Udayaditya Barua

Originally posted by William Brogden:
I see code like:

sess.setAttribute("correctCount", correctScoreArray);

but it looks like correctScoreArray is an instance variable and is thus used for all requests. It is always there and does not need to be put in the user's session.

I see local variable creation like:

Integer[] getCorrectScoreSessVar = (Integer[]) sess.getAttribute("correctCount")
but I dont understand what you are trying to do with it.

Bill

getCorrectScoreSessVar is the variable used to collect the value of the session. I am incrementing that and storing the new value in the session. I've removed the correctScoreArray usage in the code. Just trying to implement multiple counters based on the option(if else). Can you tell me a better way to do it?
[ December 21, 2008: Message edited by: Udayaditya Barua ]

My apologies.

hi,
I have a website which is a maths tutorial. In short, there are addition,subtraction,multiply and division. One servlet generates a problem and sends it to the client.Now, when the user enters the answer another ajax request is sent to a different servlet. This servlet, maintains the score for CORRECT answers and WRONG answers in sessions. I though it wud be better to create an array for CORRECT and WRONG since, there will be too many variables each for correct/wrong addition,subtraction etc.
I have 2 arrays: /** * @Array correctScoreArray: 0->Add 1->Subtract 2->multiply 3->Division * @Array wrongScore: 0->Add 1->Subtract 2->multiply 3->Division */ public int[] correctScoreArray = new int[4]; public int[] wrongScore = new int[4];
I am storing these arrays in sessions. heres the rest of the code..
try { HttpSession sess = request.getSession(false); Integer[] getCorrectScoreSessVar = (Integer[]) sess.getAttribute("correctCount"); Integer[] getWrongScoreSessVar = (Integer[]) sess.getAttribute("wrongCount"); int temp = 0; int temp2 = 0; int option = Integer.parseInt(request.getParameter("option")); if (option == 1) { //Addition if (ansType.equals("c")) //If answer is correct, update the correct { // score Session variable if (getCorrectScoreSessVar == null) { temp = new Integer(1); } else { temp = new Integer(getCorrectScoreSessVar[0].intValue() + 1); correctScoreArray[0] = temp; } sess.setAttribute("correctCount", correctScoreArray); out.println(temp); } else //Update the wrong score variable { if (getWrongScoreSessVar == null) { temp2 = new Integer(1); } else { temp2 = new Integer(getWrongScoreSessVar[0].intValue() + 1); wrongScore[0] = temp2; } sess.setAttribute("wrongCount", wrongScore); out.println(wrongScore[0]); } }
Similarly for subtraction,mul,div. The problem is, the values dont get added!. I WANT them to be replaced with the new ADDED values. Like a counter.. Can anyone help me out??

Originally posted by David McHugh:
[QB

String filename = "C:/Java/jakarta-tomcat-5.0.28/webapps/text.txt"; [/QB]

Correct me if i m wrong, if this is a windows system, filename path should have backslashes instead of forward.So
String filename = "C:\Java\jakarta-tomcat-5.0.28\webapps\text.txt";

Same as above except you can also try

if(request.getAttribute("error_message") != null) { <div id='result' ><%=request.getAttribute("error_message")%></div> } else { <div id='result' > </div> }

For future ref you might consider:
http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html

@shekhar
thanks

Ok, sry for the delay.. Managed to solve the problem after a lot of searching... Had to write a 'return' after the forward command..
About the switch case executing every statement, doesnt writing a "break" solve that?..Just asking..

Hi, im kind of new to servlets. i have a servlet which accepts data from a HTML form. Basically 2 numbers, according to the option chosen, their addition,multiply etc. User enters the answer, servlet checks whether it was correct or not. If wrong, shows solution.
processRequest() is the function which is called by doPost. It calls processAnswer() which basically does the forwarding of the page according to the answer.
Heres processRequest
protected void processRequest(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { response.setContentType("text/html;charset=UTF-8"); //PrintWriter out = response.getWriter(); int answer = 0; int number1 = 0; int number2 = 0; int opt = 0; /*various getRequestParameters...*/ try { /*Converting strings to integers (parseInt)....*/ } catch (NumberFormatException nfe) { //In case user entered anything else other dan a number String display = "<HTML><BODY>" + "<h3>YOU ARE SUPPOSED TO ENTER A NUMBER!</h3>" + "</BODY></HTML>"; request.setAttribute("result", display); getServletContext().getRequestDispatcher("/levelone.jsp").forward(request, response); } processAnswer(answer, opt, number1, number2, request, response); }
WHICH CALLS processAnswer()
public void processAnswer(int answer, int option, int num1, int num2, HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { response.setContentType("text/html;charset=UTF-8"); switch (option) { case 1: { int temp = num1 + num2;//Addition if (answer == temp) { String display = "<HTML><BODY>" + "<h3>Your answer is correct! </h3>" + "</BODY></HTML>"; request.setAttribute("result", display); getServletContext().getRequestDispatcher("/levelone.jsp").forward(request, response); } else { String display = generateAnswer(num1, num2, '+',temp); //THIS RETURNS JUST A STRING request.setAttribute("result", display); getServletContext().getRequestDispatcher("/levelone.jsp").forward(request, response); } } case 2: { int temp = num1 - num2; //Subtraction if (answer == temp) { String display = "<HTML><BODY>" + "<h3>Your answer is correct! </h3>" + "</BODY></HTML>"; request.setAttribute("result", display); getServletContext().getRequestDispatcher("/levelone.jsp").forward(request, response); } else { String display = generateAnswer(num1, num2, '-',temp); request.setAttribute("result", display); getServletContext().getRequestDispatcher("/levelone.jsp").forward(request, response); } } } }
Really need help here..I tried adding a "return" in processRequest, didnt help.