Problem in connect to a store

Question

I use JavaMail1.3.2 to connect a pop3 store and receive mails. It seemed works OK in first 1 or 8 hours, and after, the process will halt at store.connect step or store.isConnected step,
For example:
while(true){
Log4J.getLogger().debug("Try to connect "+ userName + "'s store!");
while(!store.isConnected()){
try{
Log4J.getLogger().debug("Connect "+ userName + " store...");
store.connect();
Log4J.getLogger().debug("Connect to MailBox:"+ userName + " store OK!");
folder = store.getFolder(folderName);
Log4J.getLogger().debug("Got "+ userName + "'s folder OK!");
}catch(Exception e){
Log4J.getLogger().error("Connect to Mailbox:"+ userName + " store error:" + e.getMessage());
try {
Log4J.getLogger().info("Waite " + frequency/60000 + "minutes!");
Thread.sleep(frequency);
} catch (InterruptedException e1) {
Log4J.getLogger().error("Thread error:"+e1.getMessage());
try {
Log4J.getLogger().debug("Try to open "+ userName + "'s folder!");
�
While running some time, log will stop at �Try to connect username�s store� and no exception or other information output.
I've set           pro.put("mail.pop3.connectiontimeout",timeoutVal);
          pro.put("mail.pop3.timeout",timeoutVal);
and seemed it doesn't work.
Please help me, How does this happen and how to solve it? Thank you very much!

Answer 1

Hello,
I get exactly the same issue in my app :
I have a mail receiver class that looks like that :
public static Message[] receiveMessages()
          Message[] msgs = new Message[0];
          try
               log.info("Checking mail on "+CommProperties.getInstance().getPopHost()+"...");
               if(null==folder||!store.isConnected())
                    log.debug("Folder is null or store is not connected, reinitialization");
                    // -- Try to get hold of the default folder --
                    folder = getStore().getDefaultFolder();
                    if (folder == null) throw new Exception("No default folder");
                    log.debug("Getting INBOX");
                    // -- ...and its INBOX --
                    folder = folder.getFolder("INBOX");
                    if (folder == null) throw new Exception("No POP3 INBOX");
               log.debug("Open folder for R/W");
               // -- Open the folder for read-write --
               folder.open(Folder.READ_WRITE);
               log.debug("Getting messages");
               // -- Get the message wrappers and process them --
               msgs = folder.getMessages();
               if(msgs.length==0)
                    log.debug("...No new mail in INBOX");
               log.debug("End");
          catch (Exception ex)
               log.error("Error while retrieving messages",ex);
          return msgs;
public static Store getStore() {
          if(null==store || !store.isConnected())
               try
                    if(store!=null)
                         log.debug("Store not connected : closing");
                         store.close();
                    log.debug("Getting pop3 Store");
                    store = getSession().getStore("pop3");
                    log.debug("Connectting pop3 Store");
                    store.connect(CommProperties.getInstance().getPopHost(), CommProperties.getInstance().getPopUsername(), CommProperties.getInstance().getPopPassword());
               catch(Exception ex)
                    log.error("Error while getting store",ex);
          return store;
In this case one session and folder are created. The class detects when a disconnection appears and is able to reconnect.
This method is called using a jboss service set to run one time a minute.
When deployed, the receive process runs up to 15 days without interruption. I see in the logs that sometimes, folder gets disconnected and is then reconnected without problem.
However, after 15 days (sometimes more, sometimes less), the app suddenly freezes after 'log.info("Checking mail on "+CommProperties.getInstance().getPopHost()+"...");'
So the freeze is due to the "store.isConnected()" not responding...
Unfortunately, i haven't got any solution. I tried several connect processes (connect/disconnect folder and session each time, reconnect folder each time...) but nothing seems to impact the issue.
So, guys, any help is very welcome! :-)
Thanks
Stephane