异步方法，这意味着您保持在同一页面

要转到下一个问题，您最好将用户发送到问题的页面

<input name="qid" type="HIDDEN" value="<%=QID+1%>">