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How to invoke a method when back button in browser is clicked.

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posted 16 years ago

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Hi All,
I wanted to know how can we make it possible so that if a user clicks on the back button on the browser he should be redirected/forwarded to an error page or may be a session expired page (if he uses back after signing out)?
-Regards
Prakash
[ October 15, 2007: Message edited by: prakashSchauhan ]

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posted 16 years ago

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"prakashSchauhan", please check your private messages for an important message from me.

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Amol Nayak

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posted 16 years ago

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You will have to prevent caching on client browser.

You can use this code to do that

prakash chauhan

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posted 16 years ago

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hey Anmol Thanks for the quick reply.

-Regards

prakash chauhan

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on which page do we have to do the disabling of the Cache?
if the flow is from A.jsp->B.jsp then on which page do i need to write that code? B.jsp?
-Thanks.

Amol Nayak

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The page which you dont want to cache, since you dont want to come to a.jsp on click of the back button without sending a new request to server, you need set these headers with the response of a.jsp.

prakash chauhan

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posted 16 years ago

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okay what i have here is AddEmployee.jsp , its submit button invokes a servlet which forwards (Requestdispatcher) to another Result.jsp page.
I initially added the code you sent to the AddEmployeeServlet which made my Result.jsp page "cache-Disabled" i can not go back to the Result page but i could still go back to the AddEmployee.jsp page.
Then i added the same code in my AddEmplyee.jsp (as scriplet ) but still i am not able to make my addEmployee.jsp page "cached-disabled" ,
is the intermediate Sevlet causing any problem?

-Thanks.

Amol Nayak

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posted 16 years ago

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Can you post your code as well explaining what you tried? post the two jsps and the servlet. It would be much easy to help you out. Its important where you are setting those headers in the jsp, it should not be done once response is committed.
Also you need to follow a naming convention here on javaranch, did you check the private message from Bear?

Ben Souther

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posted 16 years ago

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"prakashSchauhan",
It is important that you check your private messages and follow the instructions given by Bear Bibeault.

Thank you
-Ben

Java API J2EE API Servlet Spec JSP Spec How to ask a question... Simple Servlet Examples jsonf

Bear Bibeault

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posted 16 years ago

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Indeed, please check your private messages again.

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prakash chauhan

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posted 16 years ago

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The code for first page:
--------------------------

<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
    pageEncoding="ISO-8859-1"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>Add New Employee</title>
</head>
 
<body background="image307.gif">
<-- THIS IS THE PLACE I PLACED YOUR CODE-->
<%response.setHeader("Cache-Control","no-cache"); response.setHeader("Pragma","no-cache"); response.setDateHeader ("Expires", 0);%>
 
<form action="AddEmployee" method="post">
<center>
<h1>ADD NEW EMPLOYEE</h1>
<HR>
<table bordercolor="yellow" border="0">
<tr>
<td align="right">First Name</td>
<td align="left"><input type="text" name="firstName"/></td>
</tr>
<tr>
<td align="right">Last Name</td>
<td align="left"><input type="text" name="lastName"/></td>
</tr>
<tr background="1">
<td align="right">UserID</td>
<td align="left"><input type="text" name="ID"/></td>
</tr>
<tr>
<td align="right">Manager's ID</td>
<td align="left"><input type="text" name="manager"/></td>
</tr>
<tr>
<td align="right">Birthday</td>
<td align="left"><input type="text" name="dateOfBirth"/></td>
</tr>
<tr>
<td align="right">Address</td>
<td align="left"><input type="text" name="address"/></td>
</tr>
<tr>
<td align="right"><input type="submit" value="SUBMIT"/></td>
<td align="left"><input type="reset" value="CLEAR"/></td>
</tr>
 </table>
 <hr>
 <br>
</body>
</html>

--------------------------

After this i have a servlet , which just takes up the parametes and adds it to the database and then goes to the next Result page
-----------------------------------------------------------------------
this is the servlet code:

______________________________________________________________________
This is result.jsp

----------------------------------------------------
Wht is wrong here?
-Thanks

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[ October 18, 2007: Message edited by: Ben Souther ]

prakash chauhan

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posted 16 years ago

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any suggestions??
-Thanks

Ben Souther

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posted 16 years ago

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The server has no way of knowing if a request was triggered by the back button.

Look into the Post-Redirect-Get pattern to help with this problem.
There is an example in our JSP FAQ page.

Java API J2EE API Servlet Spec JSP Spec How to ask a question... Simple Servlet Examples jsonf