Java 使用case会话和form submit从一个servlet调用另一个servlet时获取null值
我有两个servlet 1）qz.java和2）logout.java我想从qz获得电子邮件以注销，这是我的实际问题 当我试图通过会话从登录页面到qz页面获取电子邮件时，它工作正常，但当我想从qz.java发送电子邮件到logout.java时，它会得到空值 然后我尝试不同的方法，添加代码，当我提交代码注销时，我收到的电子邮件字符串是s=request.getPrameter（“xyz”）；但是s返回空值。这个代码是测验应用程序，请给我正确的答案 这是我的代码…qz.ja的doget帖子Java 使用case会话和form submit从一个servlet调用另一个servlet时获取null值,java,html,servlets,Java,Html,Servlets,我有两个servlet 1）qz.java和2）logout.java我想从qz获得电子邮件以注销，这是我的实际问题 当我试图通过会话从登录页面到qz页面获取电子邮件时，它工作正常，但当我想从qz.java发送电子邮件到logout.java时，它会得到空值 然后我尝试不同的方法，添加代码，当我提交代码注销时，我收到的电子邮件字符串是s=request.getPrameter（“xyz”）；但是s返回空值。这个代码是测验应用程序，请给我正确的答案 这是我的代码…qz.ja的doget帖子 pro
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
//response.getWriter().append("Served at: ").append(request.getContextPath());
response.setContentType("text/html");
HttpSession session=request.getSession();
String val=(String) session.getAttribute("user1");
String val1=(String) session.getAttribute("email");
session.setAttribute("em", val1);
PrintWriter pr=response.getWriter();
String a="abcdefg";
if(val==null) {
response.sendRedirect("login.html");
}else {
//pr.println("");
RequestDispatcher rd=request.getRequestDispatcher("./timer");
rd.include(request, response);
pr.println("<!DOCTYPE html>\r\n" +
"<html>\r\n" +
"<head>\r\n" +
" <title></title>\r\n" +
" <!-- Latest compiled and minified CSS -->\r\n" +
"<link rel=\"stylesheet\" href=\"https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css\">\r\n" +
"\r\n" +
"<!-- jQuery library -->\r\n" +
"<script src=\"https://ajax.googleapis.com/ajax/libs/jquery/3.2.1/jquery.min.js\"></script>\r\n" +
"\r\n" +
"<!-- Latest compiled JavaScript -->\r\n" +
"<script src=\"https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/js/bootstrap.min.js\"></script>\r\n" +
"<script type=\"text/javascript\">\r\n" +
"var idleTime = 0;\r\n" +
"$(document).ready(function () {\r\n" +
" //Increment the idle time counter every minute.\r\n" +
" var idleInterval = setInterval(timerIncrement, 600); \r\n" +
"\r\n" +
" //Zero the idle timer on mouse movement.\r\n" +
" $(this).mousemove(function (e) {\r\n" +
" idleTime = 0;\r\n" +
" });\r\n" +
" $(this).keypress(function (e) {\r\n" +
" idleTime = 0;\r\n" +
" });\r\n" +
"});\r\n" +
"\r\n" +
"function timerIncrement() {\r\n" +
" idleTime = idleTime + 1;\r\n" +
" if (idleTime > 6) { \r\n" +
" window.location.href=\"login.html\";\r\n" +
" }\r\n" +
"}\r\n" +
"</script>"+
"</head>\r\n" +
"<body>\r\n" +
"<div id=\"u\" name=\"usern\">\r\n" +
"\r\n" + "Welcome :"+val+
" </div>"+
"<form action=\"logout\" id=\"logsub\">\r\n" +
"<div class=\"container\">\r\n" + "<div name=\"email\" value=\"tofik@gmail.com\">\r\n" +
" \r\n" +
"</div>\r\n" +
""+
"<label id=\"e\" name=\"abc\" value=\"abc\"> abc : </label>\r\n" +
" <div class=\"row\">\r\n" +
" <!-- Carousel -->\r\n" +
" <div id=\"carousel-example-generic\" class=\"carousel slide\">\r\n" +
" <!-- Indicators -->\r\n" +
" \r\n" +
" <!-- Wrapper for slides -->\r\n" +
" <div class=\"carousel-inner\">\r\n" +
" <div class=\"item active\">\r\n" +
" <!img src=\"http://unsplash.s3.amazonaws.com/batch%209/barcelona-boardwalk.jpg\" alt=\"First slide\">\r\n" +
" <!-- Static Header -->\r\n" +
" <div class=\"header-text hidden-xs\">\r\n" +
" <div class=\"col-md-12 text-center\">\r\n" +
" <div class=\"container\">\r\n" +
"<div class=\"col-sm-6\" style=\"margin-left:250px;margin-top:150px\">\r\n" +
"\r\n" +
"\r\n" +
"<div style=\"border:2px solid black;padding:10px;margin-top:20px\">\r\n" +
" <h4 >What is 1+1 ?</h4>\r\n" +
"\r\n" +
"\r\n" +
" \r\n" +
" \r\n" +
"\r\n" +
" \r\n" +
" \r\n" +
" <input type=\"radio\" name=\"ans1\" value=\"1\" >A : 1\r\n" +
"\r\n" +
" <br>\r\n" +
"\r\n" +
" <input type=\"radio\" name=\"ans1\" value=\"2\" >B : 2\r\n" +
"\r\n" +
" <br>\r\n" +
"\r\n" +
" <input type=\"radio\" name=\"ans1\" value=\"4\" >C : 4\r\n" +
"\r\n" +
" <br>\r\n" +
"\r\n" +
" \r\n" +
" \r\n" +
" \r\n" +
" <input type=\"radio\" name=\"ans1\" value=\"3\" >D : 3\r\n" +
" <br>\r\n" +
" <br>\r\n" +
"\r\n" +
" \r\n" +
" \r\n" +
" \r\n" +
" \r\n" +
" \r\n" +
"</div>\r\n" +
" \r\n" +
" </div> \r\n" +
"</div>\r\n" +
"\r\n" +
" </div>\r\n" +
" </div><!-- /header-text -->\r\n" +
" </div>\r\n" +
" <div class=\"item\">\r\n" +
" <!img src=\"http://unsplash.s3.amazonaws.com/batch%209/barcelona-boardwalk.jpg\" alt=\"Second slide\">\r\n" +
" <!-- Static Header -->\r\n" +
" <div class=\"header-text hidden-xs\">\r\n" +
" <div class=\"col-md-12 text-center\">\r\n" +
" <div class=\"container\">\r\n" +
"<div class=\"col-sm-6\" style=\"margin-left:250px;margin-top:150px\">\r\n" +
"\r\n" +
"\r\n" +
"<div style=\"border:2px solid black;padding:10px;margin-top:20px\">\r\n" +
" <h4 >What is 4/2 ?</h4>\r\n" +
"\r\n" +
"\r\n" +
" \r\n" +
" \r\n" +
"\r\n" +
" \r\n" +
" \r\n" +
" <input type=\"radio\" name=\"ans2\" value=\"3\" >A : 3\r\n" +
"\r\n" +
" <br>\r\n" +
"\r\n" +
" <input type=\"radio\" name=\"ans2\" value=\"5\" >B : 5\r\n" +
"\r\n" +
" <br>\r\n" +
"\r\n" +
" <input type=\"radio\" name=\"ans2\" value=\"2\" >C : 2\r\n" +
"\r\n" +
" <br>\r\n" +
"\r\n" +
" \r\n" +
" \r\n" +
" \r\n" +
" <input type=\"radio\" name=\"ans2\" value=\"6\" >D : 6\r\n" +
" <br>\r\n" +
" <br>\r\n" +
"\r\n" +
" \r\n" +
" \r\n" +
" \r\n" +
" \r\n" +
" \r\n" +
"</div>\r\n" +
" \r\n" +
" </div> \r\n" +
"</div>\r\n" +
"\r\n" +
" </div>\r\n" +
" </div><!-- /header-text -->\r\n" +
" </div>\r\n" +
"\r\n" +
" <div class=\"item\">\r\n" +
" <!img src=\"http://unsplash.s3.amazonaws.com/batch%209/barcelona-boardwalk.jpg\" alt=\"Second slide\">\r\n" +
" <!-- Static Header -->\r\n" +
" <div class=\"header-text hidden-xs\">\r\n" +
" <div class=\"col-md-12 text-center\">\r\n" +
" <div class=\"container\">\r\n" +
"<div class=\"col-sm-6\" style=\"margin-left:250px;margin-top:150px\">\r\n" +
"\r\n" +
"\r\n" +
"<div style=\"border:2px solid black;padding:10px;margin-top:20px\">\r\n" +
" <h4 >What is 5*2*1 ?</h4>\r\n" +
"\r\n" +
"\r\n" +
" \r\n" +
" \r\n" +
"\r\n" +
" \r\n" +
" \r\n" +
" <input type=\"radio\" name=\"ans3\" value=\"11\" >A : 11\r\n" +
"\r\n" +
" <br>\r\n" +
"\r\n" +
" <input type=\"radio\" name=\"ans3\" value=\"3\" >B : 3\r\n" +
"\r\n" +
" <br>\r\n" +
"\r\n" +
" <input type=\"radio\" name=\"ans3\" value=\"2\" >C : 2\r\n" +
"\r\n" +
" <br>\r\n" +
" \r\n" +
" \r\n" +
" <input type=\"radio\" name=\"ans3\" value=\"10\" >D : 10\r\n" +
" <br>\r\n" +
" <br>\r\n" +
"\r\n" +
" \r\n" +
" \r\n" +
" \r\n" +
"</div>\r\n" +
" \r\n" +
" </div> \r\n" +
"</div>\r\n" +
"\r\n" +
" </div>\r\n" +
" </div><!-- /header-text -->\r\n" +
" </div>\r\n" +
"\r\n" +
"\r\n" +
" <div class=\"item\">\r\n" +
" <!img src=\"http://unsplash.s3.amazonaws.com/batch%209/barcelona-boardwalk.jpg\" alt=\"Third slide\">\r\n" +
" <!-- Static Header -->\r\n" +
" <div class=\"header-text hidden-xs\">\r\n" +
" <div class=\"col-md-12 text-center\">\r\n" +
" <div class=\"container\">\r\n" +
"<div class=\"col-sm-6\" style=\"margin-left:250px;margin-top:150px\">\r\n" +
"\r\n" +
"\r\n" +
"<div style=\"border:2px solid black;padding:10px;margin-top:20px\">\r\n" +
" \r\n" +
"\r\n" +
"\r\n" +
" \r\n" +
" \r\n" +
"\r\n" +
" \r\n" +
" \r\n" +
" \r\n" +
"\r\n" +
"<label id=\"e\" name=\"email\"> Mail ID :"+val1+" </label>"+
" <input type=\"submit\" name=\"submit1\" value=\"submit\" class=\"btn btn-primary\">\r\n" +
" \r\n" +
" \r\n" +
" \r\n" +
" \r\n" +
"</div>\r\n" +
" \r\n" +
" </div> \r\n" +
"</div>\r\n" +
"\r\n" +
" </div>\r\n" +
" </div><!-- /header-text -->\r\n" +
" </div>\r\n" +
" </div>\r\n" +
" <!-- Controls -->\r\n" +
" <a class=\"left carousel-control\" href=\"#carousel-example-generic\" data-slide=\"prev\">\r\n" +
" <span class=\"glyphicon glyphicon-chevron-left\"></span>\r\n" +
" </a>\r\n" +
" <a class=\"right carousel-control\" href=\"#carousel-example-generic\" data-slide=\"next\">\r\n" +
" <span class=\"glyphicon glyphicon-chevron-right\"></span>\r\n" +
" </a>\r\n" +
" </div><!-- /carousel -->\r\n" +
" </div>\r\n" +
"</div>\r\n" +
"\r\n" +
"</form>\r\n" +
"\r\n" +
"</body>\r\n" +
"</html>");
}
}
/**
* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
*/
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
//
//doGet(request, response);
}
受保护的void doGet（HttpServletRequest请求，HttpServletResponse响应）抛出ServletException，IOException{
//TODO自动生成的方法存根
//response.getWriter（）.append（“服务于：”）.append（request.getContextPath（））；
response.setContentType（“text/html”）；
HttpSession session=request.getSession（）；
String val=（String）session.getAttribute（“user1”）；
String val1=（String）session.getAttribute（“电子邮件”）；
session.setAttribute（“em”，val1）；
PrintWriter pr=response.getWriter（）；
字符串a=“abcdefg”；
if（val==null）{
sendRedirect（“login.html”）；
}否则{
//pr.println（“”）；
RequestDispatcher rd=request.getRequestDispatcher（“./timer”）；
包括（请求、响应）；
pr.println（“\r\n”+
“\r\n”+
“\r\n”+
“\r\n”+
“\r\n”+
“\r\n”+
“\r\n”+
“\r\n”+
“\r\n”+
“\r\n”+
“\r\n”+
“\r\n”+
“\r\n”+
“var idleTime=0；\r\n”+
“$（文档）.ready（函数（）{\r\n”+
“//每分钟递增一次空闲时间计数器。\r\n”+
“var idleInterval=setInterval（timerIncrement，600）；\r\n”+
“\r\n”+
“//在鼠标移动时将空闲计时器归零。\r\n”+
“$（this）.mousemove（函数（e）{\r\n”+
“idleTime=0；\r\n”+
“}）；\r\n”+
“$（this）.keypress（函数（e）{\r\n”+
“idleTime=0；\r\n”+
“}）；\r\n”+
“}）；\r\n”+
“\r\n”+
“函数timerIncrement（）{\r\n”+
“idleTime=idleTime+1；\r\n”+
“如果（空闲时间>6）{\r\n”+
“window.location.href=\”login.html\“；\r\n”+
“}\r\n”+
“}\r\n”+
""+
“\r\n”+
“\r\n”+
“\r\n”+
“\r\n”+”欢迎：“+val”+
" "+
“\r\n”+
“\r\n”+“\r\n”+
“\r\n”+
“\r\n”+
""+
“abc:\r\n”+
“\r\n”+
“\r\n”+
“\r\n”+
“\r\n”+
“\r\n”+
“\r\n”+
“\r\n”+
“\r\n”+
“\r\n”+
“\r\n”+
“\r\n”+
“\r\n”+
“\r\n”+
“\r\n”+
“\r\n”+
“\r\n”+
“\r\n”+
“什么是1+1？\r\n”+
“\r\n”+
“\r\n”+
“\r\n”+
“\r\n”+
“\r\n”+
“\r\n”+
“\r\n”+
“A:1\r\n”+
“\r\n”+
“
\r\n”+
“\r\n”+
“B:2\r\n”+
“\r\n”+
“
\r\n”+
“\r\n”+
“C:4\r\n”+
“\r\n”+
“
\r\n”+
“\r\n”+
“\r\n”+
“\r\n”+
“\r\n”+
“D:3\r\n”+
“
\r\n”+
“
\r\n”+
“\r\n”+
“\r\n”+
“\r\n”+
“\r\n”+
“\r\n”+
“\r\n”+
“\r\n”+
“\r\n”+
“\r\n”+
“\r\n”+
“\r\n”+
“\r\n”+
“\r\n”+
“\r\n”+
“\r\n”+
“\r\n”+
“\r\n”+
“\r\n”+
“\r\n”+
“\r\n”+
“\r\n”+
“\r\n”+
“\r\n”+
“\r\n”+
“什么是4/2？\r\n”+
“\r\n”+
“\r\n”+
“\r\n”+
“\r\n”+
“\r\n”+
“\r\n”+
"
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
//HttpSession session=request.getSession();
//session.invalidate();
response.setContentType("text/html");
HttpSession session=request.getSession();
//String s=(String) ses.getAttribute("email");
PrintWriter pr1 = response.getWriter();
String ans1=request.getParameter("ans1");
String ans2=request.getParameter("ans2");
String ans3=request.getParameter("ans3");
String emailid=request.getParameter("email");
String abc=request.getParameter("abc");
System.out.println(emailid);
//int a11=0;
System.out.println(ans1);
//pr1.println(s);
int score=0;
String a1="2",a2="2",a3="10";
if(ans1.equals(a1)) {
score=score+1;
System.out.println("incremented");
}
if(ans2.equals(a2)) {
score=score+1;
System.out.println("incremented");
}
if(ans3.equals(a3)) {
score=score+1;
System.out.println("incremented");
}
String mar=""+score;
//ses.setAttribute("marks", mar);
doPost(request, response);
pr1.println("<!DOCTYPE html>\r\n" +
"<html>\r\n" +
"<head>\r\n" +
" <title></title>\r\n" +
"\r\n" +
" <link rel=\"stylesheet\" href=\"https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css\">\r\n" +
"\r\n" +
"<!-- jQuery library -->\r\n" +
"<script src=\"https://ajax.googleapis.com/ajax/libs/jquery/3.2.1/jquery.min.js\"></script>\r\n" +
"\r\n" +
"<!-- Latest compiled JavaScript -->\r\n" +
"<script src=\"https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/js/bootstrap.min.js\"></script>\r\n" +
"\r\n" +
"\r\n" +
" <script>\r\n" +
"window.onload = function (){ UrFunction(); }\r\n" +
"\r\n" +
"function UrFunction()\r\n" +
"{\r\n" +
" var x;\r\n" +
" var r=confirm(\"Your Score is :"+mar+"\");\r\n" +
" if (r==true)\r\n" +
" {\r\n" +
//" confirm(\"Wanna change Password?\");s\r\n" +
" window.location.assign(\"login.html\")\r\n" +
" }\r\n" +
" else\r\n" +
" {\r\n" +
" x=\"You pressed Cancel!\";\r\n" +
"\r\n" +
" }\r\n" +
" \r\n" +
"}\r\n" +
"</script>"+
"\r\n" +
"</head>\r\n" +
"<body>\r\n" +
" \r\n" +
""+
"\r\n" +
"</body>\r\n" +
"</html>\r\n" +
"\r\n" +
"\r\n" +
"");
//ans1=""; ans2=""; ans3=""; score=0;
//response.sendRedirect("login.html");
}
/**
* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
*/
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
//doGet(request, response);
HttpSession session=request.getSession();
String s1=(String) session.getAttribute("em");
System.out.println("Email="+s1);
}
//pr.println("");
RequestDispatcher rd=request.getRequestDispatcher("./timer");
rd.include(request, response);
pr.println("<!DOCTYPE html>\r\n" +
"<html>\r\n" +
"<head>\r\n" +
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
HttpSession session=request.getSession();
String val=(String) session.getAttribute("user1");
String val1=(String) session.getAttribute("email");
session.setAttribute("em", val1);
PrintWriter pr=response.getWriter();
String a="abcdefg";
if(val==null) {
RequestDispatcher rd=request.getRequestDispatcher("login.html");
rd.forward(request,response);
return;
}else {
RequestDispatcher rd=request.getRequestDispatcher("somethingElse.html");
rd.forward(request,response);
}
}