IMAP: test session expiration on each command, get a new session on expiration

git-svn-id: http://svn.code.sf.net/p/davmail/code/trunk@741 3d1905a2-6b24-0410-a738-b14d5a86fcbd

src/java/davmail/exchange/ExchangeSessionFactory.java

@@ -124,6 +124,40 @@ public final class ExchangeSessionFactory {
         return session;
     }
 
+    /**
+     * Get a non expired session.
+     * If the current session is not expired, return current session, else try to create a new session
+     *
+     * @param currentSession current session
+     * @param userName       user login
+     * @param password       user password
+     * @return authenticated session
+     * @throws IOException on error
+     */
+    public static ExchangeSession getInstance(ExchangeSession currentSession, String userName, String password)
+            throws IOException {
+        ExchangeSession session = currentSession;
+        try {
+            if (session.isExpired()) {
+                session = null;
+                String baseUrl = Settings.getProperty("davmail.url");
+                PoolKey poolKey = new PoolKey(baseUrl, userName, password);
+                // expired session, remove from cache
+                synchronized (LOCK) {
+                    POOL_MAP.remove(poolKey);
+                }
+                session = getInstance(userName, password);
+            }
+        } catch (DavMailAuthenticationException exc) {
+            throw exc;
+        } catch (DavMailException exc) {
+            throw exc;
+        } catch (Exception exc) {
+            handleNetworkDown(exc);
+        }
+        return session;
+    }
+
     /**
      * Send a request to Exchange server to check current settings.
      *

src/java/davmail/imap/ImapConnection.java

@@ -126,6 +126,8 @@ public class ImapConnection extends AbstractConnection {
                             if (state != State.AUTHENTICATED) {
                                 sendClient(commandId + " BAD command authentication required");
                             } else {
+                                // check for expired session
+                                session = ExchangeSessionFactory.getInstance(session, userName, password);
                                 if ("lsub".equalsIgnoreCase(command) || "list".equalsIgnoreCase(command)) {
                                     if (tokens.hasMoreTokens()) {
                                         String folderContext = BASE64MailboxDecoder.decode(tokens.nextToken());