clear form data

**acoder** · Jan 18 '09, 03:40 PM

You'll need to post your code, so that someone can see where you're going wrong.

Also, seeing as it's a JSP problem, I'm moving this thread to the Java forum.

**stack** · Jan 18 '09, 08:22 PM

index.jsp

Code:

<jsp:useBean id="bean" scope="session" class="myPack.bean" />
<%@page contentType="text/html" pageEncoding="UTF-8"%>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
   "http://www.w3.org/TR/html4/loose.dtd">
<% 
    if (request.getMethod().equalsIgnoreCase("POST")){
           bean.setP(request.getParameter("p"));
     }
%>
<html>
    <head>
        <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
        <title>JSP Page</title>
        
        <script language="javascript">
            function clearVars(url, popN){
                window.open(url, popN, "width=300, height=200, location=no,toolbar=no, scrollbars=no");
            }
        </script>
    </head>
    <body>
        <h2>form</h2>
      
        <form action="index.jsp" method="post">
            <input name="p" value="<% if(bean.getP() != null) out.print(bean.getP()); %>"/>
            <input type="submit" value="send form" />
        </form>
        
        <input type="button" value="clear all" onclick='clearVars("clearSession.jsp", "popup");' />
    </body>
</html>

clearSession.js p

Code:

<jsp:useBean id="bean" scope="session" class="myPack.bean" />
<%@page contentType="text/html" pageEncoding="UTF-8"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
   "http://www.w3.org/TR/html4/loose.dtd">

<% 
     bean.setP(null);  
 %>

<html>
    <head>
        <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
        <title>Reset Session</title>
        <script language="javascript">
            
            function refreshParent(){
                //close this popup
                window.close();
                // reload the parent
               window.opener.location.reload(true);
          }
        </script>
    </head>
    <body>
        <h4>All variables cleared from memory.<br> 
           Please press close to clear any old values </h4>
        <input type="button" value="close" onclick="refreshParent();">
  </body>
</html>

bean.java

Code:

package myPack;

public class bean {
    private String p;

    public String getP() {
        return p;
    }
    public void setP(String p) {
        this.p = p;
    }
}

thanks

**acoder** · Jan 19 '09, 08:42 AM

The problem is in refreshParent() where you have window.close before the parent reload - swap the two lines around.

PS. maybe I should've asked for the code before moving the thread. It seems it is a JavaScript problem, after all.

**stack** · Jan 19 '09, 06:21 PM

acoder thank you for your answer.

I tested what you said but that's not it. I still see the old information in my form (the reload() was working anyway). Maybe it is a JSP issue after all :-)
Any more suggestions?

thanks

**acoder** · Jan 20 '09, 01:43 PM

Aargh!

OK, when you reload the page, does it display a message about re-posting?

**stack** · Jan 20 '09, 06:55 PM

yes it does and I confirm to resend.

**acoder** · Jan 20 '09, 10:08 PM

That's the source of the problem. The values are reposted and in line 8, p is reset again to the posted value.

You can either use GET or use the Post-Redirect-Get pattern (see Post/Redirect/Get - Wikipedia, the free encyclopedia)

**stack** · Jan 21 '09, 06:57 PM

You were right. Fortunately the solution was much simpler.... Using a redirect the browser can reload a URL without repeating the original request (or at least this is what I understood by doing some googling)

So adding following code in line 9, solves the problem.

Code:

response.sendRedirect("index.jsp");

Thanks for all your help acoder!

**acoder** · Jan 21 '09, 07:24 PM

No problem at all. Glad you got it working :)

clear form data

clear form data

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