Folder object throws IllegalStateException

Question

I am writing an email program which fetches the mail from Gmail. I have written the below mentioned code to fetch the name of all the folders of a particular client. when the servlet is loaded on the server, after that on the first (on servlet) the code marked (1) and (2) works fine, i.e the Folder object is created but on the subsequent hits, the folder object is not created. It throws an exception:
java.lang.illegalStateException:not connected
Why I am not been able to get the Folder object on subsequent hits?
     public ArrayList getCustomFolders(double pin){
                     System.out.println("Getting the name of all folders...");
          String username=(String)username_pin.get(pin);
          HashMap mapmap=(HashMap)map.get(username);
          Store store=(Store)mapmap.get("store");
          ArrayList folders=new ArrayList();
                               try {
               Folder folder=store.getDefaultFolder();---------------(1)
                Folder f[]=folder.list();-------------------------------------(2)
                                                 System.out.print("Folder: ");-------------------//this line is not printed after he first hit.
               for(Folder f1:f){
                    String foldername=f1.getFullName();
                    System.out.print(foldername+",  ");
                    folders.add(foldername);
                    if(f1.HOLDS_FOLDERS!=0){
                         Folder subfolders[]=f1.list();
                         for(Folder sub:subfolders){
                              System.out.print(sub.getFullName()+" ,");
                              folders.add(sub.getFullName());
          } catch (MessagingException e) {
               System.out.println("Exception caught while fetching the list of folders");
          }catch(Exception e){
               System.out.println("Exception caught"+e);
          return folders;
     }Edited by: carox on Mar 23, 2010 2:55 AM
Edited by: carox on Mar 23, 2010 3:05 AM
Edited by: carox on Mar 23, 2010 3:06 AM
Edited by: carox on Mar 23, 2010 3:07 AM

Answer 1

Because the Store has been closed. Why was it closed? I don't know. I can't see enough of your
application to tell, but I'm sure you can figure it out. Note that if you leave it open for a long time
without using it, the server will close it.
Also, note that this code isn't doing what you expect:
if(f1.HOLDS_FOLDERS!=0){
What you meant was:
if ((f1.getType() & Folder.HOLDS_FOLDERS) != 0) {