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How to maintain the contents in the text field after redircting to same page jsp.

Hi I have jsp page That is having some text fields,I will fill that text fields and I will submit that form to server side.If any error comes in the server side I will redirect to the same page with error message Now I want that text field to remain as it is but in my case it is clearing.How to make the text field as same.

The two options available to you are:
Don't reload the page. Instead submit the data via AJAX or validate it by javascript. That way you don't ever have to touch the data in the form. Make sure your javascript highlights the fields that have errors in some way.
The endpoint that you're POSTing your data to needs to be able to recognise that the data is invalid and include that data when returning the user to the same page. I'm not familiar with jsp, but generally you'd do that by including variables in your template for your form that could contain the data, and passing empty strings on the first load of the page. If the page is then shown to the user again after a failed form validation, pass back the POST data that you received in your form request.

There are two option, you can dispatch the request/response to the same page instead of redirect, but you need to add an attribute and recover it in the JSP, or you can add the attribute in the session , recover the value to de text field and remove it using (if you are using JSTL)

Forwarding the request from one jsp to another jsp with all request parameters?

i have this scenario. User enter some stuff on jsp form in browser and submit. In servlet i process the request and show the jsp page1 to client which has just continue
button. Now on click of continue, i want to forward this request to another jsp page2 with all request parameter present on page1. basically i want to get all request parameters which were present in first request on page 2 also? I am not getting how should i go
for this? I dont think i can use jsp forward as per my understanding it would work only when both when we want to forward from jsp (on server side) not on client side?

There are two ways to implement that:
output all parameters in hidden fields, and submit them in the 2nd request
store everything in the session

Following are a pair of ways to achieve this
Put the information in session object in first request and access it from session object in second.
On the intermediate page displayed, have hidden form elements which will carry the values and send it back on continuing.

You can use Servlet Forward to pass all request parameters to another JSP or Servlet:
getServletContext().getRequestDispatcher("/yourJSP.jsp").forward(request, response);
Servlet forward will forward the existing request to another JSP or Servlet, so all the request parameters and attributes will be available to the destination JSP or Servlet (The reason you can use the Servlet forward is that JSP is also a Servlet after translation).
You may find following resources useful:
Pass data from servlet to jsp
Servlet Redirect vs Forward

Pass parameters from one jsp to another using post method

I want to pass parameters from one jsp to another.
I have tried using the post method, <jsp:forward/>, but it doesn't work.
I have created a <form> in html (parameters passed using POST), which is submitted to a servlet which processes the request and forwards it to another servlet that displays a page.
From this servlet i have created links to another jsp, passing through the parameters as GETs in the URL. However, I actually want to pass the parameters to another jsp using POST, and then pass it on to another jsp.
What solutions do you have or this problem?

Check out the Request Dispatcher. You need to forward the request to the landing JSP.
http://docs.oracle.com/javaee/6/api/javax/servlet/RequestDispatcher.html

Sounds like you are creating a multipage form that gathers information from the user across several distinct pages. In that case one option is to use hidden fields on a form to store the previous values. This of course means that as the pages progress the amount of data passing back and forth from client to server increases.
You may consider a server side approach by storing the interim values in a database for instance, then only passing a token back to the client. When the next JSP page is submitted, use the token to look up the values in the database.

JSP has built-in request object.when one jsp redirect to another jsp with some parameter, you can get parameter value using this request object.
<%
String param1 = request.getParameter("parameter_name");
%>
you can find example here -
http://www.roseindia.net/jsp/RequestObjectInJSP.shtml

Why don't you call a page on the click of a submit button by creating
an url in the below format (in javascript):- var
url="your_page_name.jsp?value1="+encodeURIComponent(document.getElementById("your_text_field_or_any_other_field_id"));
and then call the page by using your url
document.your_form_name.action=url;
document.your_form_name.submit();
and then use request.getParameter() method either in servlet
or in the jsp that u'v metioned in the url (servlet or the jsp u'll be
calling thorugh u'r jsp).

How to change url in user browser without client redirect in servlet

I want to forward from one page to another but with the same I want url to be changed. Suppose user is here http://mywebsite/register and when he completes his registration process then I want this in his address bar http://mywebsite/home
Is it possible without using sendRedirect , I mean by the way server side forwarding only? or any other way around to this problem?

You could just let the HTML form submit to that URL directly.
<form action="http://mywebsite/home">
But this makes no sense. You'll also run into problems when redisplaying the same form with validation messages in case of validation failure. You'd need to redirect back to the original page if you intend to keep the original URL and you'd need to fiddle with storing messages in the session scope instead of the request scope because a redirect basically creates a brand new request. You'll without a redirect also run in "double submit" problem whenever the enduser presses F5 after submitting the form.
Just let the servlet redirect the successful POST request to the desired URL. That's the canonical approach. Even more, this is a recommend "design pattern": the POST-Redirect-GET pattern.

AFAIK there's no way around a redirect since the browser has to update the url at some point. And if you'd update the url after the forwarded to page has been loaded it would issue a refresh and the page would be loaded again (which might result in an endless loop).
Why don't you want to use a redirect in that case?

Various Questions about JSF

i'm doing a JSF2 project.
1 . i have a form with some checkbox. Look the following code
<ui:repeat>
<h:selectManyCheckbox value="#{wagent.selectedPra}">...
</h:selectManyCheckbox>
</ui:repeat>
So i use selectManyCheckbox inside ui:repeat and i want that the value of the different selectManyCheckbox point to the same value.
But when the form is submit i didn't have all the selected boxs.
How i can do that ?
2 . I have a form with some inputs. On my action i want to merge some pdf files, stay on the same page and that a pop-up appear to offer to download the merged files.
3 . Does all the managed beans with request scope are created for each request or just if i used them in the xhtml page?
4 . I have a commandlink to logout. On my action i use session.invalidate() and return "login". So i go back to the login, but when validating the login, my session managed bean doesn't seem to be created. Error is something like yourSessionBean is null. What's wrong ?

1: So i use selectManyCheckbox inside ui:repeat and i want that the value of the different selectManyCheckbox point to the same value. But when the form is submit i didn't have all the selected boxs. How i can do that ?
Let them point to a different value instead. With the given example the bean value will be overridden everytime until end of the loop. As an example, use a List<List<Pra>> in a bean (or whatever Pra means in your question):
<ui:repeat value="#{wagent.allSelectedPra}" var="selectedPra">
<h:selectManyCheckbox value="#{selectedPra}">
...
</h:selectManyCheckbox>
</ui:repeat>
2: I have a form with some inputs. On my action i want to merge some pdf files, stay on the same page and that a pop-up appear to offer to download the merged files.
At least two things needs to be done:
facesContext.getExternalContext().addResponseHeader("Content-Disposition", "attachment;filename=name.pdf"); // Force "Save As" dialogue.
facesContext.responseComplete(); // Prevent JSF from taking response in hands.
3: Does all the managed beans with request scope are created for each request or just if i used them in the xhtml page?
They are created for every HTTP request. The scope which you described only applies on view scope (if I understand you right).
4: I have a commandlink to logout. On my action i use session.invalidate() and return "login". So i go back to the login, but when validating the login, my session managed bean doesn't seem to be created. Error is something like yourSessionBean is null. What's wrong ?
You are probably accessing the session scoped managed bean the wrong way. You need to either inject it as #ManagedProperty or to grab it by Application#evaluateExpressionGet().