我正在创建测验应用程序。在这里，有5个具有5个不同测验的jsp页面。如果我使用1个jsp页面和结果页面，则可以正常工作。它从QuizPage5.jsp重定向并在ResultPage.jsp中显示结果。我需要显示从QuizPage1.jsp，QuizPage2.jsp，QuizPage3.jsp，QuizPage4.jsp和QuizPage5.jsp到ResultPage.jsp的所有结果。
我用了
在jsp1中传递值。
<form action=""> <input type="hidden" name="hidden" value="hidden"> <input type="submit" value="submit"></form>
在jsp2中获取价值
String value=request.getParameter("hidden");
但是，我越来越 java.lang.NullPointerException
java.lang.NullPointerException
这是我的代码。
QuizPage1.jsp
<html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <script language="JavaScript"> function check() { var radio_choice = false; for (counter = 0; counter < myform.grp.length; counter++) { if (myform.grp[counter].checked) radio_choice = true; } if (!radio_choice) { alert("Please select one.") return (false); } return(true); } </script> </head> <body> <h3>Quiz No.1</h3> Q1.Which one of the following is the Capital of India?<br><br> <form action="QuizPage2.jsp" method="post" name="myform" onsubmit="return check();"> <input type="radio" name="grp" value="New Delhi" >New Delhi<br> <input type="radio" name="grp" value="Kolkata" >Kolkata<br> <input type="radio" name="grp" value="Chennai" >Chennai<br> <input type="radio" name="grp" value="Mumbai" >Mumbai<br> <br><br><input type="submit" value="Next Question"> <input type="hidden" name="hidden" value="grp"> <input type="submit" value ="Back" onclick="window.history.back();"/> </form> </body> </html>
QuizPage2.jsp
<html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <script language="JavaScript"> function check() { var radio_choice = false; for (counter = 0; counter < myform2.grp2.length; counter++) { if (myform2.grp2[counter].checked) radio_choice = true; } if (!radio_choice) { alert("Please select any one Answer"); return (false); } return(true); } </script> </head> <body> <h3>Quiz No.2</h3> Q2. Where is Chennai Located?<br><br> <form action="QuizPage3.jsp"method="post" name="myform2" onsubmit="return check();"> <input type="radio" name="grp2" value="Karnataka" >Karnataka<br> <input type="radio" name="grp2" value="Tamilnadu" >Tamilnadu<br> <input type="radio" name="grp2" value="Andhra Pradesh" >Andhra Pradesh<br> <input type="radio" name="grp2" value="Maharashtra" >Maharashtra<br> <br><br><input type="submit" value="Next Question"> <input type="hidden" name="hidden" value="grp2"> <input type="submit" value ="Back" onclick="window.history.back();"/> </form> <% String s1=request.getParameter("grp"); %> </body> </html>
QuizPage3.jsp
<html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <script language="JavaScript"> function check() { var radio_choice = false; for (counter = 0; counter < myform3.grp3.length; counter++) { if (myform3.grp3[counter].checked) radio_choice = true; } if (!radio_choice) { alert("Please select any one Answer"); return (false); } return(true); } </script> </head> <body> <h3>Quiz No.3</h3> Q3. What is the largest state in the USA<br><br> <form action="QuizPage4.jsp"method="post" name="myform" onsubmit="return check();"> <input type="radio" name="grp3" value="New York" >New York<br> <input type="radio" name="grp3" value="Alaska" >Alaska<br> <input type="radio" name="grp3" value="California" >California<br> <input type="radio" name="grp3" value="Melbourne" >Melbourne<br> <br><br><input type="submit" value="Next Question"> <input type="hidden" name="hidden" value="grp3"> <input type="submit" value ="Back" onclick="window.history.back();"/> </form> <% String s2=request.getParameter("grp2"); %> </body> </html>
QuizPage4.jsp
<html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <script language="JavaScript"> function check() { var radio_choice = false; for (counter = 0; counter < myform4.grp4.length; counter++) { if (myform4.grp4[counter].checked) radio_choice = true; } if (!radio_choice) { alert("Please select any one Answer"); return (false); } return(true); } </script> </head> <body> <h3>Quiz No.4</h3> Q4. The famous Dilwara Temples are situated in<br><br> <form action="QuizPage5.jsp"method="post" name="myform" onsubmit="return check();"> <input type="radio" name="grp4" value="Uttar Pradesh" >Uttar Pradesh<br> <input type="radio" name="grp4" value="Maharashtra" >Maharashtra<br> <input type="radio" name="grp4" value="Andhra Pradesh" >Andhra Pradesh<br> <input type="radio" name="grp4" value="Rajasthan" >Rajasthan<br> <br><br><input type="submit" value="Next Question"> <input type="hidden" name="hidden" value="grp4"> <input type="submit" value ="Back" onclick="window.history.back();"/> </form> <% String s3=request.getParameter("grp3"); %> </body> </html>
QuizPage5.jsp
<html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <script language="JavaScript"> function check() { var radio_choice = false; for (counter = 0; counter < myform5.grp5.length; counter++) { if (myform5.grp5[counter].checked) radio_choice = true; } if (!radio_choice) { alert("Please select any one Answer"); return (false); } return(true); } </script> </head> <body> <h3>Quiz No.5</h3> Q5. The Indian Institute of Science is located at<br><br> <form action="ResultPage.jsp"method="post" name="myform" onsubmit="return check();"> <input type="radio" name="grp5" value="Chennai" >Chennai<br> <input type="radio" name="grp5" value="Bangalore" >Bangalore<br> <input type="radio" name="grp5" value="Mumbai" >Mumbai<br> <input type="radio" name="grp5" value="Hyderabad" >Hyderabad<br> <br><br><input type="submit" value="Show Result"> <input type="hidden" name="hidden" value="grp5"/> </form> <% String s4=request.getParameter("grp4"); %> </body> </html>
ResultPage.jsp
<html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <title>Quiz Result</title> </head> <body> <% String answer="New Delhi"; String s1=request.getParameter("grp"); if(s1.equals(answer)) { out.println("Correct Answer"); } else {out.println("Wrong Answer! The Correct Answer is :"+answer); } %> <% String answer2="Tamilnadu"; String s2=request.getParameter("grp2"); if(s2.equals(answer2)) { out.println("Correct Answer"); } else {out.println("Wrong Answer! The Correct Answer is :"+answer2); } %> <% String answer3="Alaska"; String s3=request.getParameter("grp3"); if(s3.equals(answer3)) { out.println("Correct Answer"); } else {out.println("Wrong Answer! The Correct Answer is :"+answer3); } %> <% String answer4="Rajasthan"; String s4=request.getParameter("grp4"); if(s4.equals(answer4)) { out.println("Correct Answer"); } else {out.println("Wrong Answer! The Correct Answer is :"+answer4); } %> <% String answer5="Bangalore"; String s5=request.getParameter("grp5"); if(s5.equals(answer5)) { out.println("Correct Answer"); } else {out.println("Wrong Answer! The Correct Answer is :"+answer5); } %> </body> </html>
非常感谢您的帮助。提前致谢
如果您希望可以跨多个页面访问的数据，请考虑使用会话存储数据。例如，如果page1.jsp向page2.jsp提交了表单参数“ page1Result”，则在page2.jsp中，执行以下操作：
String page1Result = request.getParameter("page1Result"); request.getSession().setAttribute("page1Result", page1Result);
然后，在以后的某个时刻（例如第5页），您可以按以下方式访问page1值：
String page1Value = (String)request.getSession().getAttribute("page1Result);
================================================== =============================将其应用于您的代码：
在page2 jsp中，将文件末尾的scriptlet更改为：
<% String s1=request.getParameter("grp"); request.getSession().setAttribute("s1", s1); %>
在第3页JSP中，将脚本更改为：
<% String s2=request.getParameter("grp2"); request.getSession().setAttribute("s2", s2); %>
等等。
最后在ResultPage.jsp上（仅显示示例2）
out.println("Wrong Answer! The Correct Answer for question 2 is :"+session.getAttribute("s2"));
