Re: NullpointerException when closing folder

Hi Bill!

Now I saw what the problem is: in principle there is only one
possibility to cause a NullPointerException => if you run out of memory.
And exactly that happend. The reason why I don't figured it out earlier
is because I don't checked the catalina.out file of Tomcat. Anyway, I
corrected now my source code in the way, that I transfer smaller chunks
of data.

Sincerely,
Wolfgang


On Fri, 2009-03-20 at 11:39 -0700, Bill Shannon wrote:
> Wolfgang Beikircher wrote:
> > Hi there!
> > 
> > I'm using JavaMail 1.4.2 and get an NullPointerException when I try to
> > close a folder. This happens only after some hours of run time of my
> > application. Therefore, I think it has something to do with the
> > connection timeout to the server. 
> > 
> > This is the error stack:
> > 
> > Caused by: java.lang.NullPointerException
> >     at com.sun.mail.iap.Protocol.command(Protocol.java:324)
> >     at
> > com.sun.mail.imap.protocol.IMAPProtocol.logout(IMAPProtocol.java:311)
> >     at com.sun.mail.imap.IMAPStore.releaseProtocol(IMAPStore.java:944)
> >     at com.sun.mail.imap.IMAPFolder.releaseProtocol(IMAPFolder.java:2666)
> >     at com.sun.mail.imap.IMAPFolder.cleanup(IMAPFolder.java:1143)
> >     at com.sun.mail.imap.IMAPFolder.close(IMAPFolder.java:1132)
> >     at com.sun.mail.imap.IMAPFolder.close(IMAPFolder.java:1055)
> >     at com.sun.mail.imap.IMAPStore.cleanup(IMAPStore.java:1289)
> >     at com.sun.mail.imap.IMAPStore.handleResponse(IMAPStore.java:1509)
> >     at com.sun.mail.iap.Protocol.notifyResponseHandlers(Protocol.java:216)
> >     at
> > com.sun.mail.imap.protocol.IMAPProtocol.logout(IMAPProtocol.java:316)
> >     at com.sun.mail.imap.IMAPStore.close(IMAPStore.java:1217)
> >     at
> > org.zimbra.exchange.email.transport.ImapMailServerWrapper.releaseConnection(ImapMailServerWrapper.java:129)
> >     ... 7 more
> 
> You may be right about a timeout causing this problem, but I'm
> struggling to see why a timeout would cause this NullPointerException.
> 
> The code in Protocol.java is:
> 
>      public synchronized Response[] command(String command, Argument args) {
>       Vector v = new Vector();
>       boolean done = false;
>       String tag = null;
>       Response r = null;
> 
>       // write the command
>       try {
>              tag = writeCommand(command, args);
>       } catch (LiteralException lex) {
>              v.addElement(lex.getResponse());
>              done = true;
>       } catch (Exception ex) {
>              // Convert this into a BYE response
>              v.addElement(Response.byeResponse(ex));
>              done = true;
>       }
> 
>          while (!done) {
>              try {
>                  r = readResponse();
>              } catch (IOException ioex) {
>               // convert this into a BYE response
>               r = Response.byeResponse(ioex);
>              } catch (ProtocolException pex) {
>               continue; // skip this response
>              }
> 
>              v.addElement(r);
> 
>              if (r.isBYE()) // shouldn't wait for command completion response
>               done = true;
> 
>              // If this is a matching command completion response, we are done
>              if (r.isTagged() && r.getTag().equals(tag))
>               done = true;
>       }
> 
>          Response[] responses = new Response[v.size()];
>       v.copyInto(responses);                          // <---- line 324
>       timestamp = System.currentTimeMillis();
>       return responses;
>      }
> 
> "v" can't be null.  "responses" can't be null.
> Even if one of the elements in v is null (which shouldn't happen),
> that wouldn't cause the NullPointerException.
> 
> What am I missing?
> 
> ===========================================================================
> To unsubscribe, send email to [EMAIL PROTECTED] and include in the body
> of the message "signoff JAVAMAIL-INTEREST".  For general help, send email to
> [EMAIL PROTECTED] and include in the body of the message "help".

===========================================================================
To unsubscribe, send email to [EMAIL PROTECTED] and include in the body
of the message "signoff JAVAMAIL-INTEREST".  For general help, send email to
[EMAIL PROTECTED] and include in the body of the message "help".